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Berger C, Müller-Godeffroy J, Marx I, Reis O, Buchmann J, Dück A. Methylphenidate promotes the interaction between motor cortex facilitation and attention in healthy adults: A combined study using event-related potentials and transcranial magnetic stimulation. Brain Behav 2018; 8:e01155. [PMID: 30417982 PMCID: PMC6305964 DOI: 10.1002/brb3.1155] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/27/2018] [Accepted: 10/14/2018] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE This study investigated simultaneously the impact of methylphenidate (MPH) on the interaction of inhibitory and facilitative pathways in regions processing motor and cognitive functions. METHOD Neural markers of attention and response control (event-related potentials) and motor cortical excitability (transcranial magnetic stimulation) and their pharmacological modulation by MPH were measured simultaneously in a sample of healthy adults (n = 31) performing a cued choice reaction test. RESULTS Methylphenidate modulated attentional gating and response preparation processes (increased contingent negative variation) and response inhibition (increased nogo P3). N1, cue- and go-P3 were not affected by MPH. Motor cortex facilitation, measured with long-interval cortical facilitation, was increased under MPH in the nogo condition and was positively correlated with the P3 amplitude. CONCLUSION Methylphenidate seems particularly to enhance response preparation processes. The MPH-induced increased motor cortex facilitation during inhibitory task demands was accompanied by increased terminal response inhibition control, probably as a compensatory process.
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Affiliation(s)
- Christoph Berger
- Department of Psychiatry, Neurology, Psychosomatics, Psychotherapy in Childhood and Adolescence, University Medical Center of Rostock, Rostock, Germany
| | - Juliane Müller-Godeffroy
- Department of Psychiatry, Neurology, Psychosomatics, Psychotherapy in Childhood and Adolescence, University Medical Center of Rostock, Rostock, Germany
| | - Ivo Marx
- Department of Psychiatry, Neurology, Psychosomatics, Psychotherapy in Childhood and Adolescence, University Medical Center of Rostock, Rostock, Germany
| | - Olaf Reis
- Department of Psychiatry, Neurology, Psychosomatics, Psychotherapy in Childhood and Adolescence, University Medical Center of Rostock, Rostock, Germany
| | - Johannes Buchmann
- Department of Psychiatry, Neurology, Psychosomatics, Psychotherapy in Childhood and Adolescence, University Medical Center of Rostock, Rostock, Germany
| | - Alexander Dück
- Department of Psychiatry, Neurology, Psychosomatics, Psychotherapy in Childhood and Adolescence, University Medical Center of Rostock, Rostock, Germany
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Ripollés P, Ferreri L, Mas-Herrero E, Alicart H, Gómez-Andrés A, Marco-Pallares J, Antonijoan RM, Noesselt T, Valle M, Riba J, Rodriguez-Fornells A. Intrinsically regulated learning is modulated by synaptic dopamine signaling. eLife 2018; 7:e38113. [PMID: 30160651 PMCID: PMC6133552 DOI: 10.7554/elife.38113] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 08/29/2018] [Indexed: 12/13/2022] Open
Abstract
We recently provided evidence that an intrinsic reward-related signal-triggered by successful learning in absence of any external feedback-modulated the entrance of new information into long-term memory via the activation of the dopaminergic midbrain, hippocampus, and ventral striatum (the SN/VTA-Hippocampal loop; Ripollés et al., 2016). Here, we used a double-blind, within-subject randomized pharmacological intervention to test whether this learning process is indeed dopamine-dependent. A group of healthy individuals completed three behavioral sessions of a language-learning task after the intake of different pharmacological treatments: a dopaminergic precursor, a dopamine receptor antagonist or a placebo. Results show that the pharmacological intervention modulated behavioral measures of both learning and pleasantness, inducing memory benefits after 24 hr only for those participants with a high sensitivity to reward. These results provide causal evidence for a dopamine-dependent mechanism instrumental in intrinsically regulated learning and further suggest that subject-specific reward sensitivity drastically alters learning success.
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Affiliation(s)
- Pablo Ripollés
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute- IDIBELLL’Hospitalet de LlobregatBarcelonaSpain
- Department of Cognition, Development and Educational PsychologyCampus Bellvitge, University of Barcelona, L’Hospitalet de LlobregatBarcelonaSpain
- Department of PsychologyNew York UniversityNew YorkUnited States
| | - Laura Ferreri
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute- IDIBELLL’Hospitalet de LlobregatBarcelonaSpain
- Department of Cognition, Development and Educational PsychologyCampus Bellvitge, University of Barcelona, L’Hospitalet de LlobregatBarcelonaSpain
| | - Ernest Mas-Herrero
- Montreal Neurological InstituteMcGill UniversityMontrealCanada
- International Laboratory for Brain, Music, and Sound ResearchMontrealQCCanada
- Centre for Research on Brain, Language and MusicMontrealCanada
| | - Helena Alicart
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute- IDIBELLL’Hospitalet de LlobregatBarcelonaSpain
| | - Alba Gómez-Andrés
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute- IDIBELLL’Hospitalet de LlobregatBarcelonaSpain
| | - Josep Marco-Pallares
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute- IDIBELLL’Hospitalet de LlobregatBarcelonaSpain
- Department of Cognition, Development and Educational PsychologyCampus Bellvitge, University of Barcelona, L’Hospitalet de LlobregatBarcelonaSpain
| | - Rosa Maria Antonijoan
- Department of Pharmacology and TherapeuticsUniversitat Autònoma de BarcelonaBarcelonaSpain
- Centre d’Investigació de MedicamentsServei de Farmacologia Clínica, Hospital de la Santa Creu i Sant PauBarcelonaSpain
| | - Toemme Noesselt
- Department of NeurologyOtto-von-Guericke University, Leipziger StraßeMagdeburgGermany
- Department of Biological PsychologyOtto-von-Guericke-University Magdeburg, PostfachMagdeburgGermany
- Center for Behavioral Brain SciencesMagdeburgGermany
| | - Marta Valle
- Department of Pharmacology and TherapeuticsUniversitat Autònoma de BarcelonaBarcelonaSpain
- Pharmacokinetic/Pharmacodynamic Modeling and Simulation GroupSant Pau Institute of Biomedical ResearchBarcelonaSpain
| | - Jordi Riba
- Human Neuropsychopharmacology GroupSant Pau Institute of Biomedical ResearchBarcelonaSpain
| | - Antoni Rodriguez-Fornells
- Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute- IDIBELLL’Hospitalet de LlobregatBarcelonaSpain
- Department of Cognition, Development and Educational PsychologyCampus Bellvitge, University of Barcelona, L’Hospitalet de LlobregatBarcelonaSpain
- Catalan Institution for Research and Advanced StudiesBarcelonaSpain
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Hutten NRPW, Kuypers KPC, van Wel JHP, Theunissen EL, Toennes SW, Verkes RJ, Ramaekers JG. A single dose of cocaine enhances prospective memory performance. J Psychopharmacol 2018; 32:883-892. [PMID: 29947572 PMCID: PMC6058404 DOI: 10.1177/0269881118783299] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND Prospective memory is the ability to recall intended actions or events at the right time or in the right context. While cannabis is known to impair prospective memory, the acute effect of cocaine is unknown. In addition, it is not clear whether changes in prospective memory represent specific alterations in memory processing or result from more general effects on cognition that spread across multiple domains such as arousal and attention. AIMS The main objective of the study was, therefore, to determine whether drug-induced changes in prospective memory are memory specific or associated with more general drug-induced changes in attention and arousal. METHODS A placebo-controlled, three-way, cross-over study including 15 regular poly-drug users was set up to test the influence of oral cocaine (300 mg) and vaporised cannabis (300+150 'booster' µg/kg bodyweight) on an event-based prospective memory task. Attentional performance was assessed using a divided attention task and subjective arousal was assessed with the Profile of Mood States questionnaire. RESULTS Results showed that cocaine enhanced prospective memory, attention and arousal. Mean performance of prospective memory and attention, as well as levels of arousal were lowest during treatment with cannabis as compared with placebo and cocaine as evinced by a significantly increased trend across treatment conditions. Prospective memory performance was only weakly positively associated to measures of attention and arousal. CONCLUSION Together, these results indicate that cocaine enhancement of prospective memory performance cannot be fully explained by parallel changes in arousal and attention levels, and is likely to represent a direct change in the neural network underlying prospective memory.
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Affiliation(s)
- Nadia RPW Hutten
- Department of Neuropsychology and Psychopharmacology, Maastricht University, The Netherlands,Nadia RPW Hutten, Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, Maastricht 6200MD, The Netherlands.
| | - Kim PC Kuypers
- Department of Neuropsychology and Psychopharmacology, Maastricht University, The Netherlands
| | - Janelle HP van Wel
- Department of Neuropsychology and Psychopharmacology, Maastricht University, The Netherlands
| | - Eef L Theunissen
- Department of Neuropsychology and Psychopharmacology, Maastricht University, The Netherlands
| | - Stefan W Toennes
- Department of Forensic Toxicology, Goethe University of Frankfurt, Germany
| | - Robbert-Jan Verkes
- Department of Psychiatry, Radboud University Nijmegen Medical Centre, The Netherlands,Cognition and Behaviour, Donders Institute for Brain, Radboud University Nijmegen, The Netherlands
| | - Johannes G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Maastricht University, The Netherlands
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Martin C, Fricke D, Vijayashanthar A, Lowinger C, Koutsomitis D, Popoola D, Hadjiargyrou M, Komatsu DE, Thanos PK. Recovery from behavior and developmental effects of chronic oral methylphenidate following an abstinence period. Pharmacol Biochem Behav 2018; 172:22-32. [PMID: 30030127 DOI: 10.1016/j.pbb.2018.07.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 05/11/2018] [Accepted: 07/09/2018] [Indexed: 01/21/2023]
Abstract
Chronic oral methylphenidate (MP) exposure in rats is associated with numerous developmental and behavioral consequences. The present study investigated the persistence of the effects of chronic oral MP exposure after abstinence from MP use. Male and female rats were exposed to daily orally self-administered water, low dose MP (LD), or high dose (HD) MP for 13 weeks, followed by a 4-week abstinence period. Fluid, food consumption and bodyweights were monitored and animals were tested for locomotor activity, anxiety- and depressive-like symptoms, learning and memory, and social behavior during both the treatment and abstinence phases of the experiment. During treatment, MP attenuated bodyweight regardless of sex, but increased food and fluid consumption in females and males by 20.7% and 30.1%, respectively. MP also increased locomotor activity in both males and females observed as increased distance travelled in an open field. (59.1% and 95.9%, respectively) and increased locomotor activity in the home cage over a 24-hour circadian cycle (45.5% and 63.0%). Additionally, MP exerted an anxiolytic effect observed as increased time spent in the open arms of an elevated plus maze (31.1% in HD males, 59.2% in HD females), and an increased latency to immobility in a forced swim test (330% in HD males, 418% in HD females). The effects of MP (bodyweight, consumption, locomotion, anxiolytic, and anti-depressive) were, almost without exception, eliminated during the abstinence period. MP had no impact on learning and memory performance as measured by a T-maze, or social behavior during treatment. These findings suggest that the behavioral consequences of chronic oral MP treatment in our preclinical model are reversible in rats following an abstinence period from use of the drug.
