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Noback M, Bhakta SG, Talledo JA, Kotz JE, Benster L, Roberts BZ, Nungaray JA, Light GA, Swerdlow NR, Brigman JL, Cavanagh JF, Young JW. Amphetamine increases motivation of humans and mice as measured by breakpoint, but does not affect an Electroencephalographic biomarker. COGNITIVE, AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2024; 24:269-278. [PMID: 38168850 PMCID: PMC11060428 DOI: 10.3758/s13415-023-01150-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/15/2023] [Indexed: 01/05/2024]
Abstract
Translation of drug targets from preclinical studies to clinical trials has been aided by cross-species behavioral tasks, but evidence for brain-based engagement during task performance is still required. Cross-species progressive ratio breakpoint tasks (PRBTs) measure motivation-related behavior and are pharmacologically and clinically sensitive. We recently advanced elevated parietal alpha power as a cross-species electroencephalographic (EEG) biomarker of PRBT engagement. Given that amphetamine increases breakpoint in mice, we tested its effects on breakpoint and parietal alpha power in both humans and mice. Twenty-three healthy participants performed the PRBT with EEG after amphetamine or placebo in a double-blind design. C57BL/6J mice were trained on PRBT with EEG (n = 24) and were treated with amphetamine or vehicle. A second cohort of mice was trained on PRBT without EEG (n = 40) and was treated with amphetamine or vehicle. In humans, amphetamine increased breakpoint. In mice, during concomitant EEG, 1 mg/kg of amphetamine significantly decreased breakpoint. In cohort 2, however, 0.3 mg/kg of amphetamine increased breakpoint consistent with human findings. Increased alpha power was observed in both species as they reached breakpoint, replicating previous findings. Amphetamine did not affect alpha power in either species. Amphetamine increased effort in humans and mice. Consistent with previous reports, elevated parietal alpha power was observed in humans and mice as they performed the PRBT. Amphetamine did not affect this EEG biomarker of effort. Hence, these findings support the pharmacological predictive validity of the PRBT to measure effort in humans and mice and suggest that this EEG biomarker is not directly reflective of amphetamine-induced changes in effort.
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Affiliation(s)
- Michael Noback
- Department of Psychiatry, University of California, San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA
| | - Savita G Bhakta
- Department of Psychiatry, University of California, San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA
| | - Jo A Talledo
- Department of Psychiatry, University of California, San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA
| | - Juliana E Kotz
- Department of Psychiatry, University of California, San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA
| | - Lindsay Benster
- Department of Psychiatry, University of California, San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA
| | - Benjamin Z Roberts
- Department of Psychiatry, University of California, San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA
| | - John A Nungaray
- Department of Psychiatry, University of California, San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA
| | - Gregory A Light
- Department of Psychiatry, University of California, San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA
- Research Service MIRECC, VISN 22, Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
| | - Neal R Swerdlow
- Department of Psychiatry, University of California, San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA
| | - Jonathan L Brigman
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - James F Cavanagh
- Psychology Department, University of New Mexico, Albuquerque, NM, USA
| | - Jared W Young
- Department of Psychiatry, University of California, San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA.
- Research Service MIRECC, VISN 22, Veterans Affairs San Diego Healthcare System, San Diego, CA, USA.
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Swerdlow NR, Bhakta SG, Talledo J, Benster L, Kotz J, Vinogradov S, Molina JL, Light GA. Auditory discrimination and frequency modulation learning in schizophrenia patients: amphetamine within-subject dose response and time course. Psychol Med 2023; 53:140-148. [PMID: 33849683 PMCID: PMC8514598 DOI: 10.1017/s0033291721001239] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 01/24/2021] [Revised: 03/11/2021] [Accepted: 03/17/2021] [Indexed: 11/17/2022]
Abstract
BACKGROUND Auditory frequency modulation learning ('auditory learning') is a key component of targeted cognitive training (TCT) for schizophrenia. TCT can be effective in enhancing neurocognition and function in schizophrenia, but such gains require significant time and effort and elude many patients. METHODS As a strategy to increase and/or accelerate TCT-induced clinical gains, we tested the dose- and time-course effects of the pro-attentional drug, amphetamine (AMPH; placebo, 2.5, 5 or 10 mg po; within-subject double-blind, order balanced) on auditory learning in schizophrenia patients [n = 32; M:F = 19:13; age 42.0 years (24-55)]. To understand predictors and/or mechanisms of AMPH-enhanced TCT, we also measured auditory fidelity (words-in-noise (WIN), quick speech-in-noise (QuickSIN)) and neurocognition (MATRICS comprehensive cognitive battery (MCCB)). Some measures were also acquired from age-matched healthy subjects (drug free; n = 10; M:F = 5:5). RESULTS Patients exhibited expected deficits in neurocognition. WIN and QuickSIN performance at low signal intensities was impaired in patients with low v. high MCCB attention/vigilance (A/V) scores; these deficits were corrected by AMPH, maximally at 2.5-5 mg (d's = 0.79-1.29). AMPH also enhanced auditory learning, with maximal effects at 5 mg (d = 0.93), and comparable effects 60 and 210 min post pill. 'Pro-learning' effects of AMPH and AMPH-induced gains in auditory fidelity were most evident in patients with low MCCB A/V scores. CONCLUSIONS These findings advance our understanding of the impact of pro-attentional interventions on auditory information processing and suggest dose- and time-course parameters for studies that assess the ability of AMPH to enhance the clinical benefits of TCT in schizophrenia patients.
