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Mason NL, Szabo A, Kuypers KPC, Mallaroni PA, de la Torre Fornell R, Reckweg JT, Tse DHY, Hutten NRPW, Feilding A, Ramaekers JG. Psilocybin induces acute and persisting alterations in immune status in healthy volunteers: An experimental, placebo-controlled study. Brain Behav Immun 2023; 114:299-310. [PMID: 37689275 DOI: 10.1016/j.bbi.2023.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 09/11/2023] Open
Abstract
Patients characterized by stress-related disorders such as depression display elevated circulating concentrations of pro-inflammatory cytokines and a hyperactive HPA axis. Psychedelics are demonstrating promising results in treatment of such disorders, however the mechanisms of their therapeutic effects are still unknown. To date the evidence of acute and persisting effects of psychedelics on immune functioning, HPA axis activity in response to stress, and associated psychological outcomes is preliminary. To address this, we conducted a placebo-controlled, parallel group design comprising of 60 healthy participants who received either placebo (n = 30) or 0.17 mg/kg psilocybin (n = 30). Blood samples were taken to assess acute and persisting (7 day) changes in immune status. Seven days' post-administration, participants in each treatment group were further subdivided: 15 underwent a stress induction protocol, and 15 underwent a control protocol. Ultra-high field (7-Tesla) magnetic resonance spectroscopy was used to assess whether acute changes in glutamate or glial activity were associated with changes in immune functioning. Finally, questionnaires assessed persisting self-report changes in mood and social behavior. Psilocybin immediately reduced concentrations of the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α), while other inflammatory markers (interleukin (IL)- 1β, IL-6, and C-reactive protein (CRP)) remained unchanged. Seven days later, TNF-α concentrations returned to baseline, while IL-6 and CRP concentrations were persistently reduced in the psilocybin group. Changes in the immune profile were related to acute neurometabolic activity as acute reductions in TNF-α were linked to lower concentrations of glutamate in the hippocampus. Additionally, the more of a reduction in IL-6 and CRP seven days after psilocybin, the more persisting positive mood and social effects participants reported. Regarding the stress response, after a psychosocial stressor, psilocybin did not significantly alter the stress response. Results are discussed in regards to the psychological and therapeutic effects of psilocybin demonstrated in ongoing patient trials.
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Affiliation(s)
- N L Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
| | - A Szabo
- Norwegian Centre for Mental Disorders Research (NORMENT), Institute of Clinical Medicine, University of Oslo, and Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway; KG Jebsen Centre for Neurodevelopmental Disorders, University of Oslo, Oslo, Norway
| | - K P C Kuypers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - P A Mallaroni
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - R de la Torre Fornell
- Integrative Pharmacology and Systems Neurosciences Research Group. Neurosciences Program. Hospital del Mar Medical Research Institute. Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra. Dr. Aiguader 88, 08003 Barcelona, Spain
| | - J T Reckweg
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - D H Y Tse
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - N R P W Hutten
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - A Feilding
- The Beckley Foundation, Beckley Park, Oxford, OX3 9SY, United Kingdom
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
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Reckweg JT, Uthaug MV, Szabo A, Davis AK, Lancelotta R, Mason NL, Ramaekers JG. The clinical pharmacology and potential therapeutic applications of 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT). J Neurochem 2022; 162:128-146. [PMID: 35149998 PMCID: PMC9314805 DOI: 10.1111/jnc.15587] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/06/2022] [Accepted: 02/07/2022] [Indexed: 11/26/2022]
Abstract
5‐methoxy‐N,N‐dimethyltryptamine (5‐MeO‐DMT) is a naturally occurring tryptamine that primarily acts as an agonist at the 5‐HT1A and 5‐HT2A receptors, whereby affinity for the 5‐HT1A subtype is highest. Subjective effects following 5‐MeO‐DMT administration include distortions in auditory and time perception, amplification of emotional states, and feelings of ego dissolution that usually are short‐lasting, depending on the route of administration. Individual dose escalation of 5‐MeO‐DMT reliably induces a “peak” experience, a state thought to be a core predictor of the therapeutic efficacy of psychedelics. Observational studies and surveys have suggested that single exposure to 5‐MeO‐DMT can cause rapid and sustained reductions in symptoms of depression, anxiety, and stress. 5‐MeO‐DMT also stimulates neuroendocrine function, immunoregulation, and anti‐inflammatory processes, which may contribute to changes in mental health outcomes. To date, only one clinical trial has been published on 5‐MeO‐DMT, demonstrating the safety of vaporized dosing up to 18 mg. Importantly, the rapid onset and short duration of the 5‐MeO‐DMT experience may render it more suitable for individual dose‐finding strategies compared with longer‐acting psychedelics. A range of biotech companies has shown an interest in the development of 5‐MeO‐DMT formulations for a range of medical indications, most notably depression. Commercial development will therefore be the most important resource for bringing 5‐MeO‐DMT to the clinic. However, fundamental research will also be needed to increase understanding of the neurophysiological and neural mechanisms that contribute to the potential clinical effects of 5‐MeO‐DMT and its sustainability and dissemination over time. Such studies are less likely to be conducted as part of drug development programs and are more likely to rely on independent, academic initiatives.
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Affiliation(s)
- J T Reckweg
- Faculty of Psychology and Neuroscience, Dept of Neuropsychology and psychopharmacology, Maastricht University, The Netherlands
| | - M V Uthaug
- Faculty of Psychology and Neuroscience, Dept of Neuropsychology and psychopharmacology, Maastricht University, The Netherlands
| | - A Szabo
- Norwegian Centre for Mental Disorders Research (NORMENT), Institute of Clinical Medicine, University of Oslo, and Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway.,KG Jebsen Centre for Neurodevelopmental Disorders, University of Oslo, Oslo, Norway
| | - A K Davis
- Center for Psychedelic Drug Research and Education, College of Social Work, The Ohio State University, Columbus, OH, USA.,Center for Psychedelic and Consciousness Research, Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - R Lancelotta
- Center for Psychedelic Drug Research and Education, College of Social Work, The Ohio State University, Columbus, OH, USA
| | - N L Mason
- Faculty of Psychology and Neuroscience, Dept of Neuropsychology and psychopharmacology, Maastricht University, The Netherlands
| | - J G Ramaekers
- Faculty of Psychology and Neuroscience, Dept of Neuropsychology and psychopharmacology, Maastricht University, The Netherlands
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Hutten NRPW, Arkell TR, Vinckenbosch F, Schepers J, Kevin RC, Theunissen EL, Kuypers KPC, McGregor IS, Ramaekers JG. Cannabis containing equivalent concentrations of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) induces less state anxiety than THC-dominant cannabis. Psychopharmacology (Berl) 2022; 239:3731-3741. [PMID: 36227352 PMCID: PMC9584997 DOI: 10.1007/s00213-022-06248-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 09/24/2022] [Indexed: 11/29/2022]
Abstract
RATIONALE Delta-9-tetrahydrocannabinol (THC), an active component of cannabis, can cause anxiety in some users during intoxication. Cannabidiol (CBD), another constituent of cannabis, has anxiolytic properties suggesting that cannabis products containing CBD in addition to THC may produce less anxiety than THC-only products. Findings to date around this issue have been inconclusive and could conceivably depend on moderating factors such as baseline anxiety levels in users. OBJECTIVE The present study examined whether anxiety following single doses of vaporised THC, CBD and THC/CBD might be explained by state and trait anxiety levels at baseline. METHODS A placebo-controlled, randomised, within-subjects study including 26 healthy recreational cannabis users tested the effects of vaporised THC-dominant cannabis (13.75 mg THC), CBD-dominant cannabis (13.75 mg CBD), THC/CBD-equivalent cannabis (13.75 mg THC/13.75 mg CBD) and placebo cannabis on anxiety. Self-rated trait anxiety was assessed with the State-Trait Anxiety Inventory (STAI). State levels of anxiety were objectively assessed with a computer-based emotional Stroop task (EST) and subjectively rated with the STAI-state questionnaire and a visual analogue scale. RESULTS Both THC and THC/CBD significantly increased self-rated state anxiety compared to placebo. State anxiety after THC/CBD was significantly lower than after THC alone. THC-induced anxiety was independent of anxiety at baseline. When baseline anxiety was low, CBD completely counteracted THC-induced anxiety; however, when baseline anxiety was high, CBD did not counteract THC-induced anxiety. There were no effects of any treatment condition on the EST. CONCLUSION Overall, the study demonstrated that the THC/CBD-equivalent cannabis induces less state anxiety than THC-dominant cannabis.
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Affiliation(s)
- Nadia R. P. W. Hutten
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, Netherlands
| | - T. R. Arkell
- Centre for Human Psychopharmacology, Swinburne University of Technology, Melbourne, VIC Australia
| | - F. Vinckenbosch
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, Netherlands
| | - J. Schepers
- Department of Methodology & Statistics, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, Netherlands
| | - R. C. Kevin
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW Australia
| | - E. L. Theunissen
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, Netherlands
| | - K. P. C. Kuypers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, Netherlands
| | - I. S. McGregor
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW Australia
| | - J. G. Ramaekers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, Netherlands
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van Oorsouw K, Toennes SW, Ramaekers JG. Therapeutic effect of an ayahuasca analogue in clinically depressed patients: a longitudinal observational study. Psychopharmacology (Berl) 2022; 239:1839-1852. [PMID: 35072760 PMCID: PMC8785027 DOI: 10.1007/s00213-021-06046-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 12/16/2021] [Indexed: 11/25/2022]
Abstract
RATIONALE Studies have suggested mental health improvements following the use of the psychotropic plant concoction ayahuasca in non-clinical and clinical samples. OBJECTIVES The present observational study assessed depressive symptomatology in 20 clinically depressed patients (symptom score > 13 on the Beck's Depression Inventory) before attendance of an ayahuasca ceremony and 1 month and 1 year after. Secondary measures included ratings of altered states of consciousness and ego dissolution during the ayahuasca ceremony as well as global measures of mindfulness, satisfaction with life, depression, anxiety, and stress. RESULTS Twenty participants completed baseline and 1-day follow-up, 19 completed measures at 1-month follow-up, and 17 completed measures at 1-year follow-up. BDI scores reduced from baseline (M = 22.7) to all post-ceremony measures (Ms 11.45, 12.89, and 8.88, for 1-day, 1-month, and 1-year follow-up, respectively). After 1 day, 12/20 participants were in remission (BDI < 13). Remission rates after 1 month and 1 year were 13/19 and 12/17, respectively. Three participants remained mildly depressed (BDI 14-19) at the 1-month and 1-year follow-up. Two participants did not respond and remained at a moderate/severe level of depression at 1-year follow-up. Reductions on the secondary mental health measures and increases in mindfulness and satisfaction with life were found up to 1 year post-ceremony. Improvements in clinical depression and mental health correlated with levels of experienced ego dissolution and oceanic boundlessness during the ceremony up to 1 month after the ceremony. Engagement in additional mental health treatments or use of another psychedelic during study participation may have contributed to improved mental health ratings at 1-year follow-up. CONCLUSION Ayahuasca produces long-term mental health improvements in clinically depressed patients, which highlights its therapeutic potential.