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Affiliation(s)
- Connor Martin
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Research Institute on Addictions, Department of Pharmacology & Toxicology, Jacobs School of Medicine and Biosciences, University at Buffalo, Buffalo, NY, USA
| | - Dennis Fricke
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Research Institute on Addictions, Department of Pharmacology & Toxicology, Jacobs School of Medicine and Biosciences, University at Buffalo, Buffalo, NY, USA
| | - Abisha Vijayashanthar
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Research Institute on Addictions, Department of Pharmacology & Toxicology, Jacobs School of Medicine and Biosciences, University at Buffalo, Buffalo, NY, USA
| | - Courtney Lowinger
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Research Institute on Addictions, Department of Pharmacology & Toxicology, Jacobs School of Medicine and Biosciences, University at Buffalo, Buffalo, NY, USA
| | - Dimitris Koutsomitis
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Research Institute on Addictions, Department of Pharmacology & Toxicology, Jacobs School of Medicine and Biosciences, University at Buffalo, Buffalo, NY, USA
| | - Daniel Popoola
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Research Institute on Addictions, Department of Pharmacology & Toxicology, Jacobs School of Medicine and Biosciences, University at Buffalo, Buffalo, NY, USA
| | - Michael Hadjiargyrou
- New York Institute of Technology, Department of Life Sciences, Old Westbury, NY, USA
| | - David E Komatsu
- Stony Brook University, Department of Orthopedics, Stony Brook, NY, USA
| | - Panayotis K Thanos
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Research Institute on Addictions, Department of Pharmacology & Toxicology, Jacobs School of Medicine and Biosciences, University at Buffalo, Buffalo, NY, USA.
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Amphetamine improves mouse and human attention in the 5-choice continuous performance test. Neuropharmacology 2018; 138:87-96. [PMID: 29859849 DOI: 10.1016/j.neuropharm.2018.05.034] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 05/19/2018] [Accepted: 05/30/2018] [Indexed: 12/18/2022]
Abstract
Non-medical use of prescription stimulants amongst college students is common, with claims of cognitive and academic benefits. The mechanism, magnitude, and pervasiveness of the cognitive enhancing effects of stimulants in healthy adults remain poorly understood however. The present study determined the effects of dextroamphetamine (D-amp) on the 5-choice continuous performance test (5C-CPT) of attention in healthy young adult humans and mice. A mixed gender sample received placebo (n = 29), 10 (n = 17) or 20 mg D-amp (n = 25) in a double-blind fashion before 5C-CPT testing. In addition, male C57BL/6J mice were trained on a touchscreen adaptation of the 5C-CPT and tested after receiving saline or D-amp (0.1, 0.3, 1.0 mg/kg; n = 8/dose). In humans, D-amp significantly improved 5C-CPT performance. Both doses improved signal detection driven by increased hit rate (reduced omissions). Both doses also improved response accuracy and reduced hit reaction time (HRT) variability. In mice, similar effects (improved signal detection, hit rate, and response accuracy) were observed at the moderate dose (0.3 mg/kg). In contrast to human participants however, no effect on HRT variability was detected in mice, with no effect on HRT in either species. Human 5C-CPT performance was consistent with prior studies and consistent with alternative CPT paradigms. The performance of C57BL/6J mice on the touchscreen 5C-CPT mirrored performance of this strain on 5-hole operant chambers. Importantly, comparable facilitation of attention with D-amp was observed in both species. The 5C-CPT provides a cross-species paradigm by which the cognitive enhancing properties of stimulants and the neural underpinnings of attention can be assessed.
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Cotter J, Muhlert N, Talwar A, Granger K. Examining the effectiveness of acetylcholinesterase inhibitors and stimulant-based medications for cognitive dysfunction in multiple sclerosis: A systematic review and meta-analysis. Neurosci Biobehav Rev 2018; 86:99-107. [DOI: 10.1016/j.neubiorev.2018.01.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 12/09/2017] [Accepted: 01/18/2018] [Indexed: 11/29/2022]
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Klinge C, Shuttleworth C, Muglia P, Nobre AC, Harmer CJ, Murphy SE. Methylphenidate enhances implicit learning in healthy adults. J Psychopharmacol 2018; 32:70-80. [PMID: 28946787 DOI: 10.1177/0269881117731472] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND AND PURPOSE One limiting factor in the development of pharmacological interventions to enhance cognition is the absence of biomarkers that can be used in healthy volunteers to screen novel compounds. Drug discovery has tended to rely heavily on explicit measures of cognition, but these are typically insensitive to cognition-enhancing effects in healthy volunteers. This study investigated whether a novel battery of implicit cognition measures is sensitive to the effects of methylphenidate (Ritalin) in healthy volunteers. EXPERIMENTAL APPROACH Eighty healthy volunteers were randomised to receive either a single (10 mg) dose of methylphenidate or matched placebo. Participants completed a battery of tasks measuring implicit cognition (location priming, contextual cueing, implicit task switching). The effect of methylphenidate on standard, explicit measures of cognition was also assessed. KEY RESULTS Methylphenidate enhanced implicit learning on the location priming task and the implicit task-switching task. In line with previous work, we found that these effects were greater in male volunteers. There was no evidence for improved learning in any of the explicit measures. CONCLUSION AND IMPLICATIONS These results demonstrate that implicit measures of cognition are sensitive to pharmacological interventions in healthy volunteers. As such, implicit cognition measures may be a useful way of screening and tracking cognitive effects of novel agents in experimental medicine studies.
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Affiliation(s)
- Corinna Klinge
- 1 Department of Psychiatry, University of Oxford, Oxford, UK.,2 Oxford Health, NHS Foundation Trust, Oxford, UK
| | | | | | - Anna C Nobre
- 4 Oxford Centre for Human Brain Activity, University of Oxford, Oxford, UK.,5 Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Catherine J Harmer
- 1 Department of Psychiatry, University of Oxford, Oxford, UK.,2 Oxford Health, NHS Foundation Trust, Oxford, UK
| | - Susannah E Murphy
- 1 Department of Psychiatry, University of Oxford, Oxford, UK.,2 Oxford Health, NHS Foundation Trust, Oxford, UK
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Schmidt A, Müller F, Dolder PC, Schmid Y, Zanchi D, Egloff L, Liechti ME, Borgwardt S. Acute Effects of Methylphenidate, Modafinil, and MDMA on Negative Emotion Processing. Int J Neuropsychopharmacol 2017; 21:345-354. [PMID: 29206921 PMCID: PMC5887414 DOI: 10.1093/ijnp/pyx112] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 11/22/2017] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Stimulants such as methylphenidate and modafinil are frequently used as cognitive enhancers in healthy people, whereas 3,4-methylenedioxymethamphetamine (ecstasy) is proposed to enhance mood and empathy in healthy subjects. However, comparative data on the effects of methylphenidate and modafinil on negative emotions in healthy subjects have been partially missing. The aim of this study was to compare the acute effects of methylphenidate and modafinil on the neural correlates of fearful face processing using 3,4-methylenedioxymethamphetamine as a positive control. METHODS Using a double-blind, within-subject, placebo-controlled, cross-over design, 60 mg methylphenidate, 600 mg modafinil, and 125 mg 3,4-methylenedioxymethamphetamine were administrated to 22 healthy subjects while performing an event-related fMRI task to assess brain activation in response to fearful faces. Negative mood states were assessed with the State-Trait Anxiety Inventory and subjective ratings. RESULTS Relative to placebo, modafinil, but not methylphenidate or 3,4-methylenedioxymethamphetamine, increased brain activation within a limbic-cortical-striatal-pallidal-thalamic circuit during fearful face processing. Modafinil but not methylphenidate also increased amygdala responses to fearful faces compared with 3,4-methylenedioxymethamphetamine. Furthermore, activation in the middle and inferior frontal gyrus in response to fearful faces correlated positively with subjective feelings of fearfulness and depressiveness after modafinil administration. CONCLUSIONS Despite the cognitive enhancement effects of 600 mg modafinil in healthy people, potential adverse effects on emotion processing should be considered.
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Affiliation(s)
- André Schmidt
- Department of Psychiatry, University of Basel, Basel, Switzerland,Correspondence: André Schmidt, PhD, University of Basel, Department of Psychiatry (UPK), Wilhelm Klein Strasse 27, 4012 Basel, Switzerland ()
| | - Felix Müller
- Department of Psychiatry, University of Basel, Basel, Switzerland
| | - Patrick C Dolder
- Department of Biomedicine, Division of Clinical Pharmacology and Toxicology, University of Basel, Basel, Switzerland,Department of Clinical Research, University Hospital Basel, Basel, Switzerland
| | - Yasmin Schmid
- Department of Biomedicine, Division of Clinical Pharmacology and Toxicology, University of Basel, Basel, Switzerland,Department of Clinical Research, University Hospital Basel, Basel, Switzerland
| | - Davide Zanchi
- Department of Psychiatry, University of Basel, Basel, Switzerland
| | - Laura Egloff
- Department of Psychiatry, University of Basel, Basel, Switzerland
| | - Matthias E Liechti
- Department of Biomedicine, Division of Clinical Pharmacology and Toxicology, University of Basel, Basel, Switzerland,Department of Clinical Research, University Hospital Basel, Basel, Switzerland
| | - Stefan Borgwardt
- Department of Psychiatry, University of Basel, Basel, Switzerland
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Howlett JR, Huang H, Hysek CM, Paulus MP. The effect of single-dose methylphenidate on the rate of error-driven learning in healthy males: a randomized controlled trial. Psychopharmacology (Berl) 2017; 234:3353-3360. [PMID: 28864865 PMCID: PMC5886350 DOI: 10.1007/s00213-017-4723-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 08/14/2017] [Indexed: 12/30/2022]
Abstract
RATIONALE AND OBJECTIVES Norepinephrine mediates the adjustment of error-driven learning to match the rate of change of the environment, while phasic dopamine signals prediction errors. We tested the hypothesis that pharmacologic manipulation may modulate this process. METHODS We administered a single dose of methylphenidate, a norepinephrine/dopamine reuptake inhibitor, or placebo in double-blind randomized fashion to 20 healthy human males, who then performed a probabilistic learning task. Each subject was tested in two sessions, receiving methylphenidate in one session and placebo in the other, in randomized order. Task performance was quantified by the percentage of trials on which subjects chose the most likely option, while learning rate was measured using a computational model-based parameter as well as with a behavioral analogue of this parameter. RESULTS There was a substance-by-session interaction effect on behavioral learning rate and model-based learning rate, such that subjects receiving methylphenidate exhibited higher learning rates than those receiving placebo in session 1, with no difference observed in session 2, suggesting that subjects retained the increased learning rate across sessions. Higher behavioral learning rate was associated with both higher task performance and with the model-based learning rate. Higher learning rates were advantageous given the high rate of change on the task. Subjects receiving methylphenidate and placebo began the task in session 1 with a similar behavioral learning rate, but those receiving methylphenidate rapidly increased learning rate toward the optimal value, suggesting that methylphenidate accelerated the adaptation of learning rate based on the environment. CONCLUSIONS The results suggest that methylphenidate may improve disrupted probabilistic learning in disorders involving noradrenergic or dopaminergic dysfunction.