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Affiliation(s)
- Neal R. Swerdlow
- Department of Psychiatry, School of Medicine, University of California, San Diego, USA
| | - Savita G. Bhakta
- Department of Psychiatry, School of Medicine, University of California, San Diego, USA
| | - Jo Talledo
- Department of Psychiatry, School of Medicine, University of California, San Diego, USA
| | - Lindsay Benster
- Department of Psychiatry, School of Medicine, University of California, San Diego, USA
| | - Juliana Kotz
- Department of Psychiatry, School of Medicine, University of California, San Diego, USA
| | - Sophia Vinogradov
- Department of Psychiatry, School of Medicine, University of Minnesota, USA
| | - Juan L. Molina
- Department of Psychiatry, School of Medicine, University of California, San Diego, USA
| | - Gregory A. Light
- Department of Psychiatry, School of Medicine, University of California, San Diego, USA
- VISN-22 Mental Illness Research Education and Clinical Center, VA San Diego Healthcare System, San Diego, CA, USA
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Strzelecki A, Weafer J, Stoops WW. Human behavioral pharmacology of stimulant drugs: An update and narrative review. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2022; 93:77-103. [PMID: 35341574 DOI: 10.1016/bs.apha.2021.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Stimulant use disorders present an enduring public health concern. Chronic stimulant use is associated with a range of health problems, with notable increases in stimulant overdose that disproportionately affect marginalized populations. With these persistent problems, it is important to understand the behavioral and pharmacological factors that contribute to stimulant use in humans. The purpose of this chapter is to provide an update and narrative review on recent human laboratory research that has evaluated the behavioral pharmacology of stimulant drugs. We focus on two prototypic stimulants: cocaine as a prototype monoamine reuptake inhibitor and d-amphetamine as a prototype monoamine releaser. As such, placebo controlled human laboratory studies that involved administration of doses of cocaine or d-amphetamine and were published in peer reviewed journals within the last 10 years (i.e., since 2011) are reviewed. Primary outcomes from these studies are subjective effects, reinforcing effects, cognitive/behavioral effects, and discriminative stimulus effects. Both cocaine and d-amphetamine produce classical stimulant-like behavioral effects (e.g., increase positive subjective effects, function as reinforcers), but there are notable gaps in the literature including understanding sex differences in response to stimulant drugs, cognitive-behavioral effects of stimulants, and influence of use history (e.g., relatively drug naïve vs drug experienced) on stimulant effects.
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Affiliation(s)
- Ashley Strzelecki
- University of Kentucky, Department of Psychology, Lexington, KY, United States
| | - Jessica Weafer
- University of Kentucky, Department of Psychology, Lexington, KY, United States
| | - William W Stoops
- University of Kentucky, Department of Psychology, Lexington, KY, United States; University of Kentucky, Department of Behavioral Science, Lexington, KY, United States; University of Kentucky, Department of Psychiatry, Lexington, KY, United States; University of Kentucky, Center on Drug and Alcohol Research, Lexington, KY, United States.
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Bhakta SG, Cavanagh JF, Talledo JA, Kotz JE, Benster L, Roberts BZ, Nungaray JA, Brigman JL, Light GA, Swerdlow NR, Young JW. EEG reveals that dextroamphetamine improves cognitive control through multiple processes in healthy participants. Neuropsychopharmacology 2022; 47:1029-1036. [PMID: 35042948 PMCID: PMC8938448 DOI: 10.1038/s41386-021-01257-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/28/2021] [Accepted: 12/09/2021] [Indexed: 12/29/2022]
Abstract
The poor translatability between preclinical and clinical drug trials has limited pro-cognitive therapeutic development. Future pro-cognitive drug trials should use translatable cross-species cognitive tasks with biomarkers (1) relevant to specific cognitive constructs, and (2) sensitive to drug treatment. Here, we used a difficulty-modulated variant of a cross-species cognitive control task with simultaneous electroencephalography (EEG) to identify neurophysiological biomarkers sensitive to the pro-cognitive effects of dextroamphetamine (d-amp) (10 or 20 mg) in healthy adults (n = 23), in a randomized, placebo-controlled, counterbalanced, double blind, within-subject study, conducted across three test days each separated by one week. D-amp boosted d-prime, sped reaction time, and increased frontal P3a amplitude to non-target correct rejections independent of task difficulty. Task difficulty did however, moderate d-amp effects on EEG during target performance. D-amp suppressed frontal theta power during easy target responses which negatively correlated with drug-induced improvement in hit rate while d-amp-induced changes in P3b amplitude during hard target trials strongly correlated with drug-induced improvement in hit rate. In summary, d-amp affected both behavioral and neurophysiological measures of cognitive control elements. Under low-demand, d-amp diminished cognitive control by suppressing theta, yet under high-demand it boosted control in concert with higher P3b amplitudes. These findings thus appear to reflect a gain-sharpening effect of d-amp: during high-demand processes were boosted while during low-demand processes were neglected. Future studies will use these neurophysiological measures of cognitive control as biomarkers to predict d-amp sensitivity in people with cognitive control deficits, including schizophrenia.
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Affiliation(s)
- Savita G Bhakta
- Department of Psychiatry, University of California, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093, USA
| | - James F Cavanagh
- Psychology Department, University of New Mexico, Albuquerque, NM, USA
| | - Jo A Talledo
- Department of Psychiatry, University of California, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093, USA
| | - Juliana E Kotz
- Department of Psychiatry, University of California, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093, USA
| | - Lindsay Benster
- Department of Psychiatry, University of California, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093, USA
| | - Benjamin Z Roberts
- Department of Psychiatry, University of California, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093, USA
| | - John A Nungaray
- Department of Psychiatry, University of California, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093, USA
| | - Jonathan L Brigman
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA
| | - Gregory A Light
- Department of Psychiatry, University of California, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093, USA
- Desert Pacific Mental Illness Research, Education, and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA
| | - Neal R Swerdlow
- Department of Psychiatry, University of California, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093, USA
| | - Jared W Young
- Department of Psychiatry, University of California, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093, USA.
- Desert Pacific Mental Illness Research, Education, and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, USA.
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Spiros A, Geerts H. Toward Predicting Impact of Common Genetic Variants on Schizophrenia Clinical Responses With Antipsychotics: A Quantitative System Pharmacology Study. Front Neurosci 2021; 15:738903. [PMID: 34658776 PMCID: PMC8511786 DOI: 10.3389/fnins.2021.738903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 09/06/2021] [Indexed: 11/13/2022] Open
Abstract
CNS disorders are lagging behind other indications in implementing genotype-dependent treatment algorithms for personalized medicine. This report uses a biophysically realistic computer model of an associative and dorsal motor cortico-striatal-thalamo-cortical loop and a working memory cortical model to investigate the pharmacodynamic effects of COMTVal158Met rs4680, 5-HTTLPR rs 25531 s/L and D2DRTaq1A1 genotypes on the clinical response of 7 antipsychotics. The effect of the genotypes on dopamine and serotonin dynamics and the level of target exposure for the drugs was calibrated from PET displacement studies. The simulations suggest strong gene-gene pharmacodynamic interactions unique to each antipsychotic. For PANSS Total, the D2DRTaq1 allele has the biggest impact, followed by the 5-HTTLPR rs25531. The A2A2 genotype improved efficacy for all drugs, with a more complex outcome for the 5-HTTLPR rs25531 genotype. Maximal range in PANSS Total for all 27 individual combinations is 3 (aripiprazole) to 5 points (clozapine). The 5-HTTLPR L/L with aripiprazole and risperidone and the D2DRTaq1A2A2 allele with haloperidol, clozapine and quetiapine reduce the motor side-effects with opposite effects for the s/s genotype. The COMT genotype has a limited effect on antipsychotic effect and EPS. For cognition, the COMT MM 5-HTTLPR L/L genotype combination has the best performance for all antipsychotics, except clozapine. Maximal difference is 25% of the total dynamic range in a 2-back working memory task. Aripiprazole is the medication that is best suited for the largest number of genotype combinations (10) followed by Clozapine and risperidone (6), haloperidol and olanzapine (3) and quetiapine and paliperidone for one genotype. In principle, the platform could identify the best antipsychotic treatment balancing efficacy and side-effects for a specific individual genotype. Once the predictions of this platform are validated in a clinical setting the platform has potential to support rational personalized treatment guidance in clinical practice.