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Affiliation(s)
- Kim van Oorsouw
- Faculty of Psychology and Neuroscience, Department of Clinical Psychological Science, Maastricht University, Maastricht, The Netherlands.
| | - S. W. Toennes
- Institute of Legal Medicine, Goethe University of Frankfurt, Frankfurt, Germany
| | - J. G. Ramaekers
- Faculty of Psychology and Neuroscience, Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, The Netherlands
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van der Sluiszen NNJJM, Urbanus B, Lammers GJ, Overeem S, Ramaekers JG, Vermeeren A. On-the-road driving performance of patients with central disorders of hypersomnolence. Traffic Inj Prev 2021; 22:120-126. [PMID: 33543997 DOI: 10.1080/15389588.2020.1862804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 11/03/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
INTRODUCTION Excessive Daytime Sleepiness is a core symptom of narcolepsy and idiopathic hypersomnia, which impairs driving performance. Adequate treatment improves daytime alertness, but it is unclear whether driving performance completely normalizes. This study compares driving performance of patients with narcolepsy and idiopathic hypersomnia receiving treatment to that of healthy controls. METHODS Patients diagnosed with narcolepsy type 1 (NT1, n = 33), narcolepsy type 2 (NT2, n = 7), or idiopathic hypersomnia (IH, n = 6) performed a standardized one-hour on-the-road driving test, measuring standard deviation of lateral position (SDLP). RESULTS Results showed that mean SDLP in patients did not differ significantly from controls, but the 95%CI of the mean difference (+1.02 cm) was wide (-0.72 to +2.76 cm). Analysis of subgroups, however, showed that mean SDLP in NT1 patients was significantly increased by 1.90 cm as compared to controls, indicating impairment. Moreover, four NT1 patients requested to stop the test prematurely due to self-reported somnolence, and two NT1 patients were stopped by the driving instructor for similar complaints. CONCLUSION Driving performance of NT1 patients may still be impaired, despite receiving treatment. No conclusions can be drawn for NT2 and IH patients due to the low sample sizes of these subgroups. In clinical practice, determination of fitness to drive for these patients should be based on an individual assessment in which also coping strategies are taken into account.
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Affiliation(s)
- N N J J M van der Sluiszen
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - B Urbanus
- Stichting Epilepsie Instelling Nederland (SEIN), Heemstede, The Netherlands
| | - G J Lammers
- Stichting Epilepsie Instelling Nederland (SEIN), Heemstede, The Netherlands
- Department of Neurology, Leiden University Medical Centre, Leiden, The Netherlands
| | - S Overeem
- Sleep Medicine Center Kempenhaeghe, Heeze, The Netherlands
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - A Vermeeren
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
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Mason NL, Kuypers KPC, Müller F, Reckweg J, Tse DHY, Toennes SW, Hutten NRPW, Jansen JFA, Stiers P, Feilding A, Ramaekers JG. Me, myself, bye: regional alterations in glutamate and the experience of ego dissolution with psilocybin. Neuropsychopharmacology 2020; 45:2003-2011. [PMID: 32446245 PMCID: PMC7547711 DOI: 10.1038/s41386-020-0718-8] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 05/14/2020] [Indexed: 01/21/2023]
Abstract
There is growing interest in the therapeutic utility of psychedelic substances, like psilocybin, for disorders characterized by distortions of the self-experience, like depression. Accumulating preclinical evidence emphasizes the role of the glutamate system in the acute action of the drug on brain and behavior; however this has never been tested in humans. Following a double-blind, placebo-controlled, parallel group design, we utilized an ultra-high field multimodal brain imaging approach and demonstrated that psilocybin (0.17 mg/kg) induced region-dependent alterations in glutamate, which predicted distortions in the subjective experience of one's self (ego dissolution). Whereas higher levels of medial prefrontal cortical glutamate were associated with negatively experienced ego dissolution, lower levels in hippocampal glutamate were associated with positively experienced ego dissolution. Such findings provide further insights into the underlying neurobiological mechanisms of the psychedelic, as well as the baseline, state. Importantly, they may also provide a neurochemical basis for therapeutic effects as witnessed in ongoing clinical trials.
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Affiliation(s)
- N L Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands.
| | - K P C Kuypers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - F Müller
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands
- Department of Psychiatry (UPK), University of Basel, Basel, Switzerland
| | - J Reckweg
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - D H Y Tse
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - S W Toennes
- Institute of Legal Medicine, University of Frankfurt, Kennedyallee 104, D-60596, Frankfurt/Main, Germany
| | - N R P W Hutten
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - J F A Jansen
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+ (MUMC+), Maastricht, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University Medical Center, P. Debyelaan 25, Maastricht, the Netherlands
| | - P Stiers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - A Feilding
- The Beckley Foundation, Beckley Park, Oxford, OX3 9SY, UK
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands.
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Ramaekers JG, Mason NL, Theunissen EL. Blunted highs: Pharmacodynamic and behavioral models of cannabis tolerance. Eur Neuropsychopharmacol 2020; 36:191-205. [PMID: 32014378 DOI: 10.1016/j.euroneuro.2020.01.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 12/22/2019] [Accepted: 01/12/2020] [Indexed: 02/07/2023]
Abstract
Acute exposure to cannabis comes with neurocognitive impairment, leading to increased risk of human error and injury. Evidence however indicates that such acute effects are less prominent in chronic users, suggesting cannabis tolerance. Models of cannabis tolerance stress the importance of neurobiological or behavioral adaptations following repeated cannabis exposure. The pharmacodynamic model relates neuroadaptive changes in the brain to a blunted response to cannabis. Downregulation of CB1 receptors in chronic cannabis users has been associated with a normalization of dopaminergic output from the ventral tegmental area to the mesolimbic circuit, and a reduction of impairment during acute cannabis exposure. Such neuroadaptions are absent in occasional users, who show strong increments of dopamine and glutamate levels in the striatum, a loss of functional connectivity within the mesolimbic circuit and neurocognitive impairments when exposed to cannabis. Evidence for a behavioral model of cannabis tolerance that poses that users can have volitional control to overcome functional impairment during cannabis intoxication is relatively weak, and at best shows limited control over a limited number of behavioral functions. Cannabis tolerance is most likely to occur in users that consume high doses of cannabis continuously, at a high pace, for a prolonged period of time. Knowledge on frequency, dose and duration of cannabis use that is needed to achieve, maintain or lessen tolerance however is very limited, but will be of importance in the context of cannabis therapeutics and in legal settings when evaluating the impact of cannabis exposure on human function.
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Affiliation(s)
- J G Ramaekers
- Faculty of Psychology and Neuroscience, Department of Neuropsychology and Psychopharmacology, Maastricht University, the Netherlands.
| | - N L Mason
- Faculty of Psychology and Neuroscience, Department of Neuropsychology and Psychopharmacology, Maastricht University, the Netherlands
| | - E L Theunissen
- Faculty of Psychology and Neuroscience, Department of Neuropsychology and Psychopharmacology, Maastricht University, the Netherlands
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8
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Vinckenbosch FRJ, Vermeeren A, Verster JC, Ramaekers JG, Vuurman EF. Validating lane drifts as a predictive measure of drug or sleepiness induced driving impairment. Psychopharmacology (Berl) 2020; 237:877-886. [PMID: 31897572 PMCID: PMC7036056 DOI: 10.1007/s00213-019-05424-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 12/03/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND Standard deviation of lateral position (SDLP) has been accepted as a reliable parameter for measuring driving impairment due to lowered vigilance caused by sleepiness or the use of sedating drugs. Recently, lane drifts were proposed as an additional outcome measure quantifying momentary lapses of attention. The purpose of this study was to validate lane drifts as outcome measure of driver impairment in a large data pool from two independent research centers. METHODS Data from 11 placebo-controlled studies that assessed the impact of alcohol, hypnotics, and sleep deprivation on actual driving performance were pooled. In total, 717 on-the-road tests performed by 315 drivers were subjected to an automated algorithm to detect occurrences of lane drifts. Lane drifts were defined as deviations > 100 cm from the mean (LDmlp) and from the absolute lateral position (LDalp) for 8 s. RESULTS The number of LDmlp was low and did not differ between treatments and baseline, i.e., 14 vs. 3 events, respectively. LDalp were frequent and significantly higher during treatment relative to baseline, i.e., 1646 vs. 470 events. The correlation between LDalp and SDLP in the treatment conditions was very high (rs = 0.77). The frequency of the occurrence of treatment-induced lane drifts however depended on baseline SDLP of drivers, whereas treatment-induced changes in SDLP occurred independent of baseline SDLP. CONCLUSION LDmlp is not useful as an outcome measure of driver impairment due to its rare occurrence, even when treatment-induced increments in SDLP are evident. Treatment effects on LDalp and SDLP are closely related.
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Affiliation(s)
- F. R. J. Vinckenbosch
- Department of neuropsychology and psychopharmacology, Maastricht University, Maastricht, The Netherlands
| | - A. Vermeeren
- Department of neuropsychology and psychopharmacology, Maastricht University, Maastricht, The Netherlands
| | - J. C. Verster
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands ,Division of Pharmacology, Utrecht University, 3584CG, Utrecht, The Netherlands ,Centre for Human Psychopharmacology, Swinburne University, Melbourne, Australia
| | - J. G. Ramaekers
- Department of neuropsychology and psychopharmacology, Maastricht University, Maastricht, The Netherlands
| | - E. F. Vuurman
- Department of neuropsychology and psychopharmacology, Maastricht University, Maastricht, The Netherlands
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Kuypers K, Verkes RJ, van den Brink W, van Amsterdam J, Ramaekers JG. Intoxicated aggression: Do alcohol and stimulants cause dose-related aggression? A review. Eur Neuropsychopharmacol 2020; 30:114-147. [PMID: 29941239 DOI: 10.1016/j.euroneuro.2018.06.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 05/23/2018] [Accepted: 06/02/2018] [Indexed: 12/30/2022]
Abstract
RATIONALE Violence and drug use are significant public health challenges that are strongly linked. It is known that alcohol plays a major role in the causation of unnatural deaths and that stimulants like cocaine and amphetamine are often implicated in aggressive acts or violence. However, a clear causal relationship between these substances and aggression, and more specifically a blood concentration threshold at which intoxicated aggression emerges is lacking. In case of a crime and subsequent law enforcement, knowledge about dose-response relationships could be of pivotal importance when evaluating the role of alcohol and drugs in aggressive offences. AIMS The present review aimed to determine whether there is a causal relation between intoxication with these psychoactive substances and aggression, and to define blood concentration thresholds above which these substances elicit aggression. METHODS Empirical articles published between 2013 and 2017 and review papers containing the predefined search strings were identified through searches in the PubMed and Embase databases and additional reference list searches. The complete search query yielded 1578 publications. Initially all articles were manually screened by title and abstract. Articles with irrelevant titles, given the selected search terms and review aims were discarded. Remaining articles were carefully studied and those that did not comply with the main objectives of this review were discarded. At the end of this process, 167 titles were found eligible for review. FINDINGS AND CONCLUSION While placebo-controlled experimental studies clearly showed a causal link between alcohol and aggression, it is evident that such a link has not yet been established for cocaine and amphetamines. In case of alcohol, it is clear that there are various individual and contextual factors that may contribute to the occurrence of an aggressive act during intoxication. A clear threshold blood alcohol concentration has not been defined yet for alcohol, but a statistically significant increase of aggression has been demonstrated at a dose of 0.75 g/kg and higher. Future studies into intoxicated aggression should include multiple doses of alcohol and stimulants and take into account individual and contextual factors.
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Affiliation(s)
- Kpc Kuypers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, PO Box 616, 6200 MD, Maastricht, The Netherlands.
| | - R J Verkes
- Radboud UMC, Psychiatry, Radboud University, Nijmegen, The Netherlands
| | - W van den Brink
- AMC Psychiatry, University of Amsterdam, Amsterdam, The Netherlands
| | | | - J G Ramaekers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, PO Box 616, 6200 MD, Maastricht, The Netherlands
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Gjerde H, Ramaekers JG, Mørland JG. Methodologies for establishing the relationship between alcohol/drug use and driving impairment - Differences between epidemiological, experimental, and real-case studies. Forensic Sci Rev 2019; 31:141-160. [PMID: 31270059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Experimental, epidemiological, and real-case studies have different advantages and limitations when used to study the effect of substance use on the risk for involvement in a road traffic crash. It is easier to perform well-controlled experimental studies than well-controlled epidemiological studies due to difficulties related to selection bias, information bias, and confounding. On the other hand, it is difficult or impossible to perform experimental studies using single and repeated substance doses similar to those used by drivers and problematic drugs users. Real-case studies indicate which substances may cause observed impairment and involvement in road traffic crashes and at which concentrations; however, those studies cannot be used to quantify crash risks or determine causality. All three types of studies are needed to obtain a broad and complete picture as they may complement each other when assessing the effects of substance use on road traffic safety.