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Affiliation(s)
- Jonathon R. Howlett
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA,+1 (858) 822-4357,
| | - He Huang
- Laureate Institute for Brain Research, Tulsa, OK, 74136, USA
| | - Cédric M. Hysek
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
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Steen NE, Aas M, Simonsen C, Dieset I, Tesli M, Nerhus M, Gardsjord E, Mørch R, Agartz I, Melle I, Ueland T, Spigset O, Andreassen OA. Serum levels of second-generation antipsychotics are associated with cognitive function in psychotic disorders. World J Biol Psychiatry 2017; 18:471-482. [PMID: 27712130 DOI: 10.1080/15622975.2016.1245441] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVES Antipsychotics are effective in treating psychosis and mood episodes; however, the effect on cognition is less known. We investigated the association between serum levels of second-generation antipsychotics (SGAs) and cognitive performance in psychosis spectrum disorders in a naturalistic setting. METHODS A total of 495 patients with a DSM-IV Schizophrenia and Other Psychotic Disorders (SCZ, n = 373) or Bipolar Disorder (BD, n = 122) diagnosis treated with olanzapine, quetiapine, aripiprazole or risperidone were tested neuropsychologically with concurrent measurement of the serum concentration of the drug. Linear regression was used for association analyses. RESULTS Attention was positively associated with the olanzapine concentration (standardised beta (β) coefficient = 0.19, P = .006), and short-term verbal memory and verbal fluency were negatively associated with the quetiapine (β = -0.24, P = .004) and risperidone (β = -0.37, P = .007) concentrations respectively. CONCLUSIONS The present results suggest that SGA serum concentration is associated with better attention (small effect size), and worse verbal memory (small effect size) and verbal fluency (medium effect size). These findings are in line with the notion that SGAs affect aspects of cognitive function, and suggest careful dosing in patients with severe memory and executive problems.
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Affiliation(s)
- Nils Eiel Steen
- a NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction , Oslo University Hospital, and Institute of Clinical Medicine, University of Oslo , Oslo , Norway.,b Drammen District Psychiatric Center, Clinic of Mental Health and Addiction, Vestre Viken Hospital Trust , Drammen , Norway
| | - Monica Aas
- a NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction , Oslo University Hospital, and Institute of Clinical Medicine, University of Oslo , Oslo , Norway
| | - Carmen Simonsen
- a NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction , Oslo University Hospital, and Institute of Clinical Medicine, University of Oslo , Oslo , Norway
| | - Ingrid Dieset
- a NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction , Oslo University Hospital, and Institute of Clinical Medicine, University of Oslo , Oslo , Norway
| | - Martin Tesli
- a NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction , Oslo University Hospital, and Institute of Clinical Medicine, University of Oslo , Oslo , Norway
| | - Mari Nerhus
- a NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction , Oslo University Hospital, and Institute of Clinical Medicine, University of Oslo , Oslo , Norway
| | - Erlend Gardsjord
- a NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction , Oslo University Hospital, and Institute of Clinical Medicine, University of Oslo , Oslo , Norway
| | - Ragni Mørch
- a NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction , Oslo University Hospital, and Institute of Clinical Medicine, University of Oslo , Oslo , Norway
| | - Ingrid Agartz
- a NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction , Oslo University Hospital, and Institute of Clinical Medicine, University of Oslo , Oslo , Norway.,c Department of Psychiatric Research , Diakonhjemmet Hospital , Oslo , Norway
| | - Ingrid Melle
- a NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction , Oslo University Hospital, and Institute of Clinical Medicine, University of Oslo , Oslo , Norway
| | - Torill Ueland
- a NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction , Oslo University Hospital, and Institute of Clinical Medicine, University of Oslo , Oslo , Norway.,d Department of Psychology , University of Oslo , Oslo , Norway
| | - Olav Spigset
- e Department of Clinical Pharmacology , St. Olav University Hospital , Trondheim , Norway.,f Department of Laboratory Medicine, Children's and Women's Health , Norwegian University of Science and Technology , Trondheim , Norway
| | - Ole A Andreassen
- a NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction , Oslo University Hospital, and Institute of Clinical Medicine, University of Oslo , Oslo , Norway
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Cropsey KL, Schiavon S, Hendricks PS, Froelich M, Lentowicz I, Fargason R. Mixed-amphetamine salts expectancies among college students: Is stimulant induced cognitive enhancement a placebo effect? Drug Alcohol Depend 2017; 178:302-309. [PMID: 28686989 DOI: 10.1016/j.drugalcdep.2017.05.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 04/24/2017] [Accepted: 05/12/2017] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Non-medical use of prescription stimulants for cognitive enhancement in college students is increasing, despite evidence showing little benefit in non-clinical populations. The balanced placebo design (BPD) was used to independently evaluate the pharmacologic versus expectancy effects of mixed amphetamine salts on cognitive performance among a non-clinical sample of college-aged students. METHOD Participants were screened and excluded for ADHD and other psychopathologies. A non-clinical sample (N=32) completed four two-hour laboratory sessions and were administered a neurocognitive battery in each session. Medication Assignment (10mg mixed-amphetamine salt (Adderall™) versus placebo) was crossed with Instructional Set (deception versus truth). A within-subjects design was used, such that all participants experienced each of the four conditions of the BPD during one of the four laboratory sessions. RESULTS Participants performed no better than chance in identifying whether they received stimulant or placebo (Belief about Medication Assignment; 47% agreement; κ=-0.047, p=0.590). Participants showed improvement on only two of 31 subtests during active medication. Expecting and receiving stimulants was associated with improved cognitive performance. However, expecting placebo was associated with worse cognitive performance, regardless of the type of medication given. DISCUSSION This study demonstrated that although non-medical use of stimulants does not enhance cognition, expectancies prominently influence cognitive performance. Participants who believed they received active medication both subjectively rated themselves as performing better and objectively performed better on a minority of subtests, independent of medication state.
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Affiliation(s)
- Karen L Cropsey
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Sparks Center, 1720 2nd Ave. South, Birmingham, AL 35294, USA.
| | - Samantha Schiavon
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Sparks Center, 1720 2nd Ave. South, Birmingham, AL 35294, USA.
| | - Peter S Hendricks
- School of Public Health, Department of Health Behavior, University of Alabama at Birmingham, 227L Ryals Public Health Building, 1665 University Blvd., Birmingham, AL 35294, USA.
| | - Morgan Froelich
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Sparks Center, 1720 2nd Ave. South, Birmingham, AL 35294, USA.
| | - Iga Lentowicz
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Sparks Center, 1720 2nd Ave. South, Birmingham, AL 35294, USA.
| | - Rachel Fargason
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Sparks Center, 1720 2nd Ave. South, Birmingham, AL 35294, USA.
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63
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Methylphenidate Modulates Functional Network Connectivity to Enhance Attention. J Neurosci 2017; 36:9547-57. [PMID: 27629707 DOI: 10.1523/jneurosci.1746-16.2016] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 07/20/2016] [Indexed: 01/07/2023] Open
Abstract
UNLABELLED Recent work has demonstrated that human whole-brain functional connectivity patterns measured with fMRI contain information about cognitive abilities, including sustained attention. To derive behavioral predictions from connectivity patterns, our group developed a connectome-based predictive modeling (CPM) approach (Finn et al., 2015; Rosenberg et al., 2016). Previously using CPM, we defined a high-attention network, comprising connections positively correlated with performance on a sustained attention task, and a low-attention network, comprising connections negatively correlated with performance. Validating the networks as generalizable biomarkers of attention, models based on network strength at rest predicted attention-deficit/hyperactivity disorder (ADHD) symptoms in an independent group of individuals (Rosenberg et al., 2016). To investigate whether these networks play a causal role in attention, here we examined their strength in healthy adults given methylphenidate (Ritalin), a common ADHD treatment, compared with unmedicated controls. As predicted, individuals given methylphenidate showed patterns of connectivity associated with better sustained attention: higher high-attention and lower low-attention network strength than controls. There was significant overlap between the high-attention network and a network with greater strength in the methylphenidate group, and between the low-attention network and a network with greater strength in the control group. Network strength also predicted behavior on a stop-signal task, such that participants with higher go response rates showed higher high-attention and lower low-attention network strength. These results suggest that methylphenidate acts by modulating functional brain networks related to sustained attention, and that changing whole-brain connectivity patterns may help improve attention. SIGNIFICANCE STATEMENT Recent work identified a promising neuromarker of sustained attention based on whole-brain functional connectivity networks. To investigate the causal role of these networks in attention, we examined their response to a dose of methylphenidate, a common and effective treatment for attention-deficit/hyperactivity disorder, in healthy adults. As predicted, individuals on methylphenidate showed connectivity signatures of better sustained attention: higher high-attention and lower low-attention network strength than controls. These results suggest that methylphenidate acts by modulating strength in functional brain networks related to attention, and that changing whole-brain connectivity patterns may improve attention.
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Wu ZM, Bralten J, An L, Cao QJ, Cao XH, Sun L, Liu L, Yang L, Mennes M, Zang YF, Franke B, Hoogman M, Wang YF. Verbal working memory-related functional connectivity alterations in boys with attention-deficit/hyperactivity disorder and the effects of methylphenidate. J Psychopharmacol 2017; 31:1061-1069. [PMID: 28656805 DOI: 10.1177/0269881117715607] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Few studies have investigated verbal working memory-related functional connectivity patterns in participants with attention-deficit/hyperactivity disorder (ADHD). Thus, we aimed to compare working memory-related functional connectivity patterns in healthy children and those with ADHD, and study effects of methylphenidate (MPH). METHOD Twenty-two boys with ADHD were scanned twice, under either MPH (single dose, 10 mg) or placebo, in a randomised, cross-over, counterbalanced placebo-controlled design. Thirty healthy boys were scanned once. We used fMRI during a numerical n-back task to examine functional connectivity patterns in case-control and MPH-placebo comparisons, using independent component analysis. RESULTS There was no significant difference in behavioural performance between children with ADHD, treated with MPH or placebo, and healthy controls. Compared with controls, participants with ADHD under placebo showed increased functional connectivity within fronto-parietal and auditory networks, and decreased functional connectivity within the executive control network. MPH normalized the altered functional connectivity pattern and significantly enhanced functional connectivity within the executive control network, though in non-overlapping areas. CONCLUSION Our study contributes to the identification of the neural substrates of working memory. Single dose of MPH normalized the altered brain functional connectivity network, but had no enhancing effect on (non-impaired) behavioural performance.