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Affiliation(s)
- Athan Spiros
- In Silico Biosciences, Berwyn, PA, United States
| | - Hugo Geerts
- In Silico Biosciences, Berwyn, PA, United States.,Certara QSP, Canterbury, United Kingdom
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Narayan AJ, Aitken B, Downey LA, Hayley AC. The effects of amphetamines alone and in combination with alcohol on functional neurocognition: A systematic review. Neurosci Biobehav Rev 2021; 131:865-881. [PMID: 34626687 DOI: 10.1016/j.neubiorev.2021.10.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/01/2021] [Accepted: 10/02/2021] [Indexed: 02/05/2023]
Abstract
Due to their desirable synergistic and/or additive pharmacological effects, amphetamines and alcohol are frequently co-consumed; yet, their combined functional neurocognitive effects remain poorly defined. The PubMed, Scopus, SafetyLit, CINAHL Complete and Medline databases were examined from inception to December 2020. Study selection, data extraction and Cochrane Risk of Bias (RoB2) assessments were conducted according to PRISMA guidelines, and the review was registered on the PROSPERO database (CRD42020189168). A total of 39 full-text articles were included which examined the effects of six amphetamine analogues alone (n = 33) and in combination with alcohol (n = 6) on measures of attention, working memory and reaction time. Amphetamine alone produced limited inverted-U shaped improvement in select behavioural domains, particularly among poor baseline performers. Combined amphetamine and alcohol impaired psychomotor speed and motor control comparable to alcohol alone, and co-consumption with high doses of alcohol (0.08 %BAC) protracted behavioural deficits. Co-consumption of amphetamine with high doses of alcohol impairs response discrimination and psychomotor speed, and their combination is not sufficient to overcome alcohol-induced motor impairment.
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Affiliation(s)
- Andrea J Narayan
- Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia
| | - Blair Aitken
- Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia
| | - Luke A Downey
- Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia; Institute for Breathing and Sleep, Austin Health, Melbourne, Australia
| | - Amie C Hayley
- Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, Australia; Institute for Breathing and Sleep, Austin Health, Melbourne, Australia.
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7
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Geerts H, Roberts P, Spiros A. Exploring the relation between BOLD fMRI and cognitive performance using a computer-based quantitative systems pharmacology model: Applications to the COMTVAL158MET genotype and ketamine. Eur Neuropsychopharmacol 2021; 50:12-22. [PMID: 33951587 DOI: 10.1016/j.euroneuro.2021.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/14/2021] [Accepted: 04/06/2021] [Indexed: 10/21/2022]
Abstract
BOLD fMRI is increasingly used mostly in an observational way to probe the effect of genotypes or therapeutic intervention in normal and diseased subjects. We use a mechanism-based quantitative systems pharmacology computer model of a human cortical microcircuit, previously calibrated for the 2-back working memory paradigm, adding established biophysical principles, of glucose metabolism, oxygen consumption, neurovascular effects and the paramagnetic impact on blood oxygen levels to calculate a readout for the voxel-based BOLD fMRI signal. The objective was to study the effect of the Catechol-O-methyl Transferase Val158Met (COMT) genotype on performance and BOLD fMRI. While the simulation suggests that on average virtual COMTVV genotype subjects perform worse, subjects with lower GABA, lower 5-HT3 and higher 5-HT1A activation can improve cognitive performance to the level of COMTMM subjects but at the expense of higher BOLD fMRI signal. In a schizophrenia condition, increased NMDA, GABA tone and noise levels, and lower D1R activity can improve cognitive outcome with greater BOLD fMRI signal in COMT Val-carriers. We further generate hypotheses about why ketamine in healthy controls increases the BOLD fMRI signal but reduces cognitive performance. These simulations suggest a strong non-linear relationship between BOLD fMRI signal and cognitive performance. When validated, this mechanistic approach can be useful for moving beyond the descriptive nature of BOLD fMRI imaging and supporting the proper interpretation of imaging biomarkers in CNS disorders.
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Affiliation(s)
- Hugo Geerts
- In Silico Biosciences, Hugo Geerts, 686 Westwind Dr, Berwyn, PA 19312, United States.
| | - Patrick Roberts
- In Silico Biosciences, Hugo Geerts, 686 Westwind Dr, Berwyn, PA 19312, United States
| | - Athan Spiros
- In Silico Biosciences, Hugo Geerts, 686 Westwind Dr, Berwyn, PA 19312, United States
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8
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Young JW, Roberts BZ, Breier M, Swerdlow NR. Amphetamine improves rat 5-choice continuous performance test (5C-CPT) irrespective of concurrent low-dose haloperidol treatment. Psychopharmacology (Berl) 2020; 237:1959-1972. [PMID: 32318751 DOI: 10.1007/s00213-020-05511-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 03/26/2020] [Indexed: 12/22/2022]
Abstract
RATIONALE Cognitive dysfunction mediates functional impairment in patients with schizophrenia, necessitating the timely development of pro-cognitive therapeutics. An important initial step in this process is to establish what, if any, pro-cognitive agents and associated mechanisms can be identified using cross-species translational paradigms. For example, attentional deficits-a core feature of schizophrenia-can be measured across species using the 5-choice continuous performance test (5C-CPT). The psychostimulant, amphetamine, improves human and rodent 5C-CPT performance. OBJECTIVE Here, we tested whether amphetamine would similarly improve 5C-CPT performance in the presence of dopamine D2 receptor blockade, since pro-cognitive treatments in schizophrenia would virtually always be used in conjunction with D2 receptor antagonists. METHODS We established the dose-response effects of amphetamine (0, 0.1, 0.3, or 1.0 mg/kg) and haloperidol (0, 3.2, 10, or 32 μg/kg) on 5C-CPT performance in Long Evans rats, and then tested an amphetamine (0.3 mg/kg) × haloperidol (10 μg/kg) interaction; the low dose was chosen because higher doses exerted deleterious non-specific effects on performance. RESULTS Amphetamine improved 5C-CPT performance in poorly performing rats by increasing target detection, independent of haloperidol pretreatment. CONCLUSIONS The pro-attentional effects of amphetamine were most likely mediated by dopamine release at D1-family receptors, since they persisted in the presence of acute D2 blockade. Alternative explanations for these findings are also discussed, as are their potential implications for future pro-cognitive therapeutics in schizophrenia.