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Affiliation(s)
- H Gjerde
- Department of Forensic Sciences, Oslo University Hospital, Oslo, Norway
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, University of Maastricht Maastricht, The Netherlands
| | - J G Mørland
- Division of Health Data and Digitalization, Norwegian Institute of Public Health, Oslo, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
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11
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Kuypers KPC, De Sousa Fernandes Perna EB, Theunissen EL, Toennes SW, Mason NL, Hutten NRPW, Ramaekers JG. A First-in-Man Study with 4-Fluoroamphetamine Demonstrates it Produces a Mild Psychedelic State. J Psychoactive Drugs 2019; 51:225-235. [DOI: 10.1080/02791072.2019.1569286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- K. P. C. Kuypers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - E. B. De Sousa Fernandes Perna
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - E. L Theunissen
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - S. W. Toennes
- Department of Forensic Toxicology, Institute of Legal Medicine, Goethe University of Frankfurt, Frankfurt, Germany
| | - N. L. Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - N. R. P. W. Hutten
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - J. G. Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
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12
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Uthaug MV, van Oorsouw K, Kuypers KPC, van Boxtel M, Broers NJ, Mason NL, Toennes SW, Riba J, Ramaekers JG. Sub-acute and long-term effects of ayahuasca on affect and cognitive thinking style and their association with ego dissolution. Psychopharmacology (Berl) 2018; 235:2979-2989. [PMID: 30105399 PMCID: PMC6182612 DOI: 10.1007/s00213-018-4988-3] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 07/24/2018] [Indexed: 02/04/2023]
Abstract
RATIONALE Ayahuasca is a psychotropic plant tea from South America used for religious purposes by indigenous people of the Amazon. Increasing evidence indicates that ayahuasca may have therapeutic potential in the treatment of mental health disorders and can enhance mindfulness-related capacities. Most research so far has focused on acute and sub-acute effects of ayahuasca on mental health-related parameters and less on long-term effects. OBJECTIVES The present study aimed to assess sub-acute and long-term effects of ayahuasca on well-being and cognitive thinking style. The second objective was to assess whether sub-acute and long-term effects of ayahuasca depend on the degree of ego dissolution that was experienced after consumption of ayahuasca. RESULTS Ayahuasca ceremony attendants (N = 57) in the Netherlands and Colombia were assessed before, the day after, and 4 weeks following the ritual. Relative to baseline, ratings of depression and stress significantly decreased after the ayahuasca ceremony and these changes persisted for 4 weeks. Likewise, convergent thinking improved post-ayahuasca ceremony up until the 4 weeks follow-up. Satisfaction with life and several aspects of mindfulness increased the day after the ceremony, but these changes failed to reach significance 4 weeks after. Changes in affect, satisfaction with life, and mindfulness were significantly correlated to the level of ego dissolution experienced during the ayahuasca ceremony and were unrelated to previous experience with ayahuasca. CONCLUSION It is concluded that ayahuasca produces sub-acute and long-term improvements in affect and cognitive thinking style in non-pathological users. These data highlight the therapeutic potential of ayahuasca in the treatment of mental health disorders, such as depression.
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Affiliation(s)
- M V Uthaug
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
| | - K van Oorsouw
- Department of Clinical Sciences, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - K P C Kuypers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - M van Boxtel
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
- Department of Psychiatry and Psychology, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - N J Broers
- Department of Methodology and Statistics, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - N L Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - S W Toennes
- Institute of Legal Medicine, Goethe University of Frankfurt, Frankfurt, Germany
| | - J Riba
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
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Kuypers KPC, de Sousa Fernandes Perna EB, Dolder PC, Toennes SW, Theunissen EL, Mason NL, Hutten NRPW, Ramaekers JG. Drug liking and wanting, not impulsive action or reflection is increased by 4-fluoroamphetamine. Psychopharmacology (Berl) 2018; 235:2349-2356. [PMID: 29855660 PMCID: PMC6061712 DOI: 10.1007/s00213-018-4931-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 05/22/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND New psychoactive substances (NPS) are chemical analogues designed to mimic the effects of various classic recreational drugs of abuse including MDMA, LSD, and cannabis. NPS use is associated with concern about the acute and longer-term effects particular substances might have, with abuse and addiction as potential consequences. Impulsivity and sensitivity to the rewarding effects of drugs have been considered as risk factors for drug abuse. In light of the popularity of 4-fluoroamphetamine (4-FA), it is important to assess whether 4-FA can lead to subjective drug liking and wanting, and impulsive behavior, all factors contributing to the abuse likelihood of a substance. METHODS A placebo-controlled 2-way crossover study in 12 healthy poly-drug using participants was conducted to test subjective and behavioral effects of 4-FA (100 mg). 4-FA concentrations were determined in serum up to 12 h after administration and two impulsivity tasks and two drug experience questionnaires assessing drug liking and wanting, and good and bad drug effect, were administered between 1 and 11 h post-administration. RESULTS Findings showed that 4-FA did not affect impulsive behavior. Self-ratings of drug liking and wanting and good drug effect were increased 1 h after administration; this effect was absent 11 h after drug intake. DISCUSSION AND CONCLUSION To conclude, 4-FA (single dose) increased self-rated liking and wanting, which is known to contribute to the abuse likelihood of a substance; however, it left another factor impulsive behavior unaffected. It has to be noted that the current picture is limited and might change with increased sample size, and/or different 4-FA doses. CLINICAL TRIAL REGISTRATION Trial acronym: 4-FA. URL: http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=6164 . Registration number: NTR6164 (Dutch clinical trial registry number).
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Affiliation(s)
- K P C Kuypers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P. O. Box 616, 6200 MD, Maastricht, the Netherlands.
| | - E B de Sousa Fernandes Perna
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P. O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - P C Dolder
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P. O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - S W Toennes
- Department of Forensic Toxicology, Institute of Legal Medicine, Goethe University of Frankfurt, Frankfurt, Germany
| | - E L Theunissen
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P. O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - N L Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P. O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - N R P W Hutten
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P. O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P. O. Box 616, 6200 MD, Maastricht, the Netherlands
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Haijen E, Farre M, de la Torre R, Pastor A, Olesti E, Pizarro N, Ramaekers JG, Kuypers KPC. Peripheral endocannabinoid concentrations are not associated with verbal memory impairment during MDMA intoxication. Psychopharmacology (Berl) 2018; 235:709-717. [PMID: 29143869 PMCID: PMC5847074 DOI: 10.1007/s00213-017-4787-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 11/07/2017] [Indexed: 11/04/2022]
Abstract
BACKGROUND Preclinical data have suggested involvement of the endocannabinoid (eCB) system in MDMA-induced memory impairment. Clinical research has shown that blockade of the 5-HT2 receptor nulls memory impairment during MDMA intoxication. Interestingly, studies have demonstrated that the eCB and the 5-HT system interact. It was hypothesized that MDMA would cause an increase in eCB concentrations together with a decrease in memory performance, and that combining MDMA with a 5-HT2 receptor blocker ketanserin would lead to a counteraction of the MDMA effects on eCB concentrations and memory. METHODS Twenty healthy recreational polydrug users entered a double-blind placebo-controlled within-subject study. Participants received a pre-treatment (ketanserin 40 mg, placebo) followed 30 min later by a treatment (MDMA 75 mg, placebo). Verbal memory was tested by means of a 30-word learning test. Endocannabinoid concentrations (anandamide (2-AG); N-arachidonylethanolamine (AEA)) were assessed in blood at baseline, before (90 min post-treatment) and after cognitive tests (150 min post-treatment). RESULTS Findings showed that MDMA impaired memory 90 min post-treatment in the word learning task. This effect was a replication of previous studies using the same dose of MDMA (75 mg) and the same learning paradigm. Contrary to our hypothesis, MDMA did not affect eCB concentrations, nor did ketanserin block MDMA-induced memory impairment. Ketanserin caused an increase in AEA concentrations, 180 min after administration. CONCLUSION Current findings suggest that peripherally measured endocannabinoids are not associated with the verbal memory deficit during MDMA intoxication. TRIAL REGISTRATION NUMBER NTR3691.
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Affiliation(s)
- E Haijen
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - M Farre
- Integrative Pharmacology & Neurosciences Systems Research Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain
- Universitat Autonoma de Barcelona, Barcelona, Spain
- Clinical Pharmacology, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - R de la Torre
- Integrative Pharmacology & Neurosciences Systems Research Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain
- Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBEROBN), Santiago de Compostela, Spain
- Universitat Pompeu Fabra, CEXS-UPF, Barcelona, Spain
| | - A Pastor
- Integrative Pharmacology & Neurosciences Systems Research Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain
- Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBEROBN), Santiago de Compostela, Spain
| | - E Olesti
- Integrative Pharmacology & Neurosciences Systems Research Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain
- Universitat Pompeu Fabra, CEXS-UPF, Barcelona, Spain
| | - N Pizarro
- Integrative Pharmacology & Neurosciences Systems Research Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain
- Universitat Autonoma de Barcelona, Barcelona, Spain
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - K P C Kuypers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
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15
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Kuypers KPC, de la Torre R, Farre M, Pizarro N, Xicota L, Ramaekers JG. Erratum to: MDMA-induced indifference to negative sounds is mediated by the 5-HT 2A receptor. Psychopharmacology (Berl) 2018; 235:605. [PMID: 28766260 PMCID: PMC6828455 DOI: 10.1007/s00213-017-4708-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- K. P. C. Kuypers
- 0000 0001 0481 6099grid.5012.6Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - R. de la Torre
- 0000 0004 1767 9005grid.20522.37Integrative Pharmacology and Neurosciences Systems Research Group, Institut Hospital del Mar d’Investigacions Mèdiques, Barcelona, Spain ,grid.484042.eSpanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBEROBN), Santiago de Compostela, Spain ,0000 0001 2172 2676grid.5612.0CEXS-UPF, Universitat Pompeu Fabra, Barcelona, Spain
| | - M. Farre
- 0000 0004 1767 9005grid.20522.37Integrative Pharmacology and Neurosciences Systems Research Group, Institut Hospital del Mar d’Investigacions Mèdiques, Barcelona, Spain ,grid.7080.fUniversitat Autonoma de Barcelona, Barcelona, Spain ,0000 0004 1767 6330grid.411438.bClinical Pharmacology, Hospital Universitari Germans Trias i Pujol, Badalona, Spain
| | - N. Pizarro
- 0000 0004 1767 9005grid.20522.37Integrative Pharmacology and Neurosciences Systems Research Group, Institut Hospital del Mar d’Investigacions Mèdiques, Barcelona, Spain ,grid.7080.fUniversitat Autonoma de Barcelona, Barcelona, Spain
| | - L. Xicota
- 0000 0004 1767 9005grid.20522.37Integrative Pharmacology and Neurosciences Systems Research Group, Institut Hospital del Mar d’Investigacions Mèdiques, Barcelona, Spain
| | - J. G. Ramaekers
- 0000 0001 0481 6099grid.5012.6Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
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Evers EA, Stiers P, Ramaekers JG. High reward expectancy during methylphenidate depresses the dopaminergic response to gain and loss. Soc Cogn Affect Neurosci 2017; 12:311-318. [PMID: 27677943 PMCID: PMC5390715 DOI: 10.1093/scan/nsw124] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 07/13/2016] [Accepted: 08/24/2016] [Indexed: 01/07/2023] Open
Abstract
Dopamine plays an important role in goal-directed behavior, through its modulatory influence on striatal neurons. It is unclear whether tonic dopamine levels, which regulate the vigor of acting, interact with the phasic dopamine response to reward that drives instrumental behavior. In a randomized placebo-controlled study in healthy volunteers, we show that methylphenidate, a drug that increases tonic dopamine levels, systematically reduced striatal phasic BOLD responses to gain and loss in a gambling task as measured with fMRI. It also increased response vigor and reward expectancy-related BOLD signals in the ventral striatum. These findings suggest that striatal tonic dopamine levels constitute an average reward expectation signal that modulates the phasic dopaminergic response to reward. This offers opportunities for treatment of behavioral disorders associated with abnormal reward sensitivity.