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Affiliation(s)
- Zhao-Min Wu
- 1 Peking University Sixth Hospital/Institute of Mental Health, National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China.,2 Key Laboratory of Mental Health, Ministry of Health, Peking University, Beijing, China.,3 Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,4 Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Janita Bralten
- 3 Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,4 Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Li An
- 1 Peking University Sixth Hospital/Institute of Mental Health, National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China.,2 Key Laboratory of Mental Health, Ministry of Health, Peking University, Beijing, China
| | - Qing-Jiu Cao
- 1 Peking University Sixth Hospital/Institute of Mental Health, National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China.,2 Key Laboratory of Mental Health, Ministry of Health, Peking University, Beijing, China
| | - Xiao-Hua Cao
- 1 Peking University Sixth Hospital/Institute of Mental Health, National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China.,2 Key Laboratory of Mental Health, Ministry of Health, Peking University, Beijing, China
| | - Li Sun
- 1 Peking University Sixth Hospital/Institute of Mental Health, National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China.,2 Key Laboratory of Mental Health, Ministry of Health, Peking University, Beijing, China
| | - Lu Liu
- 1 Peking University Sixth Hospital/Institute of Mental Health, National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China.,2 Key Laboratory of Mental Health, Ministry of Health, Peking University, Beijing, China
| | - Li Yang
- 1 Peking University Sixth Hospital/Institute of Mental Health, National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China.,2 Key Laboratory of Mental Health, Ministry of Health, Peking University, Beijing, China
| | - Maarten Mennes
- 4 Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Yu-Feng Zang
- 5 Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China
| | - Barbara Franke
- 3 Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,4 Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.,6 Department of Psychiatry, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Martine Hoogman
- 3 Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,4 Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Yu-Feng Wang
- 1 Peking University Sixth Hospital/Institute of Mental Health, National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, China.,2 Key Laboratory of Mental Health, Ministry of Health, Peking University, Beijing, China
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Cope ZA, Minassian A, Kreitner D, MacQueen DA, Milienne-Petiot M, Geyer MA, Perry W, Young JW. Modafinil improves attentional performance in healthy, non-sleep deprived humans at doses not inducing hyperarousal across species. Neuropharmacology 2017; 125:254-262. [PMID: 28774856 DOI: 10.1016/j.neuropharm.2017.07.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/27/2017] [Accepted: 07/30/2017] [Indexed: 12/18/2022]
Abstract
The wake-promoting drug modafinil is frequently used off-label to improve cognition in psychiatric and academic populations alike. The domain-specific attentional benefits of modafinil have yet to be quantified objectively in healthy human volunteers using tasks validated for comparison across species. Further, given that modafinil is a low-affinity inhibitor for the dopamine and norepinephrine transporters (DAT/NET respectively) it is unclear if any effects are attributable to a non-specific increase in arousal, a feature of many catecholamine reuptake inhibitors (e.g., cocaine, amphetamine). These experiments were designed to test for domain-specific enhancement of attention and cognitive control by modafinil (200 and 400 mg) in healthy volunteers using the 5-choice continuous performance task (5C-CPT) and Wisconsin Card Sort Task (WCST). An additional cross-species assessment of arousal and hyperactivity was performed in this group and in mice (3.2, 10, or 32 mg/kg) using species-specific versions of the behavioral pattern monitor (BPM). Modafinil significantly enhanced attention (d prime) in humans performing the 5C-CPT at doses that did not affect WCST performance or induce hyperactivity in the BPM. In mice, only the highest dose elicited increased activity in the BPM. These results indicate that modafinil produces domain-specific enhancement of attention in humans not driven by hyperarousal, unlike other drugs in this class, and higher equivalent doses were required for hyperarousal in mice. Further, these data support the utility of using the 5C-CPT across species to more precisely determine the mechanism(s) underlying the pro-cognitive effects of modafinil and potentially other pharmacological treatments.
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Affiliation(s)
- Zackary A Cope
- Department of Psychiatry, School of Medicine, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, United States
| | - Arpi Minassian
- Department of Psychiatry, School of Medicine, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, United States; Center for Stress and Mental Health (CESAMH), VA San Diego Healthcare System, San Diego, CA, United States
| | - Dustin Kreitner
- Department of Psychiatry, School of Medicine, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, United States
| | - David A MacQueen
- Department of Psychiatry, School of Medicine, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, United States; Research Service, VA San Diego Healthcare System, San Diego, CA, United States
| | - Morgane Milienne-Petiot
- Department of Psychiatry, School of Medicine, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, United States; Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, David de Wied Building, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Mark A Geyer
- Department of Psychiatry, School of Medicine, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, United States; Research Service, VA San Diego Healthcare System, San Diego, CA, United States
| | - William Perry
- Department of Psychiatry, School of Medicine, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, United States
| | - Jared W Young
- Department of Psychiatry, School of Medicine, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, United States; Research Service, VA San Diego Healthcare System, San Diego, CA, United States.
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66
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Gvirts HZ, Mayseless N, Segev A, Lewis DY, Feffer K, Barnea Y, Bloch Y, Shamay-Tsoory SG. Novelty-seeking trait predicts the effect of methylphenidate on creativity. J Psychopharmacol 2017; 31:599-605. [PMID: 27624151 DOI: 10.1177/0269881116667703] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In recent years the use of psychostimulants for cognitive enhancement in healthy individuals with no psychiatric disorders has been on the rise. However, it is still unclear whether psychostimulants improve certain cognitive functions at the cost of others, and how these psychostimulants interact with individual personality differences. In the current study, we investigated whether the effect of one common stimulant, methylphenidate (MPH), on creativity is associated with novelty seeking. Thirty-six healthy adults, without attention-deficit hyperactivity disorder (ADHD) symptomology, were assigned randomly in a double-blind fashion to receive MPH or placebo. We found that the effect of MPH on creativity was dependent on novelty-seeking (NS) personality characteristics of the participants. MPH increased creativity in individuals with lower NS, while it reduced creativity levels in individuals with high NS. These findings highlight the role of the dopaminergic system in creativity, and indicate that among healthy individuals NS can be seen as a predictor of the effect of MPH on creativity.
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Affiliation(s)
- Hila Z Gvirts
- 1 Department of Psychology, University of Haifa, Haifa, Israel
| | - Naama Mayseless
- 1 Department of Psychology, University of Haifa, Haifa, Israel
| | - Aviv Segev
- 2 Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.,3 The Emotion-Cognition Research Center, Shalvata Mental Health Care Center, Hod-Hasharon, affiliated with the Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - D Yael Lewis
- 2 Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.,3 The Emotion-Cognition Research Center, Shalvata Mental Health Care Center, Hod-Hasharon, affiliated with the Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Kfir Feffer
- 2 Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.,3 The Emotion-Cognition Research Center, Shalvata Mental Health Care Center, Hod-Hasharon, affiliated with the Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Yael Barnea
- 2 Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Yuval Bloch
- 2 Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.,3 The Emotion-Cognition Research Center, Shalvata Mental Health Care Center, Hod-Hasharon, affiliated with the Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
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67
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Bosker WM, Neuner I, Shah NJ. The role of impulsivity in psychostimulant- and stress-induced dopamine release: Review of human imaging studies. Neurosci Biobehav Rev 2017; 78:82-90. [PMID: 28438467 DOI: 10.1016/j.neubiorev.2017.04.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 02/13/2017] [Accepted: 04/11/2017] [Indexed: 12/21/2022]
Abstract
Drug addiction is a debilitating disorder and its pivotal problem is the high relapse rate. To solve this problem, the aim is to prevent people from becoming addicted in the first place. One of the key questions that is still unanswered is why some people become addicted to drugs and others, who take drugs regularly, do not. In recent years extensive research has been done to untangle the many factors involved in this disorder. Here, we review some of the factors that are related to dopamine, i.e., impulsivity and stress (hormones), and aim to integrate this into a neurobiological model. Based on this, we draw two conclusions: (1) in order to understand the transition from recreational drug use to addiction, we need to focus more on these recreational users; and (2) research should be aimed at finding therapies that can restore inhibitory control/frontal functioning and improve stress resiliency in addicts.
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Affiliation(s)
- Wendy M Bosker
- Institute of Neuroscience and Medicine (INM-4/INM-11), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
| | - Irene Neuner
- Institute of Neuroscience and Medicine (INM-4/INM-11), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany; JARA - Translational Brain Medicine, RWTH Aachen University, 52074 Aachen, Germany; Department of Psychiatry, Psychotherapy and Psychosomatic Disorders, University Clinic Aachen, 52074 Aachen, Germany.
| | - N Jon Shah
- Institute of Neuroscience and Medicine (INM-4/INM-11), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany; JARA - Translational Brain Medicine, RWTH Aachen University, 52074 Aachen, Germany; Department of Psychiatry, Psychotherapy and Psychosomatic Disorders, University Clinic Aachen, 52074 Aachen, Germany; Department of Neurology, University Clinic Aachen, 52074 Aachen, Germany; Department of Electrical and Computer Systems Engineering, and Monash Biomedical Imaging, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
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68
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Olde Dubbelink LME, Geurts HM. Planning Skills in Autism Spectrum Disorder Across the Lifespan: A Meta-analysis and Meta-regression. J Autism Dev Disord 2017; 47:1148-1165. [PMID: 28160225 PMCID: PMC5357294 DOI: 10.1007/s10803-016-3013-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Individuals with an autism spectrum disorder (ASD) are thought to encounter planning difficulties, but experimental research regarding the mastery of planning in ASD is inconsistent. By means of a meta-analysis of 50 planning studies with a combined sample size of 1755 individuals with and 1642 without ASD, we aim to determine whether planning difficulties do exist and which factors contribute to this. Planning problems were evident in individuals with ASD (Hedges'g = 0.52), even when taking publication bias into account (Hedges'g = 0.37). Neither age, nor task-type, nor IQ reduced the observed heterogeneity, suggesting that these were not crucial moderators within the current meta-analysis. However, while we showed that ASD individuals encounter planning difficulties, the bias towards publishing positive findings restricts strong conclusions regarding the role of potential moderators.
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Affiliation(s)
- Linda M E Olde Dubbelink
- Dr. Leo Kannerhuis, Houtsniplaan 1, 6865 XZ, Doowerth, The Netherlands.
- Dutch Autism & ADHD Research Center (d'Arc), Department of Psychology, Division Brain & Cognition, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, The Netherlands.