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Affiliation(s)
- Jared W Young
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA, 92093-0804, USA. .,Research Service, VA San Diego Healthcare System, San Diego, CA, USA.
| | - Benjamin Z Roberts
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA, 92093-0804, USA
| | - Michelle Breier
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA, 92093-0804, USA
| | - Neal R Swerdlow
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA, 92093-0804, USA
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Kuypers K, Verkes RJ, van den Brink W, van Amsterdam J, Ramaekers JG. Intoxicated aggression: Do alcohol and stimulants cause dose-related aggression? A review. Eur Neuropsychopharmacol 2020; 30:114-147. [PMID: 29941239 DOI: 10.1016/j.euroneuro.2018.06.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 05/23/2018] [Accepted: 06/02/2018] [Indexed: 12/30/2022]
Abstract
RATIONALE Violence and drug use are significant public health challenges that are strongly linked. It is known that alcohol plays a major role in the causation of unnatural deaths and that stimulants like cocaine and amphetamine are often implicated in aggressive acts or violence. However, a clear causal relationship between these substances and aggression, and more specifically a blood concentration threshold at which intoxicated aggression emerges is lacking. In case of a crime and subsequent law enforcement, knowledge about dose-response relationships could be of pivotal importance when evaluating the role of alcohol and drugs in aggressive offences. AIMS The present review aimed to determine whether there is a causal relation between intoxication with these psychoactive substances and aggression, and to define blood concentration thresholds above which these substances elicit aggression. METHODS Empirical articles published between 2013 and 2017 and review papers containing the predefined search strings were identified through searches in the PubMed and Embase databases and additional reference list searches. The complete search query yielded 1578 publications. Initially all articles were manually screened by title and abstract. Articles with irrelevant titles, given the selected search terms and review aims were discarded. Remaining articles were carefully studied and those that did not comply with the main objectives of this review were discarded. At the end of this process, 167 titles were found eligible for review. FINDINGS AND CONCLUSION While placebo-controlled experimental studies clearly showed a causal link between alcohol and aggression, it is evident that such a link has not yet been established for cocaine and amphetamines. In case of alcohol, it is clear that there are various individual and contextual factors that may contribute to the occurrence of an aggressive act during intoxication. A clear threshold blood alcohol concentration has not been defined yet for alcohol, but a statistically significant increase of aggression has been demonstrated at a dose of 0.75 g/kg and higher. Future studies into intoxicated aggression should include multiple doses of alcohol and stimulants and take into account individual and contextual factors.
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Affiliation(s)
- Kpc Kuypers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, PO Box 616, 6200 MD, Maastricht, The Netherlands.
| | - R J Verkes
- Radboud UMC, Psychiatry, Radboud University, Nijmegen, The Netherlands
| | - W van den Brink
- AMC Psychiatry, University of Amsterdam, Amsterdam, The Netherlands
| | | | - J G Ramaekers
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology & Neuroscience, Maastricht University, PO Box 616, 6200 MD, Maastricht, The Netherlands
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Dresler M, Sandberg A, Bublitz C, Ohla K, Trenado C, Mroczko-Wąsowicz A, Kühn S, Repantis D. Hacking the Brain: Dimensions of Cognitive Enhancement. ACS Chem Neurosci 2019; 10:1137-1148. [PMID: 30550256 PMCID: PMC6429408 DOI: 10.1021/acschemneuro.8b00571] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 12/14/2018] [Indexed: 12/11/2022] Open
Abstract
In an increasingly complex information society, demands for cognitive functioning are growing steadily. In recent years, numerous strategies to augment brain function have been proposed. Evidence for their efficacy (or lack thereof) and side effects has prompted discussions about ethical, societal, and medical implications. In the public debate, cognitive enhancement is often seen as a monolithic phenomenon. On a closer look, however, cognitive enhancement turns out to be a multifaceted concept: There is not one cognitive enhancer that augments brain function per se, but a great variety of interventions that can be clustered into biochemical, physical, and behavioral enhancement strategies. These cognitive enhancers differ in their mode of action, the cognitive domain they target, the time scale they work on, their availability and side effects, and how they differentially affect different groups of subjects. Here we disentangle the dimensions of cognitive enhancement, review prominent examples of cognitive enhancers that differ across these dimensions, and thereby provide a framework for both theoretical discussions and empirical research.
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Affiliation(s)
- Martin Dresler
- Donders Institute for Brain, Cognition and Behaviour , Radboud University Medical Centre , Nijmegen 6525 EN , The Netherlands
| | - Anders Sandberg
- Future of Humanity Institute , Oxford University , Oxford OX1 1PT , United Kingdom
| | | | - Kathrin Ohla
- Institute of Neuroscience and Medicine, Cognitive Neuroscience (INM3) , Forschungszentrum Jülich , Jülich 52428 , Germany
| | - Carlos Trenado
- Institute of Clinical Neuroscience and Medical Psychology , Heinrich Heine University Düsseldorf , Düsseldorf 40225 , Germany
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors , TU Dortmund , Dortmund 44139 , Germany
| | | | - Simone Kühn
- Max Planck Institute for Human Development , Berlin 14195 , Germany
- Department of Psychiatry and Psychotherapy , University Clinic Hamburg Eppendorf , Hamburg 20246 , Germany
| | - Dimitris Repantis
- Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin 12203 , Germany
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The past and future of novel, non-dopamine-2 receptor therapeutics for schizophrenia: A critical and comprehensive review. J Psychiatr Res 2019; 108:57-83. [PMID: 30055853 DOI: 10.1016/j.jpsychires.2018.07.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 06/13/2018] [Accepted: 07/12/2018] [Indexed: 01/28/2023]
Abstract
Since the discovery of chlorpromazine in the 1950's, antipsychotic drugs have been the cornerstone of treatment of schizophrenia, and all attenuate dopamine transmission at the dopamine-2 receptor. Drug development for schizophrenia since that time has led to improvements in side effects and tolerability, and limited improvements in efficacy, with the exception of clozapine. However, the reasons for clozapine's greater efficacy remain unclear, despite the great efforts and resources invested therewith. We performed a comprehensive review of the literature to determine the fate of previously tested, non-dopamine-2 receptor experimental treatments. Overall we included 250 studies in the review from the period 1970 to 2017 including treatments with glutamatergic, serotonergic, cholinergic, neuropeptidergic, hormone-based, dopaminergic, metabolic, vitamin/naturopathic, histaminergic, infection/inflammation-based, and miscellaneous mechanisms. Despite there being several promising targets, such as allosteric modulation of the NMDA and α7 nicotinic receptors, we cannot confidently state that any of the mechanistically novel experimental treatments covered in this review are definitely effective for the treatment of schizophrenia and ready for clinical use. We discuss potential reasons for the relative lack of progress in developing non-dopamine-2 receptor treatments for schizophrenia and provide recommendations for future efforts pursuing novel drug development for schizophrenia.