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Affiliation(s)
- E A Evers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, Maastricht 6229 ER, The Netherlands
| | - P Stiers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, Maastricht 6229 ER, The Netherlands
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, Maastricht 6229 ER, The Netherlands
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17
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Jongen S, Vermeeren A, van der Sluiszen NNJJM, Schumacher MB, Theunissen EL, Kuypers KPC, Vuurman EFPM, Ramaekers JG. A pooled analysis of on-the-road highway driving studies in actual traffic measuring standard deviation of lateral position (i.e., "weaving") while driving at a blood alcohol concentration of 0.5 g/L. Psychopharmacology (Berl) 2017; 234:837-844. [PMID: 28070617 PMCID: PMC5306436 DOI: 10.1007/s00213-016-4519-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 12/20/2016] [Indexed: 10/26/2022]
Abstract
INTRODUCTION The on-the-road highway driving test is generally regarded as a gold standard for assessing drug-induced driving impairment. The primary outcome measure is the standard deviation of lateral position (SDLP), a measure of road tracking error or "weaving". The test has been calibrated for incremental doses of alcohol almost 30 years ago in order to define the impact of drug-induced impairment in terms of blood alcohol concentration (BAC) equivalents. Drug-induced changes in SDLP exceeding 2.4 cm have been evaluated as clinically relevant ever since. The present analysis was conducted to assess the robustness of the alcohol effect in a range of on-the-road driving studies which have been conducted since the initial alcohol calibration study. METHODS The present study pooled data of 182 participants from nine placebo-controlled crossover studies who performed the highway driving test, while their BAC was at or just below the legal limit for drivers (i.e., 0.5 g/L). RESULTS Overall, mean SDLP increased with 2.5 cm (95% CI 2.0-2.9 cm). Equivalence testing showed that the clinical relevance criterion value of 2.4 cm fell well within the 95% CI in each individual study. Gender did not affect alcohol-induced changes in SDLP. DISCUSSION These results demonstrate the robustness and validity of the clinical relevance criterion for SDLP as measured during on-the-road driving.
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Affiliation(s)
- S. Jongen
- 0000 0001 0481 6099grid.5012.6Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6200 MD Maastricht, The Netherlands
| | - A. Vermeeren
- 0000 0001 0481 6099grid.5012.6Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6200 MD Maastricht, The Netherlands
| | - N. N. J. J. M. van der Sluiszen
- 0000 0001 0481 6099grid.5012.6Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6200 MD Maastricht, The Netherlands
| | - M. B. Schumacher
- Federal Highway Research Institute (BASt), Section U3/Traffic Psychology, Traffic Education, Bruederstrasse 53, D-51427 Bergisch Gladbach, Germany
| | - E. L. Theunissen
- 0000 0001 0481 6099grid.5012.6Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6200 MD Maastricht, The Netherlands
| | - K. P. C. Kuypers
- 0000 0001 0481 6099grid.5012.6Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6200 MD Maastricht, The Netherlands
| | - E. F. P. M. Vuurman
- 0000 0001 0481 6099grid.5012.6Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6200 MD Maastricht, The Netherlands
| | - J. G. Ramaekers
- 0000 0001 0481 6099grid.5012.6Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6200 MD Maastricht, The Netherlands
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de Sousa Fernandes Perna EB, Papaseit E, Pérez-Mañá C, Mateus J, Theunissen EL, Kuypers K, de la Torre R, Farré M, Ramaekers JG. Neurocognitive performance following acute mephedrone administration, with and without alcohol. J Psychopharmacol 2016; 30:1305-1312. [PMID: 27562197 DOI: 10.1177/0269881116662635] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Recreational use of mephedrone, alone and in combination with alcohol, has increased over the past years. Pharmacological properties of mephedrone share similarities with methylenedioxymethamphetamine (MDMA), but its effect on neurocognitive function has not been well established in humans. The present study assessed the effect of mephedrone alone and after co-administration with alcohol on neurocognitive function. It was hypothesised that mephedrone would improve psychomotor performance but impair memory performance, when administered alone. Neurocognitive performance was expected to be impaired following mephedrone when combined with alcohol. Eleven participants received single doses of 200 mg mephedrone or placebo combined with 0.8 g/kg alcohol or placebo. Neurocognitive performance was assessed at baseline (T0), at one hour (T1) and four hours after (T2) mephedrone administration, by means of the Divided Attention Task (DAT), Critical Tracking Task (CTT), and the Spatial Memory Test (SMT). Mephedrone intoxication impaired short-term spatial memory at T1 and improved critical tracking performance at T2 Mephedrone alone did not affect divided attention, but did show an interaction with alcohol on reaction time at T2 Reaction time decreased when mephedrone was combined with alcohol as compared to alcohol alone. Alcohol intoxication impaired both short- and long-term spatial memory at T1 and divided attention at T1 and T2 Critical tracking performance was not affected by alcohol intoxication. The current findings support the hypothesis that mephedrone improves psychomotor performance, impairs spatial memory and does not affect divided attention performance. Stimulatory effects of mephedrone were not sufficient to compensate for the impairing effects of alcohol on most performance parameters.
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Affiliation(s)
| | - E Papaseit
- Integrative Pharmacology & Neurosciences Systems Research Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain.,Universitat Autonoma de Barcelona, Barcelona, Spain.,Hospital Universitari Germans Trias i Pujol, Clinical Pharmacology, Badalona, Spain
| | - C Pérez-Mañá
- Integrative Pharmacology & Neurosciences Systems Research Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain.,Universitat Autonoma de Barcelona, Barcelona, Spain
| | - J Mateus
- Integrative Pharmacology & Neurosciences Systems Research Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain.,Universitat Autonoma de Barcelona, Barcelona, Spain
| | - E L Theunissen
- Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, the Netherlands
| | - Kpc Kuypers
- Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, the Netherlands
| | - R de la Torre
- Integrative Pharmacology & Neurosciences Systems Research Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain.,Spanish Biomedical Research Centre in Physiopathology of Obesity and Nutrition (CIBEROBN), Santiago de Compostela, Spain.,Universitat Pompeu Fabra, CEXS-UPF, Barcelona, Spain
| | - M Farré
- Integrative Pharmacology & Neurosciences Systems Research Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain.,Universitat Autonoma de Barcelona, Barcelona, Spain.,Hospital Universitari Germans Trias i Pujol, Clinical Pharmacology, Badalona, Spain
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, the Netherlands
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Ramaekers JG, van Wel JH, Spronk DB, Toennes SW, Kuypers KPC, Theunissen EL, Verkes RJ. Erratum: Cannabis and tolerance: acute drug impairment as a function of cannabis use history. Sci Rep 2016; 6:31939. [PMID: 27585721 PMCID: PMC5009429 DOI: 10.1038/srep31939] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Kuypers KPC, Riba J, de la Fuente Revenga M, Barker S, Theunissen EL, Ramaekers JG. Ayahuasca enhances creative divergent thinking while decreasing conventional convergent thinking. Psychopharmacology (Berl) 2016; 233:3395-403. [PMID: 27435062 PMCID: PMC4989012 DOI: 10.1007/s00213-016-4377-8] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 07/06/2016] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Ayahuasca is a South American psychotropic plant tea traditionally used in Amazonian shamanism. The tea contains the psychedelic 5-HT2A receptor agonist N,N-dimethyltryptamine (DMT), plus β-carboline alkaloids with monoamine oxidase-inhibiting properties. Increasing evidence from anecdotal reports and open-label studies indicates that ayahuasca may have therapeutic effects in treatment of substance use disorders and depression. A recent study on the psychological effects of ayahuasca found that the tea reduces judgmental processing and inner reactivity, classic goals of mindfulness psychotherapy. Another psychological facet that could potentially be targeted by ayahuasca is creative divergent thinking. This mode of thinking can enhance and strengthen psychological flexibility by allowing individuals to generate new and effective cognitive, emotional, and behavioral strategies. The present study aimed to assess the potential effects of ayahuasca on creative thinking. METHODS We visited two spiritual ayahuasca workshops and invited participants to conduct creativity tests before and during the acute effects of ayahuasca. In total, 26 participants consented. Creativity tests included the "pattern/line meanings test" (PLMT) and the "picture concept test" (PCT), both assessing divergent thinking and the latter also assessing convergent thinking. RESULTS While no significant effects were found for the PLMT, ayahuasca intake significantly modified divergent and convergent thinking as measured by the PCT. While convergent thinking decreased after intake, divergent thinking increased. CONCLUSIONS The present data indicate that ayahuasca enhances creative divergent thinking. They suggest that ayahuasca increases psychological flexibility, which may facilitate psychotherapeutic interventions and support clinical trial initiatives.
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Affiliation(s)
- K P C Kuypers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
| | - J Riba
- Human Experimental Neuropsychopharmacology, Sant Pau Institute of Biomedical Research, Barcelona, Spain
| | - M de la Fuente Revenga
- Human Experimental Neuropsychopharmacology, Sant Pau Institute of Biomedical Research, Barcelona, Spain
| | - S Barker
- Department of Comparative Biomedical Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - E L Theunissen
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
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21
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van der Sluiszen NNJJM, Vermeeren A, Jongen S, Theunissen EL, van Oers ACM, Van Leeuwen CJ, Maret A, Desforges C, Delarue A, Ramaekers JG. On-the-road driving performance after use of the antihistamines mequitazine and l-mequitazine, alone and with alcohol. Psychopharmacology (Berl) 2016; 233:3461-9. [PMID: 27488192 PMCID: PMC4989021 DOI: 10.1007/s00213-016-4386-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 07/18/2016] [Indexed: 12/02/2022]
Abstract
OBJECTIVE Previous studies demonstrated that mequitazine produces mild sedation after single doses. Its enantiomer, l-mequitazine, has a stronger potency for the H1 receptor. The aim of the current study was to assess the effects of l-mequitazine and mequitazine, alone and with alcohol, on driving. METHODS Twenty-five healthy volunteers were treated with l-mequitazine 2.5, 5.0 and 10 mg, mequitazine 10 mg and placebo, alone and in combination with alcohol in a double-blind crossover design. Driving performance was assessed using the standardized highway driving test in normal traffic. Its primary measure is the Standard Deviation of the Lateral Position (SDLP). Secondary measures consisted of an auditory word learning test during driving, and subjective measures of driving performance. RESULTS L-mequitazine 2.5 and 5.0 mg showed no effect on SDLP in the highway driving test, while SDLP significantly increased after l-mequitazine 10 mg (alone +1.59 cm; with alcohol +1.41 cm) and mequitazine 10 mg (with alcohol +1.17 cm). Alcohol significantly impaired all performance measures (SDLP +2.63 cm) but did not interact with the effects of treatment. Subjective measures indicated that participants were aware of the impairing effects of alcohol, but not of l-mequitazine and mequitazine. CONCLUSION L-mequitazine can be considered safe to drive in dosages of 2.5 and 5.0 mg. L-mequitazine 10 mg led to mild driving impairment. Alcohol impaired all performance measures and added to the effects of l-mequitazine and mequitazine.