| | - Hilde M Geurts
- Dr. Leo Kannerhuis, Houtsniplaan 1, 6865 XZ, Doowerth, The Netherlands
- Dutch Autism & ADHD Research Center (d'Arc), Department of Psychology, Division Brain & Cognition, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS, Amsterdam, The Netherlands
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69
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Van Zyl PM, Joubert G, Fechter L, Griesel J, Nel M, Honiball A, Serfontein L, Diedericks M. Methylphenidate use among students living in junior on-campus residences of the University of the Free State. S Afr Fam Pract (2004) 2017. [DOI: 10.1080/20786190.2017.1292695] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Affiliation(s)
- PM Van Zyl
- Department of Pharmacology, University of the Free State, Bloemfontein, South Africa
| | - G Joubert
- Department of Biostatistics, University of the Free State, Bloemfontein, South Africa
| | - L Fechter
- School of Medicine, University of the Free State, Bloemfontein, South Africa
| | - J Griesel
- School of Medicine, University of the Free State, Bloemfontein, South Africa
| | - M Nel
- School of Medicine, University of the Free State, Bloemfontein, South Africa
| | - A Honiball
- School of Medicine, University of the Free State, Bloemfontein, South Africa
| | - L Serfontein
- School of Medicine, University of the Free State, Bloemfontein, South Africa
| | - M Diedericks
- School of Medicine, University of the Free State, Bloemfontein, South Africa
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70
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Mous SE, White T, Muetzel RL, El Marroun H, Rijlaarsdam J, Polderman TJ, Jaddoe VW, Verhulst FC, Posthuma D, Tiemeier H. Cortical morphology as a shared neurobiological substrate of attention-deficit/hyperactivity symptoms and executive functioning: a population-based pediatric neuroimaging study. J Psychiatry Neurosci 2017; 42:103-112. [PMID: 27673503 PMCID: PMC5373699 DOI: 10.1503/jpn.150371] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Attention-deficit/hyperactivity symptoms have repeatedly been associated with poor cognitive functioning. Genetic studies have demonstrated a shared etiology of attention-deficit/hyperactivity disorder (ADHD) and cognitive ability, suggesting a common underlying neurobiology of ADHD and cognition. Further, neuroimaging studies suggest that altered cortical development is related to ADHD. In a large population-based sample we investigated whether cortical morphology, as a potential neurobiological substrate, underlies the association between attention-deficit/hyperactivity symptoms and cognitive problems. METHODS The sample consisted of school-aged children with data on attention-deficit/hyperactivity symptoms, cognitive functioning and structural imaging. First, we investigated the association between attention-deficit/ hyperactivity symptoms and different domains of cognition. Next, we identified cortical correlates of attention-deficit/hyperactivity symptoms and related cognitive domains. Finally, we studied the role of cortical thickness and gyrification in the behaviour-cognition associations. RESULTS We included 776 children in our analyses. We found that attention-deficit/hyperactivity symptoms were associated specifically with problems in attention and executive functioning (EF; b = -0.041, 95% confidence interval [CI] -0.07 to -0.01, p = 0.004). Cortical thickness and gyrification were associated with both attention-deficit/hyperactivity symptoms and EF in brain regions that have been previously implicated in ADHD. This partly explained the association between attention-deficit/hyperactivity symptoms and EF (bindirect = -0.008, bias-corrected 95% CI -0.018 to -0.001). LIMITATIONS The nature of our study did not allow us to draw inferences regarding temporal associations; longitudinal studies are needed for clarification. CONCLUSION In a large, population-based sample of children, we identified a shared cortical morphology underlying attention-deficit/hyperactivity symptoms and EF.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Henning Tiemeier
- Correspondence to: H. Tiemeier, Erasmus MC, Department of Epidemiology, room Na-2818, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands;
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Franke AG, Gränsmark P, Agricola A, Schühle K, Rommel T, Sebastian A, Balló HE, Gorbulev S, Gerdes C, Frank B, Ruckes C, Tüscher O, Lieb K. Methylphenidate, modafinil, and caffeine for cognitive enhancement in chess: A double-blind, randomised controlled trial. Eur Neuropsychopharmacol 2017; 27:248-260. [PMID: 28119083 DOI: 10.1016/j.euroneuro.2017.01.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 12/14/2016] [Accepted: 01/05/2017] [Indexed: 10/20/2022]
Abstract
Stimulants and caffeine have been proposed for cognitive enhancement by healthy subjects. This study investigated whether performance in chess - a competitive mind game requiring highly complex cognitive skills - can be enhanced by methylphenidate, modafinil or caffeine. In a phase IV, randomized, double-blind, placebo-controlled trial, 39 male chess players received 2×200mg modafinil, 2×20mg methylphenidate, and 2×200mg caffeine or placebo in a 4×4 crossover design. They played twenty 15-minute games during two sessions against a chess program (Fritz 12; adapted to players' strength) and completed several neuropsychological tests. Marked substance effects were observed since all three substances significantly increased average reflection time per game compared to placebo resulting in a significantly increased number of games lost on time with all three treatments. Treatment effects on chess performance were not seen if all games (n=3059) were analysed. Only when controlling for game duration as well as when excluding those games lost on time, both modafinil and methylphenidate enhanced chess performance as demonstrated by significantly higher scores in the remaining 2876 games compared to placebo. In conjunction with results from neuropsychological testing we conclude that modifying effects of stimulants on complex cognitive tasks may in particular result from more reflective decision making processes. When not under time pressure, such effects may result in enhanced performance. Yet, under time constraints more reflective decision making may not improve or even have detrimental effects on complex task performance.
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Affiliation(s)
- Andreas G Franke
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Untere Zahlbacher Str. 8, D-55131 Mainz, Germany; University of Neubrandenburg, University of Applied Sciences, Department of Social Work and Education, Brodaer Str. 2, 17033 Neubrandenburg, Germany.
| | - Patrik Gränsmark
- SOFI, Stockholm University, Swedish Institute for Social Research, Stockholm University, SE - 10691 Stockholm, Sweden.
| | - Alexandra Agricola
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Untere Zahlbacher Str. 8, D-55131 Mainz, Germany.
| | - Kai Schühle
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Untere Zahlbacher Str. 8, D-55131 Mainz, Germany.
| | - Thilo Rommel
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Untere Zahlbacher Str. 8, D-55131 Mainz, Germany; Department of Psychology, Section for Clinical Psychology and Psychotherapy, University of Mainz, Wallstr. 3, 55122 Mainz, Germany.
| | - Alexandra Sebastian
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Untere Zahlbacher Str. 8, D-55131 Mainz, Germany.
| | - Harald E Balló
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Untere Zahlbacher Str. 8, D-55131 Mainz, Germany; Internistisch-onkologische Gemeinschaftspraxis, Marktplatz 11, 63065 Offenbach am Main, Germany.
| | - Stanislav Gorbulev
- Interdisciplinary Center for Clinical Trials (IZKS), University Medical Center Mainz, Langenbeckstr. 1, 55131 Mainz, Germany.
| | - Christer Gerdes
- SOFI, Stockholm University, Swedish Institute for Social Research, Stockholm University, SE - 10691 Stockholm, Sweden.
| | - Björn Frank
- University of Kassel, Department of Economics, Nora-Platiel-Str. 4, 34127 Kassel, Germany.
| | - Christian Ruckes
- Interdisciplinary Center for Clinical Trials (IZKS), University Medical Center Mainz, Langenbeckstr. 1, 55131 Mainz, Germany.
| | - Oliver Tüscher
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Untere Zahlbacher Str. 8, D-55131 Mainz, Germany.
| | - Klaus Lieb
- Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Untere Zahlbacher Str. 8, D-55131 Mainz, Germany.
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Benn A, Robinson ESJ. Differential roles for cortical versus sub-cortical noradrenaline and modulation of impulsivity in the rat. Psychopharmacology (Berl) 2017; 234:255-266. [PMID: 27744551 PMCID: PMC5203835 DOI: 10.1007/s00213-016-4458-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 10/03/2016] [Indexed: 12/31/2022]
Abstract
RATIONALE Atomoxetine is a noradrenaline re-uptake inhibitor licensed for the treatment of adult and childhood attention deficit hyperactivity disorder. Although atomoxetine has established efficacy, the mechanisms which mediate its effects are not well understood. OBJECTIVES In this study, we investigated the role of cortical versus sub-cortical noradrenaline by using focal dopamine beta hydroxylase-saporin-induced lesions, to the prefrontal cortex (n = 16) or nucleus accumbens shell (n = 18). METHODS Healthy animals were tested by using the forced-choice serial reaction time task to assess the impact of the lesion on baseline performance and the response to atomoxetine and the psychostimulant amphetamine. RESULTS We observed attenuation in the efficacy of atomoxetine in animals with lesions to the nucleus accumbens shell, but not the prefrontal cortex. Amphetamine-induced increases in premature responses were potentiated in animals with lesions to the prefrontal cortex, but not the nucleus accumbens shell. CONCLUSIONS These data suggest that noradrenaline in the nucleus accumbens shell plays an important role in the effects of atomoxetine. Under these conditions, prefrontal cortex noradrenaline did not appear to contribute to atomoxetine's effects suggesting a lack of cortical-mediated "top-down" modulation. Noradrenaline in the prefrontal cortex appears to contribute to the modulation of impulsive responding in amphetamine-treated animals, with a loss of noradrenaline associated with potentiation of its effects. These data demonstrate a potential dissociation between cortical and sub-cortical noradrenergic mechanisms and impulse control in terms of the actions of atomoxetine and amphetamine.
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Affiliation(s)
- Abigail Benn
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Emma S J Robinson
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK.
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73
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Wagner IC, van Buuren M, Bovy L, Morris RG, Fernández G. Methylphenidate during early consolidation affects long-term associative memory retrieval depending on baseline catecholamines. Psychopharmacology (Berl) 2017; 234:657-669. [PMID: 28013352 PMCID: PMC5263224 DOI: 10.1007/s00213-016-4502-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 12/05/2016] [Indexed: 12/03/2022]
Abstract
RATIONALE Synaptic memory consolidation is thought to rely on catecholaminergic signaling. Eventually, it is followed by systems consolidation, which embeds memories in a neocortical network. Although this sequence was demonstrated in rodents, it is unclear how catecholamines affect memory consolidation in humans. OBJECTIVES Here, we tested the effects of catecholaminergic modulation on synaptic and subsequent systems consolidation. We expected enhanced memory performance and increased neocortical engagement during delayed retrieval. Additionally, we tested if this effect was modulated by individual differences in a cognitive proxy measure of baseline catecholamine synthesis capacity. METHODS Fifty-three healthy males underwent a between-subjects, double-blind, placebo-controlled procedure across 2 days. On day 1, subjects studied and retrieved object-location associations and received 20 mg of methylphenidate or placebo. Drug intake was timed so that methylphenidate was expected to affect early consolidation but not encoding or retrieval. Memory was tested again while subjects were scanned three days later. RESULTS Methylphenidate did not facilitate memory performance, and there was no significant group difference in activation during delayed retrieval. However, memory representations differed between groups depending on baseline catecholamines. The placebo group showed increased activation in occipito-temporal regions but decreased connectivity with the hippocampus, associated with lower baseline catecholamine synthesis capacity. The methylphenidate group showed stronger activation in the postcentral gyrus, associated with higher baseline catecholamine synthesis capacity. CONCLUSIONS Altogether, methylphenidate during early consolidation did not foster long-term memory performance, but it affected retrieval-related neural processes depending on individual levels of baseline catecholamines.
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Affiliation(s)
- Isabella C Wagner
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Center, Kapittelweg 29, Nijmegen, 6525 EN, The Netherlands.
| | - Mariët van Buuren
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Center, Kapittelweg 29, Nijmegen, 6525 EN, The Netherlands
| | - Leonore Bovy
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Center, Kapittelweg 29, Nijmegen, 6525 EN, The Netherlands
| | - Richard G Morris
- Centre for Cognitive and Neural Systems, University of Edinburgh, Edinburgh, EH8 9JZ, UK
| | - Guillén Fernández
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Center, Kapittelweg 29, Nijmegen, 6525 EN, The Netherlands
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74
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Neural effects of methylphenidate and nicotine during smooth pursuit eye movements. Neuroimage 2016; 141:52-59. [DOI: 10.1016/j.neuroimage.2016.07.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 06/13/2016] [Accepted: 07/06/2016] [Indexed: 12/11/2022] Open
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Sharma K, Davis T, Coulthard E. Enhancing attention in neurodegenerative diseases: current therapies and future directions. Transl Neurosci 2016; 7:98-109. [PMID: 28123829 PMCID: PMC5234525 DOI: 10.1515/tnsci-2016-0016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/17/2016] [Indexed: 01/04/2023] Open
Abstract
We all experience at least occasional lapses in attention but in some neurological conditions, loss of attention is pervasive and debilitating. Treating deficits in attention first requires an understanding of the neurobiology of attention, which we now understand to be a set of different cognitive processes. Cholinesterase inhibitors are already established as effective attentional enhancers used in the treatment of certain dementias. Other stimulant agents such as modafanil, amphetamine and methylphenidate have demonstrated limited success in healthy individuals where attention is already optimal and clinical trials in patients with neurological disease are sparse. Dietary and lifestyle changes are gaining increasing prominence, as are experimental treatments such as deep brain stimulation and transcranial magnetic stimulation. As the therapeutic arsenal widens, clinicians will be able to match specific treatments to selective deficits in attention, giving patients a tailored management plan. Here we review common diseases that impair attention and emphasise how an understanding of attentional processing within the brain might lead to improved therapeutic strategies.