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12
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Room to move: Plasticity in early auditory information processing and auditory learning in schizophrenia revealed by acute pharmacological challenge. Schizophr Res 2018; 199:285-291. [PMID: 29627173 PMCID: PMC6151271 DOI: 10.1016/j.schres.2018.03.037] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/22/2018] [Accepted: 03/26/2018] [Indexed: 11/23/2022]
Abstract
Many patients with chronic psychotic disorders including schizophrenia (SZ) maintain meaningful levels of plasticity (i.e., capacity for change) within neurocognition-relevant brain mechanisms, as evidenced by gains in neurocognition and function after interventions such as targeted cognitive training. However, like many clinical features of these disorders, therapeutic responses in SZ are heterogeneous, and prospectively identifying treatment-sensitive individuals and individualized treatment modalities remains an unmet challenge. We propose that available plasticity in neurocognition-relevant brain mechanisms in individual SZ patients can be detected by gains in laboratory measures of early auditory information processing (EAIP) and auditory learning after a single challenge-dose of a pharmacologic agent; here, we present supportive data for this strategy with the non-competitive NMDA antagonist, memantine, and the psychostimulant, amphetamine. We describe a novel therapeutic model where this "challenge dose" strategy is used to prospectively identify a sensitive cohort of patients, and in these patients, a therapeutic response is elicited by pairing drug-enhanced EAIP and auditory learning with auditory-based targeted cognitive training.
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Swerdlow NR, Bhakta SG, Talledo JA, Franz DM, Hughes EL, Rana BK, Light GA. Effects of Amphetamine on Sensorimotor Gating and Neurocognition in Antipsychotic-Medicated Schizophrenia Patients. Neuropsychopharmacology 2018; 43:708-717. [PMID: 29154367 PMCID: PMC5809803 DOI: 10.1038/npp.2017.285] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/18/2017] [Accepted: 11/08/2017] [Indexed: 01/01/2023]
Abstract
Prepulse inhibition (PPI) of startle is being explored both as an indicator of target engagement for, and a biomarker predicting the sensitivity to, procognitive effects of drugs. We now report the effects of the pro-attentional drug, d-amphetamine, on PPI and neurocognition in antipsychotic-medicated schizophrenia patients and healthy subjects (HS) who were also tested in a targeted cognitive training (TCT) module. 44 HS and 38 schizophrenia patients completed a double-blind, placebo-controlled crossover study of the effects of a single dose of amphetamine (10 mg po) on PPI and MATRICS Consensus Cognitive Battery (MCCB) performance; TCT results were previously reported from 60 of these subjects. Moderators predicting AMPH sensitivity were assessed, including the rs4680 single-nucleotide polymorphism for catechol-O-methyltransferase (COMT). After placebo, patients exhibited PPI deficits with 60 ms prepulse intervals; these deficits were 'rescued' by amphetamine. The magnitude of amphetamine-enhanced PPI was greater in patients than in HS (p<0.032), and was associated with positive symptoms (p<0.007), antipsychotic load (p<0.015), hedonic effects of AMPH (p<0.003), and with the presence of at least one methionine allele in rs4680 (p<0.008). No significant effects of amphetamine on MCCB performance were detected in either group, though pro-attentional effects of amphetamine in patients were associated with greater amphetamine-enhanced TCT learning. Amphetamine acutely 'normalized' PPI in antipsychotic-medicated schizophrenia patients; no concurrent acute neurocognitive changes were detected by the MCCB. Findings suggest that in the context of appropriate antipsychotic medication, a low dose of amphetamine enhances brain processes associated with higher function in schizophrenia patients, without accompanying changes in MCCB performance.
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Affiliation(s)
- Neal R Swerdlow
- Department of Psychiatry, UCSD School of Medicine, La Jolla, CA, USA,Department of Psychiatry, UCSD School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0804, USA, Tel: +619-543-6270, Fax: +619-543-2493, E-mail:
| | - Savita G Bhakta
- Department of Psychiatry, UCSD School of Medicine, La Jolla, CA, USA
| | - Jo A Talledo
- Department of Psychiatry, UCSD School of Medicine, La Jolla, CA, USA
| | - Daniel M Franz
- Department of Psychiatry, UCSD School of Medicine, La Jolla, CA, USA
| | - Erica L Hughes
- Department of Psychiatry, UCSD School of Medicine, La Jolla, CA, USA
| | - Brinda K Rana
- Department of Psychiatry, UCSD School of Medicine, La Jolla, CA, USA
| | - Gregory A Light
- Department of Psychiatry, UCSD School of Medicine, La Jolla, CA, USA
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Bhakta SG, Light GA, Talledo JA, Balvaneda B, Hughes E, Alvarez A, Rana BK, Young JW, Swerdlow NR. Tolcapone-Enhanced Neurocognition in Healthy Adults: Neural Basis and Predictors. Int J Neuropsychopharmacol 2017; 20:979-987. [PMID: 29020372 PMCID: PMC5716101 DOI: 10.1093/ijnp/pyx074] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 08/10/2017] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Failure of procognitive drug trials in schizophrenia may reflect the clinical heterogeneity of schizophrenia, underscoring the need to identify biomarkers of treatment sensitivity. We used an experimental medicine design to test the procognitive effects of a putative procognitive agent, tolcapone, using an electroencephalogram-based cognitive control task in healthy subjects. METHODS Healthy men and women (n=27; ages 18-35 years), homozygous for either the Met/Met or Val/Val rs4680 genotype, received placebo and tolcapone 200 mg orally across 2 test days separated by 1 week in a double-blind, randomized, counterbalanced, within-subject design. On each test day, neurocognitive performance was assessed using the MATRICS Consensus Cognitive Battery and an electroencephalogram-based 5 Choice-Continuous Performance Test. RESULTS Tolcapone enhanced visual learning in low-baseline MATRICS Consensus Cognitive Battery performers (d=0.35) and had an opposite effect in high performers (d=0.5), and enhanced verbal fluency across all subjects (P=.03) but had no effect on overall MATRICS Consensus Cognitive Battery performance. Tolcapone reduced false alarm rate (d=0.8) and enhanced frontal P200 amplitude during correctly identified nontarget trials (d=0.6) in low-baseline 5 Choice-Continuous Performance Test performers and had opposite effects in high performers (d=0.5 and d=0.25, respectively). Tolcapone's effect on frontal P200 amplitude and false alarm rate was correlated (rs=-0.4, P=.05). All neurocognitive effects of tolcapone were independent of rs4680 genotype. CONCLUSION Tolcapone enhanced neurocognition and engaged electroencephalogram measures relevant to cognitive processes in specific subgroups of healthy individuals. These findings support an experimental medicine model for identifying procognitive treatments and provide a strong basis for future biomarker-informed procognitive studies in schizophrenia patients.