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Affiliation(s)
- N N J J M van der Sluiszen
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, Maastricht, 6200 MD, The Netherlands.
| | - A Vermeeren
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, Maastricht, 6200 MD, The Netherlands
| | - S Jongen
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, Maastricht, 6200 MD, The Netherlands
| | - E L Theunissen
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, Maastricht, 6200 MD, The Netherlands
| | - A C M van Oers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, Maastricht, 6200 MD, The Netherlands
| | - C J Van Leeuwen
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, Maastricht, 6200 MD, The Netherlands
| | - A Maret
- Institut de Recherche Pierre Fabre, Ramonville, France
| | - C Desforges
- Institut de Recherche Pierre Fabre, Ramonville, France
| | - A Delarue
- Institut de Recherche Pierre Fabre, Ramonville, France
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, Maastricht, 6200 MD, The Netherlands
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Jongen S, Vuurman EFPM, Ramaekers JG, Vermeeren A. The sensitivity of laboratory tests assessing driving related skills to dose-related impairment of alcohol: A literature review. Accid Anal Prev 2016; 89:31-48. [PMID: 26802474 DOI: 10.1016/j.aap.2016.01.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 11/06/2015] [Accepted: 01/02/2016] [Indexed: 06/05/2023]
Abstract
Laboratory tests assessing driving related skills can be useful as initial screening tools to assess potential drug induced impairment as part of a standardized behavioural assessment. Unfortunately, consensus about which laboratory tests should be included to reliably assess drug induced impairment has not yet been reached. The aim of the present review was to evaluate the sensitivity of laboratory tests to the dose dependent effects of alcohol, as a benchmark, on performance parameters. In total, 179 experimental studies were included. Results show that a cued go/no-go task and a divided attention test with primary tracking and secondary visual search were consistently sensitive to the impairing effects at medium and high blood alcohol concentrations. Driving performance assessed in a simulator was less sensitive to the effects of alcohol as compared to naturalistic, on-the-road driving. In conclusion, replicating results of several potentially useful tests and their predictive validity of actual driving impairment should deserve further research. In addition, driving simulators should be validated and compared head to head to naturalistic driving in order to increase construct validity.
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Affiliation(s)
- S Jongen
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, The Netherlands.
| | - E F P M Vuurman
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, The Netherlands.
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, The Netherlands.
| | - A Vermeeren
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, The Netherlands.
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23
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De Sousa Fernandes Perna EB, Theunissen EL, Kuypers KPC, Toennes SW, Ramaekers JG. Subjective aggression during alcohol and cannabis intoxication before and after aggression exposure. Psychopharmacology (Berl) 2016; 233:3331-40. [PMID: 27422568 PMCID: PMC4988999 DOI: 10.1007/s00213-016-4371-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 06/29/2016] [Indexed: 11/18/2022]
Abstract
RATIONALE Alcohol and cannabis use have been implicated in aggression. Alcohol consumption is known to facilitate aggression, whereas a causal link between cannabis and aggression has not been clearly demonstrated. OBJECTIVES This study investigated the acute effects of alcohol and cannabis on subjective aggression in alcohol and cannabis users, respectively, following aggression exposure. Drug-free controls served as a reference. It was hypothesized that aggression exposure would increase subjective aggression in alcohol users during alcohol intoxication, whereas it was expected to decrease subjective aggression in cannabis users during cannabis intoxication. METHODS Heavy alcohol (n = 20) and regular cannabis users (n = 21), and controls (n = 20) were included in a mixed factorial study. Alcohol and cannabis users received single doses of alcohol and placebo or cannabis and placebo, respectively. Subjective aggression was assessed before and after aggression exposure consisting of administrations of the point-subtraction aggression paradigm (PSAP) and the single category implicit association test (SC-IAT). Testosterone and cortisol levels in response to alcohol/cannabis treatment and aggression exposure were recorded as secondary outcome measures. RESULTS Subjective aggression significantly increased following aggression exposure in all groups while being sober. Alcohol intoxication increased subjective aggression whereas cannabis decreased the subjective aggression following aggression exposure. Aggressive responses during the PSAP increased following alcohol and decreased following cannabis relative to placebo. Changes in aggressive feeling or response were not correlated to the neuroendocrine response to treatments. CONCLUSIONS It is concluded that alcohol facilitates feelings of aggression whereas cannabis diminishes aggressive feelings in heavy alcohol and regular cannabis users, respectively.
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Affiliation(s)
- E. B. De Sousa Fernandes Perna
- Department Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - E. L. Theunissen
- Department Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - K. P. C. Kuypers
- Department Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - S. W. Toennes
- Department of Forensic Toxicology, Institute of Legal Medicine, Goethe University of Frankfurt, Frankfurt, Germany
| | - J. G. Ramaekers
- Department Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands
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24
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Kuypers KPC, Steenbergen L, Theunissen EL, Toennes SW, Ramaekers JG. Emotion recognition during cocaine intoxication. Eur Neuropsychopharmacol 2015; 25:1914-21. [PMID: 26328908 DOI: 10.1016/j.euroneuro.2015.08.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 07/31/2015] [Accepted: 08/13/2015] [Indexed: 12/29/2022]
Abstract
Chronic or repeated cocaine use has been linked to impairments in social skills. It is not clear whether cocaine is responsible for this impairment or whether other factors, like polydrug use, distort the observed relation. We aimed to investigate this relation by means of a placebo-controlled experimental study. Additionally, associations between stressor-related activity (cortisol, cardiovascular parameters) induced by the biological stressor cocaine, and potential cocaine effects on emotion recognition were studied. Twenty-four healthy recreational cocaine users participated in this placebo-controlled within-subject study. Participants were tested between 1 and 2 h after treatment with oral cocaine (300 mg) or placebo. Emotion recognition of low and high intensity expressions of basic emotions (fear, anger, disgust, sadness, and happiness) was tested. Findings show that cocaine impaired recognition of negative emotions; this was mediated by the intensity of the presented emotions. When high intensity expressions of Anger and Disgust were shown, performance under influence of cocaine 'normalized' to placebo-like levels while it made identification of Sadness more difficult. The normalization of performance was most notable for participants with the largest cortisol responses in the cocaine condition compared to placebo. It was demonstrated that cocaine impairs recognition of negative emotions, depending on the intensity of emotion expression and cortisol response.
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Affiliation(s)
- K P C Kuypers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.
| | - L Steenbergen
- Department of Cognitive Psychology, Faculty of Social Sciences, Leiden University, Leiden, The Netherlands
| | - E L Theunissen
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - S W Toennes
- Department of Forensic Toxicology, Institute of Legal Medicine, Goethe University of Frankfurt, Frankfurt, Germany
| | - J G Ramaekers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands
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van Wel JHP, Spronk DB, Kuypers KPC, Theunissen EL, Toennes SW, Verkes RJ, Ramaekers JG. Psychedelic symptoms of cannabis and cocaine use as a function of trait impulsivity. J Psychopharmacol 2015; 29:324-34. [PMID: 25572345 DOI: 10.1177/0269881114563633] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Trait impulsivity has been linked to addiction in humans. It has been suggested that drug users with high trait impulsivity levels are more sensitive to subjective drug intoxication. This study assessed whether subjective response to drugs differs between drug users with normal or high levels of trait impulsivity. Regular drug users (N = 122) received doses of cocaine HCl, cannabis, and placebo in a three-way crossover study. Their mood, dissociative state, and psychedelic symptoms were measured with subjective rating scales (CADDS, Bowdle, POMS). Trait impulsivity was assessed with the Barratt Impulsiveness Scale. Cannabis increased dissociation and psychedelic state, as well as fatigue, confusion, depression and anxiety, and decreased arousal, positive mood, vigor, friendliness, and elation. Cocaine increased dissociation, psychedelic state, vigor, friendliness, elation, positive mood, anxiety and arousal, while decreasing fatigue. Only a few subjective items revealed a drug × trait impulsivity interaction, suggesting that psychedelic symptoms were most intense in high impulsivity subjects. Trait impulsiveness ratings were negatively correlated with ratings of vigor (r = -.197) and positively correlated with ratings of loss of thought control (r = .237) during cannabis intoxication. It is concluded that a broad association between trait impulsivity and psychedelic subjective drug experience appears to be absent.
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Affiliation(s)
- J H P van Wel
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - D B Spronk
- Department of Psychiatry (966), Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - K P C Kuypers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - E L Theunissen
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - S W Toennes
- Department of Forensic Toxicology, Institute of Legal Medicine, Goethe University of Frankfurt, Frankfurt, Germany
| | - R J Verkes
- Department of Psychiatry (966), Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
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26
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Veldstra JL, Bosker WM, de Waard D, Ramaekers JG, Brookhuis KA. Comparing treatment effects of oral THC on simulated and on-the-road driving performance: testing the validity of driving simulator drug research. Psychopharmacology (Berl) 2015; 232:2911-9. [PMID: 25957748 PMCID: PMC4513227 DOI: 10.1007/s00213-015-3927-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Accepted: 03/24/2015] [Indexed: 11/28/2022]
Abstract
RATIONALE The driving simulator provides a safe and controlled environment for testing driving behaviour efficiently. The question is whether it is sensitive to detect drug-induced effects. OBJECTIVE The primary aim of the current study was to investigate the sensitivity of the driving simulator for detecting drug effects. As a case in point, we investigated the dose-related effects of oral ∆(9)-tetrahydrocannabinol (THC), i.e. dronabinol, on simulator and on-the-road driving performance in equally demanding driving tasks. METHOD Twenty-four experienced driver participants were treated with dronabinol (Marinol®; 10 and 20 mg) and placebo. Dose-related effects of the drug on the ability to keep a vehicle in lane (weaving) and to follow the speed changes of a lead car (car following) were compared within subjects for on-the-road versus in-simulator driving. Additionally, the outcomes of equivalence testing to alcohol-induced effects were investigated. RESULTS Treatment effects found on weaving when driving in the simulator were comparable to treatment effects found when driving on the road. The effect after 10 mg dronabinol was however less strong in the simulator than on the road and inter-individual variance seemed higher in the simulator. There was, however, a differential treatment effect of dronabinol on reactions to speed changes of a lead car (car following) when driving on the road versus when driving in the simulator. CONCLUSION The driving simulator was proven to be sensitive for demonstrating dronabinol-induced effects particularly at higher doses. Treatment effects of dronabinol on weaving were comparable with driving on the road but inter-individual variability seemed higher in the simulator than on the road which may have potential effects on the clinical inferences made from simulator driving. Car following on the road and in the simulator were, however, not comparable.
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Affiliation(s)
- J. L. Veldstra
- Faculty of Behavioural and Social Sciences, University of Groningen, Grote Kruisstraat 2/1, 9712TS Groningen, The Netherlands
| | - W. M. Bosker
- Institut für Neurowissenschaften und Medizin (INM-4), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - D. de Waard
- Faculty of Behavioural and Social Sciences, University of Groningen, Grote Kruisstraat 2/1, 9712TS Groningen, The Netherlands
| | - J. G. Ramaekers
- Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6229 ER Maastricht, The Netherlands
| | - K. A. Brookhuis
- Faculty of Behavioural and Social Sciences, University of Groningen, Grote Kruisstraat 2/1, 9712TS Groningen, The Netherlands
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Leufkens TRM, Ramaekers JG, de Weerd AW, Riedel WJ, Vermeeren A. Residual effects of zopiclone 7.5 mg on highway driving performance in insomnia patients and healthy controls: a placebo controlled crossover study. Psychopharmacology (Berl) 2014; 231:2785-98. [PMID: 24458443 PMCID: PMC4072058 DOI: 10.1007/s00213-014-3447-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 01/07/2014] [Indexed: 11/11/2022]
Abstract
RATIONALE Residual effects of hypnotics on driving performance have been mainly determined in studies using a standardized driving test with healthy good sleepers. Responses to effects may differ, however, between insomniacs and healthy volunteers due to the underlying sleep disorder. In addition, a majority of insomniacs uses hypnotics chronically resulting in the development of tolerance to impairing effects. Impaired driving performance in healthy volunteers may then be an overestimation of the actual effects in insomniacs. OBJECTIVES The present study aims to compare the residual effects of zopiclone 7.5 mg on on-the-road driving performance of 16 middle-aged insomniacs chronically using hypnotics (chronic users), 16 middle-aged insomniacs not or infrequently using hypnotics (infrequent users), and 16 healthy, age matched, good sleepers (controls). METHODS The study was conducted according to a 3 × 2 double-blind, placebo controlled crossover design, with three groups and two treatment conditions. Treatments were single oral doses of zopiclone 7.5 mg and placebo administered at bedtime (2330 hours). Between 10 and 11 h after administration subjects performed a standardized highway driving test. RESULTS Zopiclone 7.5 mg significantly impaired on-the-road driving performance in both insomnia groups and healthy controls. The magnitude of impairment was significantly less in the chronic users group as compared with the controls. CONCLUSIONS The smaller magnitude of effects suggests that investigating residual effects of hypnotics in healthy volunteers may yield a minor overestimation of the actual effects in insomnia patients.