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Affiliation(s)
- Kanchan Sharma
- ReMemBr group (Research in Memory, the Brain and dementia) School of Clinical Sciences, University of Bristol Level 1, Learning and Research Southmead Hospital, Bristol BS10 5NB, United Kingdom
| | - Thomas Davis
- ReMemBr group (Research in Memory, the Brain and dementia) School of Clinical Sciences, University of Bristol Level 1, Learning and Research Southmead Hospital, Bristol BS10 5NB, United Kingdom
| | - Elizabeth Coulthard
- ReMemBr group (Research in Memory, the Brain and dementia) School of Clinical Sciences, University of Bristol Level 1, Learning and Research Southmead Hospital, Bristol BS10 5NB, United Kingdom
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Methylphenidate does not enhance visual working memory but benefits motivation in macaque monkeys. Neuropharmacology 2016; 109:223-235. [DOI: 10.1016/j.neuropharm.2016.06.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 06/14/2016] [Accepted: 06/17/2016] [Indexed: 02/04/2023]
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Ernst M, Lago T, Davis A, Grillon C. The effects of methylphenidate and propranolol on the interplay between induced-anxiety and working memory. Psychopharmacology (Berl) 2016; 233:3565-74. [PMID: 27492789 PMCID: PMC5131568 DOI: 10.1007/s00213-016-4390-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/18/2016] [Indexed: 02/04/2023]
Abstract
RATIONALE Research documents a reciprocal impact of anxiety on working memory (WM), although its strength and direction depend on factors like task difficulty. A better understanding of these factors may generate insights into cognitive mechanisms of action involved in anxiety, culminating into treatment implications. By blocking the physiological effects of anxiety, propranolol might also block anxiety interference on WM. Conversely, by improving task-directed attention, methylphenidate might reduce anxiety, or, alternatively, by improving cognitive efficiency and free up processing resources to compute anxiety. OBJECTIVES To investigate the interplay between induced anxiety and WM, we pharmacologically manipulated either anxiety or cognition, using single doses of 40 mg propranolol (PRO), 20 mg methylphenidate (MPH), or placebo (PLA). In this double-blind parallel-group design study, 60 healthy volunteers (20/drug group) performed a verbal WM task under three loads, 1-, 2- and 3-back, and in two conditions, threat of shock and safety. Startle electromyography (EMG) was used to measure anxiety. RESULTS Findings were twofold: (1) MPH blocked anxiety interference only on the 3-back WM performance, while PRO or PLA had no effects on anxiety-WM interference, and (2) drugs had no effects on anxiety, but, after controlling for baseline anxiety, MPH enhanced anxiety-potentiated startle during the 3-back task. CONCLUSIONS These findings support that MPH-related improvement of cognitive efficiency permits anxiety to be processed and expressed. In conclusion, MPH may be a useful tool to investigate the mechanisms of interaction between anxiety and WM, particularly those under catecholaminergic control.
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Affiliation(s)
- Monique Ernst
- Neurobiology of Fear and Anxiety, National Institute of Mental Health, 15K North Drive, Bldg 15K, MSC 2670, Bethesda, MD, 20892-2670, USA.
| | - Tiffany Lago
- Neurobiology of Fear and Anxiety, National Institute of Mental Health, 15K North Drive, Bldg 15K, MSC 2670, Bethesda, MD, 20892-2670, USA
| | - Andrew Davis
- Neurobiology of Fear and Anxiety, National Institute of Mental Health, 15K North Drive, Bldg 15K, MSC 2670, Bethesda, MD, 20892-2670, USA
| | - Christian Grillon
- Neurobiology of Fear and Anxiety, National Institute of Mental Health, 15K North Drive, Bldg 15K, MSC 2670, Bethesda, MD, 20892-2670, USA
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Abstract
As the first drug to see widespread use for the treatment of attention deficit hyperactivity disorder (ADHD), methylphenidate was the forerunner and catalyst to the modern era of rapidly increasing diagnosis, treatment, and medication development for this condition. During its often controversial history, it has variously elucidated the importance of dopamine signaling in memory and attention, provoked concerns about pharmaceutical cognitive enhancement, driven innovation in controlled-release technologies and enantiospecific therapeutics, and stimulated debate about the impact of pharmaceutical sales techniques on the practice of medicine. In this Review, we will illustrate the history and importance of methylphenidate to ADHD treatment and neuroscience in general, as well as provide key information about its synthesis, structure-activity relationship, pharmacological activity, metabolism, manufacturing, FDA-approved indications, and adverse effects.
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Affiliation(s)
- Cody J. Wenthur
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
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79
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Marraccini ME, Weyandt LL, Rossi JS, Gudmundsdottir BG. Neurocognitive enhancement or impairment? A systematic meta-analysis of prescription stimulant effects on processing speed, decision-making, planning, and cognitive perseveration. Exp Clin Psychopharmacol 2016; 24:269-84. [PMID: 27454675 PMCID: PMC4968888 DOI: 10.1037/pha0000079] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Increasing numbers of adults, particularly college students, are misusing prescription stimulants primarily for cognitive/academic enhancement, so it is critical to explore whether empirical findings support neurocognitive benefits of prescription stimulants. Previous meta-analytic studies have supported small benefits from prescription stimulants for the cognitive domains of inhibitory control and memory; however, no meta-analytic studies have examined the effects on processing speed or the potential impairment on other domains of cognition, including planning, decision-making, and cognitive perseveration. Therefore, the present study conducted a meta-analysis of the available literature examining the effects of prescription stimulants on specific measures of processing speed, planning, decision-making, and cognitive perseveration among healthy adult populations. The meta-analysis results indicated a positive influence of prescription stimulant medication on processing speed accuracy, with an overall mean effect size of g = 0.282 (95% CI [0.077, 0.488]; n = 345). Neither improvements nor impairments were revealed for planning time, planning accuracy, advantageous decision-making, or cognitive perseveration; however, findings are limited by the small number of studies examining these outcomes. Findings support that prescription stimulant medication may indeed act as a neurocognitive enhancer for accuracy measures of processing speed without impeding other areas of cognition. Considering that adults are already engaging in illegal use of prescription stimulants for academic enhancement, as well as the potential for stimulant misuse to have serious side effects, the establishment of public policies informed by interdisciplinary research surrounding this issue, whether restrictive or liberal, is of critical importance. (PsycINFO Database Record
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Affiliation(s)
- Marisa E. Marraccini
- Department of Psychiatry and Human Behavior, Alpert Medical School, Brown University, USA,Department of Psychology, The University of Rhode Island, Kingston, RI, USA
| | - Lisa L. Weyandt
- Department of Psychology, The University of Rhode Island, Kingston, RI, USA
| | - Joseph S. Rossi
- Department of Psychology, The University of Rhode Island, Kingston, RI, USA
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80
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Batistela S, Bueno OFA, Vaz LJ, Galduróz JCF. Methylphenidate as a cognitive enhancer in healthy young people. Dement Neuropsychol 2016; 10:134-142. [PMID: 29213444 PMCID: PMC5642404 DOI: 10.1590/s1980-5764-2016dn1002009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The so-called cognitive enhancers have been widely and increasingly used by healthy individuals who seek improvements in cognitive performance despite having no pathologies. One drug used for this purpose is methylphenidate, a first-line drug for the treatment of attention deficit hyperactivity disorder (ADHD). Objective The aim of the present study was to test the effect of acute administration of varying doses of methylphenidate (10 mg, 20 mg, 40 mg and placebo) on a wide range of cognitive functions in healthy young people. Methods A total of 36 young university students and graduates participated in the study. The participants underwent tests of attention and of episodic, and working memory. Results No differences in performance were observed on any of the tests. There was a dose-dependent (40 mg > placebo) effect on self-reported wellbeing. Conclusions According to the recent literature, psychostimulant medications, such as methylphenidate, improve performance when cognitive processes are below an optimal level, which was not the case for the subjects of the present study. We suggest the impression that methylphenidate enhances cognitive performance in healthy young people, justifying its use, may be due to improvements in subjective wellbeing promoted by the drug.
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Affiliation(s)
- Silmara Batistela
- MS, Departamento de Psicobiologia - Universidade Federal de São Paulo, São Paulo SP, Brazil
| | | | - Leonardo José Vaz
- PhD,Departamento de Psicobiologia - Universidade Federal de São Paulo, São Paulo SP, Brazil
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81
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Fuermaier ABM, Tucha L, Koerts J, Weisbrod M, Lange KW, Aschenbrenner S, Tucha O. Effects of methylphenidate on memory functions of adults with ADHD. APPLIED NEUROPSYCHOLOGY-ADULT 2016; 24:199-211. [DOI: 10.1080/23279095.2015.1124108] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Anselm B. M. Fuermaier
- Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen, The Netherlands
| | - Lara Tucha
- Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen, The Netherlands
| | - Janneke Koerts
- Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen, The Netherlands
| | - Matthias Weisbrod
- Department of Psychiatry and Psychotherapy, SRH Clinic Karlsbad-Langensteinbach, Karlsbad-Langensteinbach, Germany
- Section for Experimental Psychopathology, Centre for Psychosocial Medicine, University of Heidelberg, Heidelberg, Germany
| | - Klaus W. Lange
- Department of Experimental Psychology, University of Regensburg, Regensburg, Germany
| | - Steffen Aschenbrenner
- Department of Clinical Psychology and Neuropsychology, SRH Clinic Karlsbad-Langensteinbach, Karlsbad-Langensteinbach, Germany
| | - Oliver Tucha
- Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen, The Netherlands
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82
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Brühl AB, Sahakian BJ. Drugs, games, and devices for enhancing cognition: implications for work and society. Ann N Y Acad Sci 2016; 1369:195-217. [PMID: 27043232 DOI: 10.1111/nyas.13040] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 02/15/2016] [Accepted: 02/18/2016] [Indexed: 12/11/2022]
Abstract
As work environments change, the demands on working people change. Cognitive abilities in particular are becoming progressively more important for work performance and successful competition in a global environment. However, work-related stress, performance over long hours, lack of sleep, shift work, and jet lag affect cognitive functions. Therefore, an increasing number of healthy people are reported to use cognitive-enhancing drugs, as well as other interventions, such as noninvasive brain stimulation, to maintain or improve work performance. This review summarizes research on pharmacological and technical methods as well as cognitive training, including game apps for the brain, in healthy people. In neuropsychiatric disorders, impairments in cognitive functions can drastically reduce the chances of returning to work; therefore, this review also summarizes findings from pharmacological and cognitive-training studies in neuropsychiatric disorders.
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Affiliation(s)
- Annette B Brühl
- Department of Psychiatry, and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom.,Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry Zurich, Zürich, Switzerland
| | - Barbara J Sahakian
- Department of Psychiatry, and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom
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83
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van Amelsvoort T, Hernaus D. Effect of Pharmacological Interventions on the Fronto-Cingulo-Parietal Cognitive Control Network in Psychiatric Disorders: A Transdiagnostic Systematic Review of fMRI Studies. Front Psychiatry 2016; 7:82. [PMID: 27242552 PMCID: PMC4870274 DOI: 10.3389/fpsyt.2016.00082] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 04/26/2016] [Indexed: 01/10/2023] Open
Abstract
Executive function deficits, such as working memory, decision-making, and attention problems, are a common feature of several psychiatric disorders for which no satisfactory treatment exists. Here, we transdiagnostically investigate the effects of pharmacological interventions (other than methylphenidate) on the fronto-cingulo-parietal cognitive control network, in order to identify functional brain markers for future procognitive pharmacological interventions. Twenty-nine manuscripts investigated the effect of pharmacological treatment on executive function-related brain correlates in psychotic disorders (n = 11), depression (n = 4), bipolar disorder (n = 4), ADHD (n = 4), OCD (n = 2), smoking dependence (n = 2), alcohol dependence (n = 1), and pathological gambling (n = 1). In terms of impact on the fronto-cingulo-parietal network, the preliminary evidence for catechol-O-methyl-transferase inhibitors, nicotinic receptor agonists, and atomoxetine was relatively consistent, the data for atypical antipsychotics and anticonvulsants moderate, and interpretation of the data for antidepressants was hampered by the employed study designs. Increased activity in task-relevant areas and decreased activity in task-irrelevant areas were the most common transdiagnostic effects of pharmacological treatment. These markers showed good positive and moderate negative predictive value. It is concluded that fronto-cingulo-parietal activity changes can serve as a marker for future procognitive interventions. Future recommendations include the use of randomized double-blind designs and selective cholinergic and glutamatergic compounds.