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Affiliation(s)
- Savita G Bhakta
- Department of Psychiatry, University of California, San Diego, La Jolla, California (Drs Bhakta and Light, Ms Talledo, Mr Balvaneda, Ms Hughes, Ms Alvarez, and Drs Rana, Young, and Swerdlow); Research Service MIRECC, VISN 22, Veterans Affairs San Diego Healthcare System, San Diego, California (Drs Light and Young),Correspondence: Savita G. Bhakta, MD, Assistant Professor, Department of Psychiatry, UCSD School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0804 ()
| | - Gregory A Light
- Department of Psychiatry, University of California, San Diego, La Jolla, California (Drs Bhakta and Light, Ms Talledo, Mr Balvaneda, Ms Hughes, Ms Alvarez, and Drs Rana, Young, and Swerdlow); Research Service MIRECC, VISN 22, Veterans Affairs San Diego Healthcare System, San Diego, California (Drs Light and Young)
| | - Jo A Talledo
- Department of Psychiatry, University of California, San Diego, La Jolla, California (Drs Bhakta and Light, Ms Talledo, Mr Balvaneda, Ms Hughes, Ms Alvarez, and Drs Rana, Young, and Swerdlow); Research Service MIRECC, VISN 22, Veterans Affairs San Diego Healthcare System, San Diego, California (Drs Light and Young)
| | - Bryan Balvaneda
- Department of Psychiatry, University of California, San Diego, La Jolla, California (Drs Bhakta and Light, Ms Talledo, Mr Balvaneda, Ms Hughes, Ms Alvarez, and Drs Rana, Young, and Swerdlow); Research Service MIRECC, VISN 22, Veterans Affairs San Diego Healthcare System, San Diego, California (Drs Light and Young)
| | - Erica Hughes
- Department of Psychiatry, University of California, San Diego, La Jolla, California (Drs Bhakta and Light, Ms Talledo, Mr Balvaneda, Ms Hughes, Ms Alvarez, and Drs Rana, Young, and Swerdlow); Research Service MIRECC, VISN 22, Veterans Affairs San Diego Healthcare System, San Diego, California (Drs Light and Young)
| | - Alexis Alvarez
- Department of Psychiatry, University of California, San Diego, La Jolla, California (Drs Bhakta and Light, Ms Talledo, Mr Balvaneda, Ms Hughes, Ms Alvarez, and Drs Rana, Young, and Swerdlow); Research Service MIRECC, VISN 22, Veterans Affairs San Diego Healthcare System, San Diego, California (Drs Light and Young)
| | - Brinda K Rana
- Department of Psychiatry, University of California, San Diego, La Jolla, California (Drs Bhakta and Light, Ms Talledo, Mr Balvaneda, Ms Hughes, Ms Alvarez, and Drs Rana, Young, and Swerdlow); Research Service MIRECC, VISN 22, Veterans Affairs San Diego Healthcare System, San Diego, California (Drs Light and Young)
| | - Jared W Young
- Department of Psychiatry, University of California, San Diego, La Jolla, California (Drs Bhakta and Light, Ms Talledo, Mr Balvaneda, Ms Hughes, Ms Alvarez, and Drs Rana, Young, and Swerdlow); Research Service MIRECC, VISN 22, Veterans Affairs San Diego Healthcare System, San Diego, California (Drs Light and Young)
| | - Neal R Swerdlow
- Department of Psychiatry, University of California, San Diego, La Jolla, California (Drs Bhakta and Light, Ms Talledo, Mr Balvaneda, Ms Hughes, Ms Alvarez, and Drs Rana, Young, and Swerdlow); Research Service MIRECC, VISN 22, Veterans Affairs San Diego Healthcare System, San Diego, California (Drs Light and Young)
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Swerdlow NR, Tarasenko M, Bhakta SG, Talledo J, Alvarez AI, Hughes EL, Rana B, Vinogradov S, Light GA. Amphetamine Enhances Gains in Auditory Discrimination Training in Adult Schizophrenia Patients. Schizophr Bull 2017; 43:872-880. [PMID: 27798224 PMCID: PMC5472129 DOI: 10.1093/schbul/sbw148] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Targeted cognitive training (TCT) of auditory processing enhances higher-order cognition in schizophrenia patients. TCT performance gains can be detected after 1 training session. As a prelude to a potential clinical trial, we assessed a pharmacological augmentation of cognitive therapy (PACT) strategy by testing if the psychostimulant, amphetamine, augments TCT gains in auditory processing speed (APS) in schizophrenia patients and healthy subjects (HS). HS and schizophrenia patients were tested in a screening session (test 1), followed by a double-blind crossover design (tests 2-3), comparing placebo vs amphetamine (10 mg; 7 d between tests). On each test day, 1 hour of Posit Science "Sound Sweeps" training was bracketed by 2- to 4-minute pre- and post-training assessments of APS. Training consisted of a speeded auditory time-order judgment task of successive frequency modulation sweeps. Auditory system "learning" (APS post- vs pre-training) was enhanced by amphetamine (main effect of drug: P < .002; patients: d = 0.56, P < .02; HS: d = 0.39, nonsignificant), and this learning was sustained for at least 1 week. Exploratory analyses assessed potential biomarker predictors of sensitivity to these effects of amphetamine. Amphetamine enhances auditory discrimination learning in schizophrenia patients. We do not know whether gains in APS observed in patients after 1 hour of TCT predict clinical benefits after a full course of TCT. If amphetamine can enhance the therapeutic effects of TCT, this would provide strong support for a "PACT" treatment paradigm for schizophrenia.