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Affiliation(s)
- T. R. M. Leufkens
- Division Information and Cognition, Department of Brain, Body and Behavior, Philips Group Innovation–Research, High Tech Campus 34, 5656 AE Eindhoven, The Netherlands
| | - J. G. Ramaekers
- Experimental Psychopharmacology Unit, Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - A. W. de Weerd
- Department of Clinical Neurophysiology and Sleep Centre SEIN, Zwolle, The Netherlands
| | - W. J. Riedel
- Experimental Psychopharmacology Unit, Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - A. Vermeeren
- Experimental Psychopharmacology Unit, Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
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28
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Leufkens TRM, Ramaekers JG, de Weerd AW, Riedel WJ, Vermeeren A. On-the-road driving performance and driving-related skills in older untreated insomnia patients and chronic users of hypnotics. Psychopharmacology (Berl) 2014; 231:2851-65. [PMID: 24488406 PMCID: PMC4072063 DOI: 10.1007/s00213-014-3455-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 01/13/2014] [Indexed: 12/04/2022]
Abstract
RATIONALE Many older adults report sleep problems and use of hypnotics. Several studies have shown that hypnotics can have acute adverse effects on driving the next morning. It is unclear however whether driving of chronic hypnotic users is impaired. Therapeutic effects on insomnia and development of tolerance may reduce the residual effects on driving. OBJECTIVES The present study aimed to compare actual driving performance and driving-related skills of chronic hypnotic users to good sleepers. To determine whether insomnia itself affects driving performance, driving and driving-related skills were compared between insomnia patients who do not or infrequently use hypnotics and good sleepers. METHODS Twenty-two frequent users of hypnotics (using hypnotics ≥ 4 nights per week for more than 3 months), 20 infrequent users (using hypnotics ≤ 3 nights per week), and 21 healthy, age-matched controls participated in this study. On the night before testing, all subjects were hospitalized for an 8-h sleep recorded by polysomnography. Frequent hypnotic users used their regular medication at bedtime (2330 hours), while infrequent users and controls received no medication. Cognitive performance (word learning, digit span, tracking, divided attention, vigilance, and inhibitory control) was assessed 8.5 h and driving performance between 10 and 11 h after bedtime and dosing. RESULTS Polysomnographic recordings did not significantly differ between the groups, but the insomnia patients, treated or untreated, still reported subjective sleep complaints. Results show no differences in driving performance and driving-related skills between both groups of insomnia patients and controls. CONCLUSIONS Driving performance in chronic users of hypnotics and untreated insomnia patients is not impaired. For chronic users, this may be due to prescription of relatively safe drugs and low doses. For untreated insomniacs, this corroborates previous findings showing an absence of neuropsychological deficits in this group of patients.
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Affiliation(s)
- T. R. M. Leufkens
- Philips Group Innovation–Research, Division Information and Cognition, Department of Brain, Body and Behavior, High Tech Campus 34, 5656 AE Eindhoven, The Netherlands
| | - J. G. Ramaekers
- Experimental Psychopharmacology Unit, Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - A. W. de Weerd
- Department of Clinical Neurophysiology and Sleep Centre SEIN, Zwolle, The Netherlands
| | - W. J. Riedel
- Experimental Psychopharmacology Unit, Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - A. Vermeeren
- Experimental Psychopharmacology Unit, Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
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van Wel JHP, Kuypers KPC, Theunissen EL, Toennes SW, Spronk DB, Verkes RJ, Ramaekers JG. Single doses of THC and cocaine decrease proficiency of impulse control in heavy cannabis users. Br J Pharmacol 2013; 170:1410-20. [PMID: 24106872 PMCID: PMC3838687 DOI: 10.1111/bph.12425] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 08/05/2013] [Accepted: 08/13/2013] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Cannabis is the most popular drug used in the European Union, closely followed by cocaine. Whereas cannabis impairs neurocognitive function in occasional cannabis users, such impairments appear less prominent in heavy users, possibly as a result of tolerance. The present study was designed to assess whether the impairing effects of Δ(9) -tetrahydrocannabinol (THC) in heavy cannabis users would present in a wide range of neuropsychological functions or selectively affect specific performance domains. We also assessed the acute effects of cocaine on neurocognitive functions of heavy cannabis users. EXPERIMENTAL APPROACH Heavy cannabis users, who had a history of cocaine use (n = 61), participated in a double-blind, placebo-controlled, three-way crossover study. Subjects received single doses of cocaine HCl (300 mg), cannabis (THC μg·kg(-1) ) and placebo, and completed a number of tests measuring impulse control and psychomotor function. KEY RESULTS Single doses of cannabis impaired psychomotor function and increased response errors during impulsivity tasks. Single doses of cocaine improved psychomotor function and decreased response time in impulsivity tasks, but increased errors. CONCLUSIONS AND IMPLICATIONS Heavy cannabis users display impairments in a broad range of neuropsychological domains during THC intoxication. Impairments observed in psychomotor tasks, but not in impulsivity tasks, appeared smaller in magnitude as compared with those previously reported in occasional cannabis users. Heavy cannabis users were sensitive to the stimulating and inhibitory effects of cocaine on psychomotor function and impulsivity respectively. The reduction in proficiency in impulse control may put drug users at increased risk of repeated drug use and addiction.
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Affiliation(s)
- J H P van Wel
- Department Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht UniversityMaastricht, The Netherlands
| | - K P C Kuypers
- Department Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht UniversityMaastricht, The Netherlands
| | - E L Theunissen
- Department Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht UniversityMaastricht, The Netherlands
| | - S W Toennes
- Department of Forensic Toxicology, Institute of Legal Medicine, Goethe University of FrankfurtFrankfurt, Germany
| | - D B Spronk
- Department of Psychiatry (966), Radboud University Nijmegen Medical CentreNijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University NijmegenNijmegen, The Netherlands
| | - R J Verkes
- Department of Psychiatry (966), Radboud University Nijmegen Medical CentreNijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University NijmegenNijmegen, The Netherlands
| | - J G Ramaekers
- Department Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht UniversityMaastricht, The Netherlands
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Ramaekers JG, Evers EA, Theunissen EL, Kuypers KPC, Goulas A, Stiers P. Methylphenidate reduces functional connectivity of nucleus accumbens in brain reward circuit. Psychopharmacology (Berl) 2013; 229:219-26. [PMID: 23604336 DOI: 10.1007/s00213-013-3105-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 03/27/2013] [Indexed: 11/26/2022]
Abstract
Release of dopamine in the nucleus accumbens (NAcc) is essential for acute drug reward. The present study was designed to trace the reinforcing effect of dopamine release by measuring the functional connectivity (FC) between the NAcc and brain regions involved in a limbic cortical-subcortical circuit during a dopaminergic challenge. Twenty healthy volunteers received single doses of methylphenidate (40 mg) and placebo on separate test days according to a double-blind, cross-over study design. Resting state functional magnetic resonance imaging (fMRI) was measured between 1.5 and 2 h postdosing. FC between regions of interest (ROI) in the NAcc, the medial dorsal nucleus (MDN) of the thalamus and remote areas within the limbic circuit was explored. Methylphenidate significantly reduced FC between the NAcc and the basal ganglia (i.e., subthalamic nucleus and ventral pallidum (VP)), relative to placebo. Methylphenidate also decreased FC between the NAcc and the medial prefrontal cortex (mPFC) as well as the temporal cortex. Methylphenidate did not affect FC between MDN and the limbic circuit. It is concluded that methylphenidate directly affects the limbic reward circuit. Drug-induced changes in FC of the NAcc may serve as a useful marker of drug activity in in the brain reward circuit.
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Affiliation(s)
- J G Ramaekers
- Department Neuropsychology & Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
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Kuypers KPC, de la Torre R, Farre M, Pujadas M, Ramaekers JG. Inhibition of MDMA-induced increase in cortisol does not prevent acute impairment of verbal memory. Br J Pharmacol 2013; 168:607-17. [PMID: 22946487 PMCID: PMC3579237 DOI: 10.1111/j.1476-5381.2012.02196.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 07/31/2012] [Accepted: 08/08/2012] [Indexed: 01/20/2023] Open
Abstract
Background Ecstasy use is commonly linked with memory deficits in abstinent ecstasy users. Similar impairments are being found during ecstasy intoxication after single doses of ± 3,4 metylenedioxymethamphetamine (MDMA). The concordance of memory impairments during intoxication and abstinence suggests a similar neuropharmacological mechanism underlying acute and chronic memory impairments. The mechanism underlying this impairment is to date not known. We hypothesized that cortisol might play an important role in this mechanism as cortisol, implicated in the regulation of memory performance, can be brought out of balance by stressors like MDMA. Methods In the present study, we aimed to block the MDMA-induced acute memory defect by giving participants a cortisol synthesis inhibitor (metyrapone) together with a single dose of MDMA. Seventeen polydrug MDMA users entered this placebo-controlled within subject study with four treatment conditions. The treatments consisted of MDMA (75 mg) and metyrapone (750 mg), alone and in combination, and double placebo. Pre-treatment with metyrapone or Placebo occurred 1 h prior to MDMA or Placebo administration. Memory performance was tested at peak drug concentrations by means of several memory tests. Cortisol levels were determined in blood and oral fluid; this served as a control measure to see whether manipulations were effective. Results Main findings indicated that whereas treatment with metyrapone blocked the expected MDMA-induced increase in cortisol levels in blood, it did not prevent the MDMA-induced memory deficit from happening. Conclusion We therefore conclude that MDMA-induced increments in cortisol concentrations are not related to MDMA-induced memory impairments.
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Affiliation(s)
- K P C Kuypers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, The Netherlands.
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Reneerkens OAH, Sambeth A, Ramaekers JG, Steinbusch HWM, Blokland A, Prickaerts J. The effects of the phosphodiesterase type 5 inhibitor vardenafil on cognitive performance in healthy adults: a behavioral-electroencephalography study. J Psychopharmacol 2013; 27:600-8. [PMID: 23427190 DOI: 10.1177/0269881113477747] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Phosphodiesterase type 5 inhibitors (PDE5-Is) improve cognitive performance of rodents, but the few human studies investigating their effects did not systematically investigate cognitive effects and the results have been quite contradictory. Therefore, we examined whether the PDE5-I vardenafil improves memory and executive functioning and affect electroencephalography (EEG) in healthy young adults. Participants were selected out of a group of volunteers, based on their performance on a memory screening and they were orally treated with vardenafil (10-20 mg or placebo). Memory and executive functioning were tested while EEG activity was recorded. Additionally, a simple reaction time task and questionnaires addressing various complaints were presented. No prominent effects of vardenafil on cognition were found: participants only made more mistakes on a reaction time task after 20 mg vardenafil. During encoding of words, the P300 was generally smaller after vardenafil treatment. Furthermore, the N400 was larger after vardenafil 10 mg than placebo treatment in a spatial memory task at Fz. Finally, headache and feeling weak were reported more after vardenafil treatment. Vardenafil did not affect cognitive performance of healthy adults and showed only some incidental effects on ERPs. These findings in humans do not corroborate the cognition-enhancing effects of PDE5-Is in healthy animals.