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Affiliation(s)
- Thérèse van Amelsvoort
- Department of Psychiatry and Neuropsychology, South Limburg Mental Health Research and Teaching Network, EURON, School for Mental Health and NeuroScience MHeNS Maastricht University , Maastricht , Netherlands
| | - Dennis Hernaus
- Department of Psychiatry and Neuropsychology, South Limburg Mental Health Research and Teaching Network, EURON, School for Mental Health and NeuroScience MHeNS Maastricht University , Maastricht , Netherlands
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84
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Caviola L, Faber NS. Pills or Push-Ups? Effectiveness and Public Perception of Pharmacological and Non-Pharmacological Cognitive Enhancement. Front Psychol 2015; 6:1852. [PMID: 26696922 PMCID: PMC4667098 DOI: 10.3389/fpsyg.2015.01852] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 11/16/2015] [Indexed: 12/13/2022] Open
Abstract
We review work on the effectiveness of different forms of cognitive enhancement, both pharmacological and non-pharmacological. We consider caffeine, methylphenidate, and modafinil for pharmacological cognitive enhancement (PCE) and computer training, physical exercise, and sleep for non-pharmacological cognitive enhancement (NPCE). We find that all of the techniques described can produce significant beneficial effects on cognitive performance. However, effect sizes are moderate, and consistently dependent on individual and situational factors as well as the cognitive domain in question. Although meta-analyses allowing a quantitative comparison of effectiveness across techniques are lacking to date, we can conclude that PCE is not more effective than NPCE. We discuss the physiological reasons for this limited effectiveness. We then propose that even though their actual effectiveness seems similar, in the general public PCE is perceived as fundamentally different from NPCE, in terms of effectiveness, but also in terms of acceptability. We illustrate the potential consequences such a misperception of PCE can have.
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Affiliation(s)
- Lucius Caviola
- Department of Experimental Psychology, University of Oxford Oxford, UK
| | - Nadira S Faber
- Department of Experimental Psychology, University of Oxford Oxford, UK ; Oxford Martin School, University of Oxford Oxford, UK
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85
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Methylphenidate alters selective attention by amplifying salience. Psychopharmacology (Berl) 2015; 232:4317-23. [PMID: 26349753 DOI: 10.1007/s00213-015-4059-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 08/24/2015] [Indexed: 10/23/2022]
Abstract
RATIONALE Methylphenidate, the most common treatment of attention deficit hyperactivity disorder (ADHD), is increasingly used by healthy individuals as a "smart drug" to enhance cognitive abilities like attention. A key feature of (selective) attention is the ability to ignore irrelevant but salient information in the environment (distractors). Although crucial for cognitive performance, until now, it is not known how the use of methylphenidate affects resistance to attentional capture by distractors. OBJECTIVES The present study aims to clarify how methylphenidate affects distractor suppression in healthy individuals. METHODS The effect of methylphenidate (20 mg) on distractor suppression was assessed in healthy subjects (N = 20), in a within-subject double-blind placebo-controlled crossover design. We used a visuospatial attention task with target faces flanked by strong (faces) or weak distractors (scrambled faces). RESULTS Methylphenidate increased accuracy on trials that required gender identification of target face stimuli (methylphenidate 88.9 ± 1.4 [mean ± SEM], placebo 86.0 ± 1.2 %; p = .003), suggesting increased processing of the faces. At the same time, however, methylphenidate increased reaction time when the target face was flanked by a face distractor relative to a scrambled face distractor (methylphenidate 34.9 ± 3.73, placebo 26.7 ± 2.84 ms; p = .027), suggesting enhanced attentional capture by distractors with task-relevant features. CONCLUSIONS We conclude that methylphenidate amplifies salience of task-relevant information at the level of the stimulus category. This leads to enhanced processing of the target (faces) but also increased attentional capture by distractors drawn from the same category as the target.
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86
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Ettinger U, Merten N, Kambeitz J. Meta-analysis of the association of the SLC6A3 3'-UTR VNTR with cognition. Neurosci Biobehav Rev 2015; 60:72-81. [PMID: 26593110 DOI: 10.1016/j.neubiorev.2015.09.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 09/04/2015] [Accepted: 09/24/2015] [Indexed: 12/19/2022]
Abstract
The gene coding for the dopamine transporter (DAT), SLC6A3, contains a 40-base pair variable number of tandem repeats (VNTR) polymorphism (rs28363170) in its 3' untranslated region. This VNTR has been associated with attention deficit hyperactivity disorder (ADHD) and has been investigated in relation to cognition and brain function. Here, we report the results of a comprehensive meta-analysis with meta-regression examining the association of the VNTR with different domains of cognition in healthy adults. We extracted data from 28 independent studies and carried out meta-analyses for associations with working memory (k=10 samples, N=1193 subjects), inhibition (k=8 samples, N=829 subjects), executive functions including inhibition (k=10 samples, N=984 subjects), attention (k=6 samples, N=742 subjects) and declarative long-term memory (k=5 samples, N=251 subjects). None of the investigated dimensions showed significant associations with the VNTR (all p>0.26). Meta-regression including year of publication, gender, age, ethnicity and percentage of 10R-homozygotes similarly did not attain significance. We conclude that there is no evidence that rs28363170 may be a significant predictor of cognitive function in healthy adults.
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Affiliation(s)
- Ulrich Ettinger
- Department of Psychology, University of Bonn, Bonn, Germany.
| | | | - Joseph Kambeitz
- Department of Psychiatry, University of Munich, Munich, Germany
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Aprigio D, Adolfo W, Bittencourt J, Gongora M, Teixeira S, Basile LF, Budde H, Cagy M, Ribeiro P, Velasques B. Alpha power oscillation in the frontal cortex under Bromazepam and Modafinil effects. ARQUIVOS DE NEURO-PSIQUIATRIA 2015; 73:918-23. [PMID: 26517214 DOI: 10.1590/0004-282x20150140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 08/10/2015] [Indexed: 11/21/2022]
Abstract
OBJECTIVE Our aim was to investigate and compare the neuromodulatory effects of bromazepam (6 mg) and modafinil (200 mg) during a sensorimotor task analyzing the changes produced in the absolute alpha power. METHOD The sample was composed of 15 healthy individuals exposed to three experimental conditions: placebo, modafinil and bromazepam. EEG data were recorded before, during and after the execution of the task. A three-way ANOVA was applied, in order to compare the absolute alpha power among the factors: Group (control, bromazepam and modafinil) Condition (Pre and Post-drug ingestion) and Moment (pre and post-stimulus). RESULTS Interaction was found between the group and condition factors for Fp1, F4 and F3. We observed a main effect of moment and condition for the Fp2, F8 and Fz electrodes. CONCLUSION We concluded that drugs may interfere in sensorimotor processes, such as in the performance of tasks carried out in an unpredictable scenario.
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Affiliation(s)
- Danielle Aprigio
- Instituto de Psiquiatria, Neurofisiologia e Neuropsicologia da Atenção, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Washington Adolfo
- Instituto de Psiquiatria, Neurofisiologia e Neuropsicologia da Atenção, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Juliana Bittencourt
- Instituto de Psiquiatria, Neurofisiologia e Neuropsicologia da Atenção, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Mariana Gongora
- Instituto de Psiquiatria, Mapeamento Cerebral e Integração Sensorial Motor, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Silmar Teixeira
- Mapeamento Cerebral e Laboratório de Plasticidade, Universidade Federal do Piauí, Parnaíba, PI, Brazil
| | | | - Henning Budde
- Medical School Hamburg, Faculty of Human Sciences, Hamburg, Germany
| | - Mauricio Cagy
- Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Pedro Ribeiro
- Instituto de Psiquiatria, Mapeamento Cerebral e Integração Sensorial Motor, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Bruna Velasques
- Instituto de Psiquiatria, Neurofisiologia e Neuropsicologia da Atenção, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Rabaeys H, Bijleveld HA, Devroey D. Influence of Methylphenidate on the Frequency of Stuttering. Ann Pharmacother 2015; 49:1096-104. [DOI: 10.1177/1060028015596415] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background: Recently, a case report described a decrease in frequency of stuttering after intake of methylphenidate (MPH). Objective: This study was undertaken to investigate if this effect could again be reproduced in a population of young healthy male adult persons with developmental stuttering. Methods: A double-blind randomized crossover trial, with a 2-week washout period, including 15 Dutch-speaking young healthy persons with developmental stuttering, assessed the effects of a single dose of 20 mg MPH compared with placebo on stuttering. Dependent and 1-sample t tests were used to detect significant differences. The end point was the number of stutter moments and self-perceived improvement. Results: MPH yielded a significant decrease in the number of stutter moments when reading and speaking ( P = 0.002), which was not the case with placebo ( P = 0.090). There was a significant improvement from baseline after intake of MPH as compared with placebo ( P = 0.003). Self-perceived improvement with MPH was not significantly better as compared with placebo ( P = 0.28). Conclusions: This study showed that the participants had an objective statistically significant decrease in the frequency of stuttering with MPH, and this was not the case with placebo. This was also the case for a reduction in stutter moments when reading out loud and speaking spontaneously. However, this result was not subjectively perceived by the participants.
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90
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Cohen YG, Segev RW, Shlafman N, Novack V, Ifergane G. Methylphenidate use among medical students at Ben-Gurion University of the Negev. J Neurosci Rural Pract 2015; 6:320-5. [PMID: 26167012 PMCID: PMC4481783 DOI: 10.4103/0976-3147.158749] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Introduction: Methylphenidate is a psychotropic agent commonly used for the treatment of attention deficit disorder with or without hyperactivity and narcolepsy in children and adults. The awareness to attention deficit disorder as well as the non-medical use of methylphenidate for cognitive enhancement has increased during the past years. Objectives: To evaluate the medical and non-medical use of methylphenidate among medical students in the Ben-Gurion University of the Negev. Materials and Methods: Medical students were asked to report methylphenidate use, symptoms and diagnosis of attention deficit disorder using a structured questionnaire. Results: A total of 229 students participated in the study, out of which 105 (45.9%) were in the pre-clinical years of medical school. Twenty-two students (9.6%) were previously diagnosed with attention deficit disorder. Lifelong use of methylphenidate was reported by 39 (17%) students, while 31 students (13.5%) reported using methylphenidate during the preceding 12 month. In the beginning of medical school, only 7% of the students used methylphenidate, most of them began using it during pre-clinical academic years. Discussion: High rates of attention deficit disorder compared to the general population were reported by medical students. The rate of methylphenidate use is similar to recent report from a US medical school, and is considerably higher than in college students population. Conclusions: Many medical students are using methylphenidate without a medical indication. Further study is needed to evaluate the effect of methylphenidate on academic performance of healthy adults.