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Affiliation(s)
- Neal R. Swerdlow
- Department of Psychiatry, University of California, San Diego, La Jolla, CA
| | - Melissa Tarasenko
- Department of Psychiatry, University of California, San Diego, La Jolla, CA;,VISN-22 Mental Illness Research, Education, and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA
| | - Savita G. Bhakta
- Department of Psychiatry, University of California, San Diego, La Jolla, CA
| | - Jo Talledo
- Department of Psychiatry, University of California, San Diego, La Jolla, CA
| | - Alexis I. Alvarez
- Department of Psychiatry, University of California, San Diego, La Jolla, CA
| | - Erica L. Hughes
- Department of Psychiatry, University of California, San Diego, La Jolla, CA
| | - Brinda Rana
- Department of Psychiatry, University of California, San Diego, La Jolla, CA
| | | | - Gregory A. Light
- Department of Psychiatry, University of California, San Diego, La Jolla, CA;,VISN-22 Mental Illness Research, Education, and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA
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16
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Bhakta SG, Chou HH, Rana B, Talledo JA, Balvaneda B, Gaddis L, Light GA, Swerdlow NR. Effects of acute memantine administration on MATRICS Consensus Cognitive Battery performance in psychosis: Testing an experimental medicine strategy. Psychopharmacology (Berl) 2016; 233:2399-410. [PMID: 27076209 PMCID: PMC5214934 DOI: 10.1007/s00213-016-4291-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 04/01/2016] [Indexed: 02/06/2023]
Abstract
RATIONALE Pro-cognitive agents for chronic psychotic disorders (CPDs) might be detected via experimental medicine models, in which neural targets engaged by the drug predict sensitivity to the drug's pro-cognitive effects. OBJECTIVE This study aims to use an experimental medicine model to test the hypothesis that "target engagement" predicts pro-cognitive effects of the NMDA antagonist, memantine (MEM), in CPDs. METHODS MATRICS Consensus Cognitive Battery (MCCB) performance was assessed in CPD (n = 41) and healthy subjects (HS; n = 41) in a double-blind, randomized cross-over design of acute (single dose) MEM (placebo vs. 10 or 20 mg p.o.). Measures of prepulse inhibition (PPI) and mismatch negativity previously reported from this cohort substantiated target engagement. Biomarkers predicting MEM neurocognitive sensitivity were assessed. RESULTS Testing confirmed MCCB deficits associated with CPD diagnosis, age, and anticholinergic exposure. MEM (20 mg p.o.) reduced MCCB performance in HS. To control for significant test order effects, an "order-corrected MEM effect" (OCME) was calculated. In CPD subjects, greater age, positive MEM effects on PPI, and SNP rs1337697 (within the ionotropic NMDA receptor gene, GRIN3A) predicted greater positive OCME with 20 mg MEM. CONCLUSIONS An experimental medicine model to assess acute pro-cognitive drug effects in CPD subjects is feasible but not without challenges. A single MEM 20 mg dose had a negative impact on neurocognition among HS. In CPD patients, age, MEM effects on PPI, and rs1337697 predicted sensitivity to the neurocognitive effects of MEM. Any potential clinical utility of these predictive markers for pro-cognitive effects of MEM in subgroups of CPD patients cannot be inferred without a validating clinical trial.
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Affiliation(s)
- Savita G Bhakta
- Department of Psychiatry, UC San Diego School of Medicine, 9500 Gilman Dr., MC 0804, La Jolla, CA, 92093-0804, USA
| | - Hsun-Hua Chou
- Department of Psychiatry, UC San Diego School of Medicine, 9500 Gilman Dr., MC 0804, La Jolla, CA, 92093-0804, USA
| | - Brinda Rana
- Department of Psychiatry, UC San Diego School of Medicine, 9500 Gilman Dr., MC 0804, La Jolla, CA, 92093-0804, USA
| | - Jo A Talledo
- Department of Psychiatry, UC San Diego School of Medicine, 9500 Gilman Dr., MC 0804, La Jolla, CA, 92093-0804, USA
| | - Bryan Balvaneda
- Department of Psychiatry, UC San Diego School of Medicine, 9500 Gilman Dr., MC 0804, La Jolla, CA, 92093-0804, USA
| | - Laura Gaddis
- Department of Psychiatry, UC San Diego School of Medicine, 9500 Gilman Dr., MC 0804, La Jolla, CA, 92093-0804, USA
| | - Gregory A Light
- Department of Psychiatry, UC San Diego School of Medicine, 9500 Gilman Dr., MC 0804, La Jolla, CA, 92093-0804, USA
| | - Neal R Swerdlow
- Department of Psychiatry, UC San Diego School of Medicine, 9500 Gilman Dr., MC 0804, La Jolla, CA, 92093-0804, USA.
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Geerts H, Dacks PA, Devanarayan V, Haas M, Khachaturian ZS, Gordon MF, Maudsley S, Romero K, Stephenson D. Big data to smart data in Alzheimer's disease: The brain health modeling initiative to foster actionable knowledge. Alzheimers Dement 2016; 12:1014-1021. [PMID: 27238630 DOI: 10.1016/j.jalz.2016.04.008] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 03/25/2016] [Accepted: 04/26/2016] [Indexed: 02/07/2023]
Abstract
Massive investment and technological advances in the collection of extensive and longitudinal information on thousands of Alzheimer patients results in large amounts of data. These "big-data" databases can potentially advance CNS research and drug development. However, although necessary, they are not sufficient, and we posit that they must be matched with analytical methods that go beyond retrospective data-driven associations with various clinical phenotypes. Although these empirically derived associations can generate novel and useful hypotheses, they need to be organically integrated in a quantitative understanding of the pathology that can be actionable for drug discovery and development. We argue that mechanism-based modeling and simulation approaches, where existing domain knowledge is formally integrated using complexity science and quantitative systems pharmacology can be combined with data-driven analytics to generate predictive actionable knowledge for drug discovery programs, target validation, and optimization of clinical development.