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Affiliation(s)
- O A H Reneerkens
- Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, the Netherlands
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Theunissen EL, Street D, Højer AM, Vermeeren A, van Oers A, Ramaekers JG. A Randomized Trial on the Acute and Steady-State Effects of a New Antidepressant, Vortioxetine (Lu AA21004), on Actual Driving and Cognition. Clin Pharmacol Ther 2013; 93:493-501. [DOI: 10.1038/clpt.2013.39] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Spronk DB, Veth CPM, Arns M, Schofield PR, Dobson-Stone C, Ramaekers JG, Franke B, de Bruijn ERA, Verkes RJ. DBH -1021C>T and COMT Val108/158Met genotype are not associated with the P300 ERP in an auditory oddball task. Clin Neurophysiol 2012; 124:909-15. [PMID: 23261162 DOI: 10.1016/j.clinph.2012.11.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 10/29/2012] [Accepted: 11/06/2012] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The amplitude and latency of the P300 may be associated by variations in dopaminergic genes. The current study was conducted to determine whether functional variants of the catechol-O-methyltransferase (COMT) and dopamine beta-hydroxylase (DBH) gene were associated with P300 amplitude and latency in an auditory oddball task. METHODS The P300 ERP was assessed by a two-tone auditory oddball paradigm in a large sample of 320 healthy volunteers. The Val108/158Met polymorphism (rs4680) of the COMT gene and the -1021C>T polymorphism (rs1611115) of the DBH gene were genotyped. P300 amplitude and latency were compared across genotype groups using analysis of variance. RESULTS There were no differences in demographic characteristics in subjects for genotypic subgroups. No genotype associations were observed for the P300 amplitude and latency on frontal, central and parietal electrode positions. CONCLUSIONS COMT Val108/158Met and DBH -1021C>T polymorphisms do not show evidence of association with characteristics of the P300 ERP in an auditory oddball paradigm in healthy volunteers. SIGNIFICANCE We failed to find evidence for the association between dopaminergic enzymatic polymorphisms and the P300 ERP in healthy volunteers, in the largest study undertaken to date.
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Affiliation(s)
- D B Spronk
- Department of Psychiatry (966), Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
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Bosker WM, Theunissen EL, Conen S, Kuypers KPC, Jeffery WK, Walls HC, Kauert GF, Toennes SW, Moeller MR, Ramaekers JG. A placebo-controlled study to assess Standardized Field Sobriety Tests performance during alcohol and cannabis intoxication in heavy cannabis users and accuracy of point of collection testing devices for detecting THC in oral fluid. Psychopharmacology (Berl) 2012; 223:439-46. [PMID: 22581391 PMCID: PMC3456923 DOI: 10.1007/s00213-012-2732-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Accepted: 04/23/2012] [Indexed: 11/27/2022]
Abstract
RATIONALE Standardized Field Sobriety Tests (SFST) and oral fluid devices are used to screen for driving impairment and roadside drug detection, respectively. SFST have been validated for alcohol, but their sensitivity to impairment induced by other drugs is relatively unknown. The sensitivity and specificity for Δ(9)-tetrahydrocannabinol (THC) of most oral fluid devices have been low. OBJECTIVE This study assessed the effects of smoking cannabis with and without alcohol on SFST performance. Presence of THC in oral fluid was examined with two devices (Dräger Drug Test® 5000 and Securetec Drugwipe® 5). METHODS Twenty heavy cannabis users (15 males and 5 females; mean age, 24.3 years) participated in a double-blind, placebo-controlled study assessing percentage of impaired individuals on the SFST and the sensitivity of two oral fluid devices. Participants received alcohol doses or alcohol placebo in combination with 400 μg/kg body weight THC. We aimed to reach peak blood alcohol concentration values of 0.5 and 0.7 mg/mL. RESULTS Cannabis was significantly related to performance on the one-leg stand (p = 0.037). Alcohol in combination with cannabis was significantly related to impairment on horizontal gaze nystagmus (p = 0.029). The Dräger Drug Test® 5000 demonstrated a high sensitivity for THC, whereas the sensitivity of the Securetec Drugwipe® 5 was low. CONCLUSIONS SFST were mildly sensitive to impairment from cannabis in heavy users. Lack of sensitivity might be attributed to tolerance and time of testing. SFST were sensitive to both doses of alcohol. The Dräger Drug Test® 5000 appears to be a promising tool for detecting THC in oral fluid as far as correct THC detection is concerned.
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Affiliation(s)
- W M Bosker
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
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Ramaekers JG, Kuypers KPC, Bosker WM, Brookhuis KA, Veldstra JA, Simons R, Martens M, Hjälmdahl M, Forsman Å, Knoche A. Effects of stimulant drugs on actual and simulated driving: perspectives from four experimental studies conducted as part of the DRUID research consortium. Psychopharmacology (Berl) 2012; 222:413-8. [PMID: 22700041 PMCID: PMC3395336 DOI: 10.1007/s00213-012-2766-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 05/28/2012] [Indexed: 12/04/2022]
Affiliation(s)
- J. G. Ramaekers
- Department Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - K. P. C. Kuypers
- Department Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - W. M. Bosker
- Department Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - K. A. Brookhuis
- University of Groningen, Groningen, The Netherlands ,Delft University of Technology, Delft, The Netherlands
| | | | - R. Simons
- TNO Human Factors, Soesterberg, The Netherlands
| | - M. Martens
- TNO Human Factors, Soesterberg, The Netherlands
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Toennes SW, Ramaekers JG, Theunissen EL, Moeller MR, Kauert GF. Pharmacokinetic Properties of 9-Tetrahydrocannabinol in Oral Fluid of Occasional and Chronic Users. J Anal Toxicol 2010; 34:216-21. [DOI: 10.1093/jat/34.4.216] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Boy RG, Henseler J, Ramaekers JG, Mattern R, Skopp G. A Comparison Between Experimental and Authentic Blood/Serum Ratios of 3,4-Methylenedioxymethamphetamine and 3,4-Methylenedioxyamphetamine. J Anal Toxicol 2009; 33:283-6. [DOI: 10.1093/jat/33.5.283] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ramaekers JG, Kauert G, Theunissen EL, Toennes SW, Moeller MR. Neurocognitive performance during acute THC intoxication in heavy and occasional cannabis users. J Psychopharmacol 2009; 23:266-77. [PMID: 18719045 DOI: 10.1177/0269881108092393] [Citation(s) in RCA: 231] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Performance impairment during Delta(9)-tetrahydrocannabinol (THC) intoxication has been well described in occasional cannabis users. It is less clear whether tolerance develops to the impairing effects of THC in heavy users of cannabis. The aim of the present study was to assess neurocognitive performance during acute THC intoxication in occasional and heavy users. Twenty-four subjects (12 occasional cannabis users and 12 heavy cannabis users) participated in a double-blind, placebo-controlled, two-way mixed model design. Both groups received single doses of THC placebo and 500 microg/kg THC by smoking. Performance tests were conducted at regular intervals between 0 and 8 h after smoking, and included measures of perceptual motor control (critical tracking task), dual task processing (divided attention task), motor inhibition (stop signal task) and cognition (Tower of London). THC significantly impaired performance of occasional cannabis users on critical tracking, divided attention and the stop signal task. THC did not affect the performance of heavy cannabis users except in the stop signal task, i.e. stop reaction time increased, particularly at high THC concentrations. Group comparisons of overall performance in occasional and heavy users did not reveal any persistent performance differences due to residual THC in heavy users. These data indicate that cannabis use history strongly determines the behavioural response to single doses of THC.
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Affiliation(s)
- J G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology, Maastricht University, Maastricht, The Netherlands.
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Abstract
Previously it has been shown that MDMA causes memory impairment during daytime testing. However, MDMA is usually taken in the evening or during the night. In addition, it is known that sleep deprivation also causes memory impairment. The present study aimed to assess whether evening doses of MDMA added to, or interacted with the memory impairment due to sleep deprivation. Fourteen healthy subjects participated in a double-blind, placebo-controlled, two-way cross-over study. Treatments consisted of MDMA 75 and 50 mg divided over the evening or double placebo. Memory tests and subjective measures of mood were conducted at baseline and three times post dosing that is at 6.30 pm, 9.30 pm, 1.30 am and 7 am, respectively -1.5, 1.5, 5.5 and 11 h relative to drug intake (first dose). Memory performance detoriated progessively over time as a function of sleep loss, independent of treatment. MDMA added to this impairment as indicated by a significant main effect of MDMA on verbal and spatial memory performance. Mood ratings and response speed revealed an MDMA by Time interaction. After administration of MDMA response speed improved and feelings of vigor, friendliness, elation, anxiety, confusion, arousal and positive mood increased in magnitude during the night, while all these parameters returned to placebo-like levels on the final morning session. It is concluded that evening doses of MDMA selectively impair memory performance, and that this impairment is additional to the effect of sleep deprivation on memory performance.
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Affiliation(s)
- K P C Kuypers
- Experimental Psychopharmacology Unit, Department of Neuropsychology and Psychopharmacology, Faculty of Psychology, Maastricht University, Maastricht, The Netherlands.
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Toennes SW, Ramaekers JG, Theunissen EL, Moeller MR, Kauert GF. Comparison of Cannabinoid Pharmacokinetic Properties in Occasional and Heavy Users Smoking a Marijuana or Placebo Joint. J Anal Toxicol 2008; 32:470-7. [DOI: 10.1093/jat/32.7.470] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Wingen M, Kuypers KPC, Ramaekers JG. Selective verbal and spatial memory impairment after 5-HT1A and 5-HT2A receptor blockade in healthy volunteers pre-treated with an SSRI. J Psychopharmacol 2007; 21:477-85. [PMID: 17092965 DOI: 10.1177/0269881106072506] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Serotonergic neurotransmission has been implicated in memory impairment. It is unclear however if memory performance is mediated through general 5-HT availability, through specific 5-HT receptors or both. The aim of the present study was to assess the contribution of 5-HT reuptake inhibition and specific blockade of 5-HT(1A) and 5-HT(2A) receptors to memory impairment. The study was conducted according to a randomized, double-blind, placebo-controlled, four-way cross-over design including 16 healthy volunteers. The treatment consisted of oral administration of escitalopram 20 mg + placebo, escitalopram 20 mg + ketanserin 50 mg, escitalopram 20 mg + pindolol 10 mg and placebo on 4 separate days with a washout period of minimum 7 days. Different memory tasks were performed including verbal memory, spatial working memory and reversal learning. Escitalopram showed an impairing effect on immediate verbal recall which nearly reached statistical significance. No effects of escitalopram were found on other types of memory. In combination with pindolol, immediate verbal recall was significantly impaired. Escitalopram in combination with ketanserin impaired spatial working memory significantly. No effects were found on reversal learning. Selective impairment of immediate verbal recall after a 5-HT(1A) partial agonist and selective impairment of spatial working memory performance after 5-HT(2A) receptor antagonist, both in combination with a selective serotonergic reuptake inhibitor (escitalopram), suggests that 5-HT(1A) and 5-HT(2A) receptors are distinctly involved in verbal and spatial memory.
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Affiliation(s)
- M Wingen
- Experimental Psychopharmacology Unit, Faculty of Psychology, Brain & Behaviour Institute, Maastricht University, The Netherlands.
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Kuypers KPC, Wingen M, Samyn N, Limbert N, Ramaekers JG. Acute effects of nocturnal doses of MDMA on measures of impulsivity and psychomotor performance throughout the night. Psychopharmacology (Berl) 2007; 192:111-9. [PMID: 17219216 DOI: 10.1007/s00213-006-0679-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Accepted: 12/13/2006] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Previous studies on the acute effects of MDMA on psychomotor performance and impulsivity showed that MDMA acts as a stimulant. These studies assessed performance during daytime, whereas in real life, dance-attendees leaving a party use the drug during the night. OBJECTIVES The present study aimed to assess the effects of nocturnal doses of MDMA on psychomotor performance and impulsivity during the night and after a night of sleep deprivation. MATERIALS AND METHODS Fourteen healthy subjects participated in a double-blind, placebo-controlled, two-way within-subject study. The treatment was MDMA (75 and 50 mg) divided over the evening or double placebo. Psychomotor and impulsivity tasks were conducted four times throughout the evening and night. A vigilance test was conducted once, at 5 A.M.,: and a sleepiness scale was presented to the subjects ten times throughout the evening and night. RESULTS MDMA impaired tracking performance in a simple tracking task. Divided attention task performance was also impaired as indicated by a decrease in secondary task performance under the influence of MDMA compared with placebo. MDMA did not affect impulsivity measures. Vigilance performance decreased as a function of time on task, but this decrement was less during MDMA treatment compared to placebo. After the administration of MDMA, the sleepiness scale scores were lower during the night when compared with placebo. This difference between MDMA and placebo disappeared in the morning. CONCLUSION It is concluded that nocturnal doses of MDMA may produce impairments of tracking performance and divided attention throughout the night that are additive to performance impairment produced by sleep loss.