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Affiliation(s)
- Yael Givon Cohen
- Department of Neurology, Soroka University Medical Center, and Faculty of Health Sciences Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Renana Wilkof Segev
- Department of Clinical Research Center, Soroka University Medical Center, and Faculty of Health Sciences Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Nurit Shlafman
- Department of Chief of Mental Health Services, Southern Region, Maccabi Health Services, Israel
| | - Victor Novack
- Department of Clinical Research Center, Soroka University Medical Center, and Faculty of Health Sciences Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Gal Ifergane
- Department of Neurology, Soroka University Medical Center, and Faculty of Health Sciences Ben-Gurion University of the Negev, Beer-Sheva, Israel
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91
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Simchon Tenenbaum Y, Weizman A, Rehavi M. The Impact of Chronic Early Administration of Psychostimulants on Brain Expression of BDNF and Other Neuroplasticity-Relevant Proteins. J Mol Neurosci 2015; 57:231-42. [PMID: 26152882 DOI: 10.1007/s12031-015-0611-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 06/26/2015] [Indexed: 01/08/2023]
Abstract
ABSRACT Frequently, healthy individuals, children, and students are using stimulants to treat attention deficit hyperactivity disorder (ADHD)-like symptoms or to enhance cognitive capacity, attention and concentration. Methylphenidate, the most common treatment for ADHD, similarly to cocaine, blocks the dopamine reuptake, leading to increase in dopamine level in the synaptic cleft. Brain-derived neurotrophic factor (BDNF) and other neuroplasticity-relevant proteins have a major role in cellular plasticity during development and maturation of the brain. Young Sprague Dawley rats (postnatal days (PND) 14) were treated chronically with either cocaine or methylphenidate. The rats were examined behaviorally and biochemically at several time points (PND 35, 56, 70, and 90). We found age-dependent, but stimulant-independent, alterations in the mRNA expression levels of microtubule-associated protein tau, doublecortin, and synaptophysin. The PND 90 rats, treated with methylphenidate at an early age, exhibited increased BDNF protein levels in the prefrontal cortex compared to the saline-treated group. Despite the treatment effects at the biochemical level, cocaine and methylphenidate treatments at an early age had only minor effects on the behavioral parameters measured at older ages. The biochemical alterations may reflect neuroprotective or neuroplastic effects of chronic methylphenidate treatment at an early age.
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Affiliation(s)
- Yaarit Simchon Tenenbaum
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel-Aviv University, Ramat Aviv, 69978, Tel-Aviv, Israel
| | - Abraham Weizman
- Research Unit, Geha Mental Health Center and Felsenstein Medical Research Center, Petah-Tikva, Israel
| | - Moshe Rehavi
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel-Aviv University, Ramat Aviv, 69978, Tel-Aviv, Israel. .,The Dr. Miriam and Sheldon G. Adelson Chair and Center for the Biology of Addictive Diseases, Tel-Aviv, Israel.
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92
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Behavioral and cognitive effects of tyrosine intake in healthy human adults. Pharmacol Biochem Behav 2015; 133:1-6. [DOI: 10.1016/j.pbb.2015.03.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 02/20/2015] [Accepted: 03/12/2015] [Indexed: 11/21/2022]
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Heidbreder R. ADHD symptomatology is best conceptualized as a spectrum: a dimensional versus unitary approach to diagnosis. ACTA ACUST UNITED AC 2015; 7:249-69. [PMID: 25957598 DOI: 10.1007/s12402-015-0171-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 04/18/2015] [Indexed: 12/19/2022]
Abstract
The aim of this paper is to build a case for the utility of conceptualizing ADHD, not as a unitary disorder that contains several subtypes, but rather as a marker of impairment in attention and/or impulsivity that can be used to identify one of several disorders belonging to a spectrum. The literature will be reviewed to provide an overview of what is known about ADHD in terms of heterogeneity in symptomatology, neuropsychology, neurobiology, as well as comorbidity with other diseases and treatment options. The data from these areas of research will be critically analyzed to support the construct of a spectrum of disorders that can capture the great variability that exists between individuals with ADHD and can discriminate between separate disorders that manifest similar symptoms. The symptoms associated with ADHD can be viewed as dimensional markers that point to a spectrum of related disorders that have as part of their characteristics impairments of attention and impulsivity. The spectrum can accommodate symmetrically and asymmetrically comorbid psychiatric disorders associated with ADHD as well as the wide heterogeneity known to be a part of the ADHD disorder. Individuals presenting with impairments associated with ADHD should be treated as having a positive marker for a spectrum disorder that has as part of its characteristics impairments of attention and/or impulsivity. The identification of impairment in attention and/or impulsivity should be a starting point for further testing rather than being an endpoint of diagnosis that results in pharmacological treatment that may or may not be the optimal therapy. Rather than continuing to attribute a large amount of heterogeneity in symptom presentation as well as a high degree of symmetric and asymmetric comorbidity to a single disorder, clinical evaluation should turn to the diagnosis of the type of attentional deficit and/or impulsivity an individual has in order to colocate the individual's disorder on a spectrum that captures the heterogeneity in symptomatology, the symmetrical and asymmetrical comorbidity, as well as subthreshold presentation and other variants often worked into the disorder of ADHD. The spectrum model can accommodate not only the psychophysiological profiles of patients, but is also consistent with what is known about the functional heterogeneity of the prefrontal cortex as well as the construct that cognitive processes are supported by overlapping and collaborative networks.
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Affiliation(s)
- Rebeca Heidbreder
- PsychResearchCenter, LLC, 3669 Michaux Mill Drive, Powhatan, VA, 23139, USA.
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Abstract
Psychostimulants are a diverse group of substances with their main psychomotor effects resembling those of amphetamine, methamphetamine, cocaine, or cathinone. Due to their potential as drugs of abuse, recreational use of most of these substances is illegal since 1971 Convention on Psychotropic Substances. In recent years, new psychoactive substances have emerged mainly as synthetic cathinones with new molecules frequently complementing the list. Psychostimulant related movement disorders are a known entity often seen in emergency rooms around the world. These admissions are becoming more frequent as are fatalities associated with drug abuse. Still the legal constraints of the novel synthetic molecules are bypassed. At the same time, chronic and permanent movement disorders are much less frequently encountered. These disorders frequently manifest as a combination of movement disorders. The more common symptoms include agitation, tremor, hyperkinetic and stereotypical movements, cognitive impairment, and also hyperthermia and cardiovascular dysfunction. The pathophysiological mechanisms behind the clinical manifestations have been researched for decades. The common denominator is the monoaminergic signaling. Dopamine has received the most attention but further research has demonstrated involvement of other pathways. Common mechanisms linking psychostimulant use and several movement disorders exist.
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Affiliation(s)
- Andres Asser
- Department of Neurology and Neurosurgery, University of Tartu , Tartu , Estonia
| | - Pille Taba
- Department of Neurology and Neurosurgery, University of Tartu , Tartu , Estonia
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Methylphenidate effects on brain activity as a function of SLC6A3 genotype and striatal dopamine transporter availability. Neuropsychopharmacology 2015; 40:736-45. [PMID: 25220215 PMCID: PMC4289963 DOI: 10.1038/npp.2014.240] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 07/29/2014] [Accepted: 08/04/2014] [Indexed: 12/31/2022]
Abstract
We pharmacologically challenged catecholamine reuptake, using methylphenidate, to investigate its effects on brain activity during a motor response inhibition task as a function of the 3'-UTR variable number of tandem repeats (VNTR) polymorphism of the dopamine transporter (DAT) gene (SLC6A3) and the availability of DATs in the striatum. We measured the cerebral hemodynamic response of 50 healthy males during a Go/No-Go task, a measure of cognitive control, under the influence of 40 mg methylphenidate and placebo using 3T functional magnetic resonance imaging. Subjects were grouped into 9-repeat (9R) carriers and 10/10 homozygotes on the basis of the SLC6A3 VNTR. During successful no-go trials compared with oddball trials, methylphenidate induced an increase of blood oxygen level-dependent (BOLD) signal for carriers of the SLC6A3 9R allele but a decrease in 10/10 homozygotes in a thalamocortical network. The same pattern was observed in caudate and inferior frontal gyrus when successful no-go trials were compared with successful go trials. We additionally investigated in a subset of 35 participants whether baseline striatal DAT availability, ascertained with (123)I-FP-CIT single photon emission computed tomography, predicted the amount of methylphenidate-induced change in hemodynamic response or behavior. Striatal DAT availability was nominally greater in 9R carriers compared with 10/10 homozygotes (d=0.40), in line with meta-analyses, but did not predict BOLD or behavioral changes following MPH administration. We conclude that the effects of acute MPH administration on brain activation are dependent on DAT genotype, with 9R carriers showing enhanced BOLD following administration of a prodopaminergic compound.
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Kollins SH, Schoenfelder EN, English JS, Holdaway A, Van Voorhees E, O'Brien BR, Dew R, Chrisman AK. An exploratory study of the combined effects of orally administered methylphenidate and delta-9-tetrahydrocannabinol (THC) on cardiovascular function, subjective effects, and performance in healthy adults. J Subst Abuse Treat 2014; 48:96-103. [PMID: 25175495 DOI: 10.1016/j.jsat.2014.07.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 07/22/2014] [Accepted: 07/30/2014] [Indexed: 02/06/2023]
Abstract
Methylphenidate (MPH) is commonly prescribed for the treatment of Attention Deficit Hyperactivity Disorder (ADHD), and is often used illicitly by young adults. Illicit users often coadminister MPH with marijuana. Little is known about physiologic and subjective effects of these substances used in combination. In this double-blind, cross-over experiment, sixteen healthy adult subjects free from psychiatric illness (including ADHD) and reporting modest levels of marijuana use participated in 6 experimental sessions wherein all combinations of placebo or 10mg oral doses of delta-9-tetrahydocannibinol (THC); and 0mg, 10mg and 40 mg of MPH were administered. Sessions were separated by at least 48 hours. Vital signs, subjective effects, and performance measure were collected. THC and MPH showed additive effects on heart rate and rate pressure product (e.g., peak heart rate for 10mg THC+0mg, 10mg, and 40 mg MPH=89.1, 95.9, 102.0 beats/min, respectively). Main effects of THC and MPH were also observed on a range of subjective measures of drug effects, and significant THC dose × MPH dose interactions were found on measures of "Feel Drug," "Good Effects," and "Take Drug Again." THC increased commission errors on a continuous performance test (CPT) and MPH reduced reaction time variability on this measure. Effects of THC, MPH, and their combination were variable on a measure of working memory (n-back task), though in general, MPH decreased reaction times and THC mitigated these effects. These results suggest that the combination of low to moderate doses of MPH and THC produces unique effects on cardiovascular function, subjective effects and performance measures.
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Affiliation(s)
- Scott H Kollins
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, Durham, NC.
| | | | - Joseph S English
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, Durham, NC
| | - Alex Holdaway
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, Durham, NC
| | | | - Benjamin R O'Brien
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, Durham, NC
| | - Rachel Dew
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, Durham, NC
| | - Allan K Chrisman
- Department of Psychiatry and Behavioral Science, Duke University School of Medicine, Durham, NC
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