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Affiliation(s)
- Hugo Geerts
- In Silico Biosciences, Inc., Berwyn, PA, USA.
| | - Penny A Dacks
- Alzheimer's Drug Discovery Foundation, New York, NY, USA
| | | | | | | | | | - Stuart Maudsley
- VIB Department of Molecular Genetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
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18
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Swerdlow NR, Light GA. Animal Models of Deficient Sensorimotor Gating in Schizophrenia: Are They Still Relevant? Curr Top Behav Neurosci 2015; 28:305-25. [PMID: 27311762 DOI: 10.1007/7854_2015_5012] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Animal models of impaired sensorimotor gating, as assessed by prepulse inhibition (PPI) of startle, have demonstrated clear validity at face, predictive, and construct levels for schizophrenia therapeutics, neurophysiological endophenotypes, and potential causative insults for this group of disorders. However, with the growing recognition of the heterogeneity of the schizophrenias, and the less sanguine view of the clinical value of antipsychotic (AP) medications, our field must look beyond "validity," to assess the actual utility of these models. At a substantial cost in terms of research support and intellectual capital, what has come from these models, that we can say has actually helped schizophrenia patients? Such introspection is timely, as we are reassessing not only our view of the genetic and pathophysiological diversity of these disorders, but also the predominant strategies for SZ therapeutics; indeed, our field is gaining awareness that we must move away from a "find what's broke and fix it" approach, toward identifying spared neural and cognitive function in SZ patients, and matching these residual neural assets with learning-based therapies. Perhaps, construct-valid models that identify evidence of "spared function" in neural substrates might reveal opportunities for future therapeutics and allow us to study these substrates at a mechanistic level to maximize opportunities for neuroplasticity. Such an effort will require a retooling of our models, and more importantly, a re-evaluation of their utility. For animal models to remain relevant in the search for schizophrenia therapeutics, they will need to focus less on what is valid and focus more on what is useful.
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Affiliation(s)
- Neal R Swerdlow
- Department of Psychiatry, School of Medicine, University of California, San Diego, 9500 Gilman Dr. La Jolla, San Diego, CA, 92093-0804, USA.
| | - Gregory A Light
- Department of Psychiatry, School of Medicine, University of California, San Diego, 9500 Gilman Dr. La Jolla, San Diego, CA, 92093-0804, USA
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19
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Light GA, Swerdlow NR. Neurophysiological biomarkers informing the clinical neuroscience of schizophrenia: mismatch negativity and prepulse inhibition of startle. Curr Top Behav Neurosci 2014; 21:293-314. [PMID: 24850080 PMCID: PMC5951188 DOI: 10.1007/7854_2014_316] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
With the growing recognition of the heterogeneity of major brain disorders, and particularly the schizophrenias (SZ), biomarkers are being sought that parse patient groups in ways that can be used to predict treatment response, prognosis, and pathophysiology. A primary focus to date has been to identify biomarkers that predict damage or dysfunction within brain systems in SZ patients, that could then serve as targets for interventions designed to "undo" the causative pathology. After almost 50 years as the predominant strategy for developing SZ therapeutics, evidence supporting the value of this "find what's broke and fix it" approach is lacking. Here, we suggest an alternative strategy of using biomarkers to identify evidence of spared neural and cognitive function in SZ patients, and matching these residual neural assets with therapies toward which they can be applied. We describe ways to extract and interpret evidence of "spared function," using neurocognitive, and neurophysiological measures, and, suggest that further evidence of available neuroplasticity might be gleaned from studies in which the response to drug challenges and "practice effects" are measured. Finally, we discuss examples in which "better" (more normal) performance in specific neurophysiological measures predict a positive response to a neurocognitive task or therapeutic intervention. We believe that our field stands to gain tremendous therapeutic leverage by focusing less on what is "wrong" with our patients, and instead, focusing more on what is "right".
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Affiliation(s)
- Gregory A Light
- Department of Psychiatry, School of Medicine, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA, 92093-0804, USA
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Gilleen J, Michalopoulou PG, Reichenberg A, Drake R, Wykes T, Lewis SW, Kapur S. Modafinil combined with cognitive training is associated with improved learning in healthy volunteers--a randomised controlled trial. Eur Neuropsychopharmacol 2014; 24:529-39. [PMID: 24485800 DOI: 10.1016/j.euroneuro.2014.01.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 01/06/2014] [Accepted: 01/07/2014] [Indexed: 10/25/2022]
Abstract
Improving cognition in people with neuropsychiatric disorders remains a major clinical target. By themselves pharmacological and non-pharmacological approaches have shown only modest effects in improving cognition. In the present study we tested a recently-proposed methodology to combine CT with a 'cognitive-enhancing' drug to improve cognitive test scores and expanded on previous approaches by delivering combination drug and CT, over a long intervention of repeated sessions, and used multiple tasks to reveal the cognitive processes being enhanced. We also aimed to determine whether gains from this combination approach generalised to untrained tests. In this proof of principle randomised-controlled trial thirty-three healthy volunteers were randomised to receive either modafinil or placebo combined with daily cognitive training over two weeks. Volunteers were trained on tasks of new-language learning, working memory and verbal learning following 200 mg modafinil or placebo for ten days. Improvements in trained and untrained tasks were measured. Rate of new-language learning was significantly enhanced with modafinil, and effects were greatest over the first five sessions. Modafinil improved within-day learning rather than between-day retention. No enhancement of gains with modafinil was observed in working memory nor rate of verbal learning. Gains in all tasks were retained post drug-administration, but transfer effects to broad cognitive abilities were not seen. This study shows that combining CT with modafinil specifically elevates learning over early training sessions compared to CT with placebo and provides a proof of principle experimental paradigm for pharmacological enhancement of cognitive remediation.
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Affiliation(s)
- J Gilleen
- Institute of Psychiatry, King's College, London SE5 8AF, United Kingdom.
| | - P G Michalopoulou
- Institute of Psychiatry, King's College, London SE5 8AF, United Kingdom
| | - A Reichenberg
- Institute of Psychiatry, King's College, London SE5 8AF, United Kingdom
| | - R Drake
- Institute of Brain, Behaviour and Mental Health, University of Manchester, United Kingdom
| | - T Wykes
- Institute of Psychiatry, King's College, London SE5 8AF, United Kingdom
| | - S W Lewis
- Institute of Brain, Behaviour and Mental Health, University of Manchester, United Kingdom
| | - S Kapur
- Institute of Psychiatry, King's College, London SE5 8AF, United Kingdom
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