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Affiliation(s)
- K P C Kuypers
- Experimental Psychopharmacology Unit, Department of Neurocognition, Faculty of Psychology, Maastricht University, Maastricht, The Netherlands.
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Ramaekers JG, Moeller MR, van Ruitenbeek P, Theunissen EL, Schneider E, Kauert G. Cognition and motor control as a function of Delta9-THC concentration in serum and oral fluid: limits of impairment. Drug Alcohol Depend 2006; 85:114-22. [PMID: 16723194 DOI: 10.1016/j.drugalcdep.2006.03.015] [Citation(s) in RCA: 204] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Revised: 03/22/2006] [Accepted: 03/23/2006] [Indexed: 11/20/2022]
Abstract
Cannabis use has been associated with increased risk of becoming involved in traffic accidents; however, the relation between THC concentration and driver impairment is relatively obscure. The present study was designed to define performance impairment as a function of THC in serum and oral fluid in order to provide a scientific framework to the development of per se limits for driving under the influence of cannabis. Twenty recreational users of cannabis participated in a double-blind, placebo-controlled, three-way cross-over study. Subjects were administered single doses of 0, 250 and 500 microg/kg THC by smoking. Performance tests measuring skills related to driving were conducted at regular intervals between 15 min and 6h post smoking and included measures of perceptual-motor control (Critical tracking task), motor impulsivity (Stop signal task) and cognitive function (Tower of London). Blood and oral fluid were collected throughout testing. Results showed a strong and linear relation between THC in serum and oral fluid. Linear relations between magnitude of performance impairment and THC in oral fluid and serum, however, were low. A more promising way to define threshold levels of impairment was found by comparing the proportion of observations showing impairment or no impairment as a function of THC concentration. The proportion of observations showing impairment progressively increased as a function of serum THC in every task. Binomial tests showed an initial and significant shift toward impairment in the Critical tracking task for serum THC concentrations between 2 and 5 ng/ml. At concentrations between 5 and 10 ng/ml approximately 75-90% of the observations were indicative of significant impairment in every performance test. At THC concentrations >30 ng/ml the proportion of observations indicative of significant impairment increased to a full 100% in every performance tests. It is concluded that serum THC concentrations between 2 and 5 ng/ml establish the lower and upper range of a THC limit for impairment.
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Affiliation(s)
- J G Ramaekers
- Experimental Psychopharmacology Unit, Department of Neurocognition, Faculty of Psychology, Maastricht University, 6200 MD Maastricht, The Netherlands.
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Ramaekers JG, Kuypers KPC, Samyn N. Stimulant effects of 3,4-methylenedioxymethamphetamine (MDMA) 75 mg and methylphenidate 20 mg on actual driving during intoxication and withdrawal. Addiction 2006; 101:1614-21. [PMID: 17034441 DOI: 10.1111/j.1360-0443.2006.01566.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND 3,4-methylenedioxymethamphetamine (MDMA) is currently one of the most popular drugs of abuse in Europe. Its increasing use over the last decade has led to concern regarding possible adverse effects on driving. The aims of the present study were to investigate the acute effects of MDMA on actual driving performance during the intoxication and withdrawal phase. METHODS Eighteen recreational MDMA-users (nine males, nine females) aged 21-39 years participated in a double-blind, placebo-controlled, three-way cross-over study. MDMA 75 mg, methylphenidate 20 mg and placebo were administered on day 1 of treatment (intoxication phase). Driving tests were conducted between 3 and 5 hours post-drug. Subjects returned the following day for a repetition of the driving tests between 27 and 29 hours post-drug (withdrawal phase). On-the-road driving tests consisted of a road-tracking test and a car-following test. Its main parameters were standard deviation of lateral position (SDLP), time to speed adaptation (TSA), brake reaction time (BRT) and gain. FINDINGS MDMA and methylphenidate significantly decreased SDLP in the road-tracking tests by about 2 cm relative to placebo on day 1 (intoxication phase). In addition, MDMA intoxication decreased performance in the car-following test as indicated by a significant rise in the 'overshoot' of the subjects' response to speed decelerations of the leading vehicle. Driving performance was not affected by treatments during withdrawal on day 2. CONCLUSION Collectively, these data indicate that MDMA is a stimulant drug that may improve certain aspects of the driving task, such as road-tracking performance, but may reduce performance in other aspects of the driving task, such as accuracy of speed adaptation during car-following performance.
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Affiliation(s)
- J G Ramaekers
- Experimental Psychopharmacology Unit, Department of Neurocognition, Faculty of Psychology, Maastricht University, the Netherlands.
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Wingen M, Langer S, Ramaekers JG. Verbal memory performance during subchronic challenge with a selective serotonergic and a mixed action antidepressant. Hum Psychopharmacol 2006; 21:473-9. [PMID: 17029307 DOI: 10.1002/hup.800] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVES Effects of escitalopram 10-20 mg/day and mirtazapine 30-45 mg/day on verbal memory of 18 healthy participants were assessed in a randomized, double-blind, placebo-controlled, three-way crossover trial. METHOD Each treatment period lasted for 15 days and was separated from the next period by a washout period of at least 13 days. Participants received an evening dose of escitalopram 10 mg, mirtazapine 30 mg, or placebo from days 1 to 7 and an evening dose of escitalopram 20 mg, mirtazapine 45 mg, or placebo from days 8 to 15. On days 2, 9, and 16 a visual verbal memory task was performed measuring drug effects during the acute phase, after dose increase and at steady state. RESULTS Escitalopram did not affect immediate or delayed verbal memory score throughout treatment. During mirtazapine treatment, participants performed less well in the overall immediate recall score compared to placebo. This impairment was most pronounced in the final trial of the visual verbal learning task. CONCLUSION Verbal memory was not affected by acute and subchronic escitalopram treatment in healthy participants. Overall immediate verbal memory was slightly but significantly impaired throughout mirtazapine treatment, probably due to a general reduction in overall arousal caused by H1 blockade.
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Affiliation(s)
- M Wingen
- Experimental Psychopharmacology Unit, Faculty of Psychology, University of Maastricht, The Netherlands.
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Kuypers KPC, Samyn N, Ramaekers JG. MDMA and alcohol effects, combined and alone, on objective and subjective measures of actual driving performance and psychomotor function. Psychopharmacology (Berl) 2006; 187:467-75. [PMID: 16830130 DOI: 10.1007/s00213-006-0434-z] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Accepted: 05/10/2006] [Indexed: 10/24/2022]
Abstract
RATIONALE The party drug ecstasy is frequently used in combination with other drugs like marihuana and alcohol. In addition, a substantial proportion of the MDMA users has claimed to drive a car when under the influence of MDMA and/or other drugs. OBJECTIVE To assess the effects of MDMA and alcohol, combined and alone, on actual driving performance and laboratory tasks related to driving. METHODS Eighteen healthy subjects participated in a double-blind, placebo-controlled, six-way cross-over study. Treatments consisted of MDMA 0, 75, and 100 mg with and without alcohol, aiming at 0.06 mg/ml BAC. Laboratory tests (critical tracking task, object movement estimation task) were conducted between 1.5 and 2 h postdrug (0.5 and 1 h postalcohol). Actual driving tests (road tracking test, car-following test) were conducted between 3 and 5 h postdrug (2 and 4 h postalcohol). Subjects completed the addiction research center inventory (ARCI) and rated their driving quality and mental effort during driving. RESULTS Alcohol alone impaired critical tracking performance, as well as a number of actual driving performance parameters [i.e., standard deviation of lateral position (SDLP), brake reaction time, and coherence]. MDMA alone reduced SDLP and standard deviation of speed. MDMA significantly moderated alcohol induced impairment of road tracking performance but did not affect alcohol impairments of car-following and laboratory task performance. Subjective data seemed to support objective data. CONCLUSION MDMA moderated the impairing effects of a low dose of alcohol on road tracking performance but it could not overcome alcohol-induced impairment on other aspects of driving behavior or driving related performance.
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Affiliation(s)
- K P C Kuypers
- Experimental Psychopharmacology Unit, Department of Neurocognition, Faculty of Psychology, Maastricht University, Maastricht, The Netherlands.
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Abstract
In the past decade, experimental studies involving healthy human volunteers have revealed that manipulations of the central serotonin (5-HT) system can produce quite specific changes in cognitive functioning, independent of overt mood changes. Reduced 5-HT turnover is consistently associated with impaired long-term memory functioning. Low 5-HT function may also impair cognitive flexibility and improve focused attention. On the other hand, stimulation of central 5-HT has repeatedly been found to impair performance in a true vigilance task. Currently, there is little evidence for mirrored cognitive changes due to opposite 5-HT manipulations in healthy volunteers. Given the mounting evidence for a role of 5-HT in human cognition, reduced 5-HT function could be directly linked to cognitive disturbances in certain conditions, such as in depression and Alzheimer's Disease (AD). There is evidence that stimulating (i.e. normalizing) 5-HT activity in depression may have specific beneficial effects on cognition, independent of a general relief of depressive symptoms, but this premise needs to be confirmed by larger-scale clinical studies. Recently, a potential role of 5-HT in the cognitive symptoms in AD has been identified, but there is insufficient data to evaluate the effects of 5-HT stimulation on cognitive symptoms in AD. It is concluded that serotonin is a potential target for pharmacological cognition enhancement, particularly for restoration of impaired cognitive performance due to 5-HT dysfunction. Further differentiation of the role of 5-HT in normal and disturbed cognition and evaluation of the effects of 5-HT manipulations in various populations is required to establish the full potential of 5-HT drugs as cognition enhancers.
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Affiliation(s)
- J A J Schmitt
- Nestlé Research Center, Nutrition and Health Department, Lausanne, Switzerland.
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Berghaus G, Ramaekers JG, Drummer OH. Demands on scientific studies in different fields of forensic medicine and forensic sciences. Traffic medicine--impaired driver: alcohol, drugs, diseases. Forensic Sci Int 2006; 165:233-7. [PMID: 16793231 DOI: 10.1016/j.forsciint.2006.05.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Revised: 03/13/2006] [Accepted: 05/10/2006] [Indexed: 10/24/2022]
Abstract
Since human performance is a key factor in crash causation detailed knowledge of the involvement of alcohol, drugs and diseases is of fundamental interest for road safety. To better understand the effect of these influencing factors it is important to use a combination of witness observations and a range of experimental and epidemiological studies. Epidemiological approaches to research such as road-side-surveys, case-control-studies, culpability analysis, pharmaco-epidemiological studies are usually seen as being able to provide the best answers. This article discusses the relative merits of experimental and epidemiological approaches.
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Affiliation(s)
- G Berghaus
- Institute of Legal Medicine, University of Cologne, Melatengürtel 60-62, 50823 Köln, Germany.
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Abstract
Repeated ecstasy (MDMA) use is reported to impair cognition and cause increased feelings of depression and anxiety. Yet, many relevant studies have failed to control for use of drugs other than MDMA, especially marijuana (THC). To address these confounding effects we compared behavioural performance of 11 MDMA/THC users, 15 THC users and 15 non-drug users matched for age and intellect. We tested the hypothesis that reported feelings of depression and anxiety and cognitive impairment (memory, executive function and decision making) are more severe in MDMA/THC users than in THC users. MDMA/THC users reported more intense feelings of depression and anxiety than THC users and non-drug users. Memory function was impaired in both groups of drug users. MDMA/THC users showed slower psychomotor speed and less mental flexibility than non-drug users. THC users exhibited less mental flexibility and performed worse on the decision making task compared to non-drug users but these functions were similar to those in MDMA/THC users. It was concluded that MDMA use is associated with increased feelings of depression and anxiety compared to THC users and non-drug users. THC users were impaired in some cognitive abilities to the same degree as MDMA/THC users, suggesting that some cognitive impairment attributed to MDMA is more likely due to concurrent THC use.
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Affiliation(s)
- C T J Lamers
- Experimental Psychopharmacology Unit, Department of Neurocognition, Brain and Behaviour Institute, Maastricht University, The Netherlands
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