Diazepam produces disinhibitory cognitive effects in male volunteers

• Published in: Psychopharmacologia Vol. 173; no. 1-2; pp. 88 - 97
• Main Authors: DEAKIN, J. B, AITKEN, M. R. F, DOWSON, J. H, ROBBINS, T. W, SAHAKIAN, B. J
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01-04-2004; Springer Nature B.V
• Subjects: Adult; Anti-Anxiety Agents - adverse effects; Anti-Anxiety Agents - pharmacology; Attention - drug effects; Biological and medical sciences; Cognition - drug effects; Decision Making - drug effects; Diazepam - adverse effects; Diazepam - pharmacology; Dose-Response Relationship, Drug; Double-Blind Method; Fundamental and applied biological sciences. Psychology; Humans; Male; Medical sciences; Memory - drug effects; Neuropharmacology; Neuropsychological Tests - statistics & numerical data; Pattern Recognition, Visual - drug effects; Pharmacology. Drug treatments; Problem Solving - drug effects; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychomotor Performance - drug effects; Reaction Time - drug effects; Human; Decision-making; Impulsivity; Gambling; Decision making; Response bias; Male; Cognition; Prefrontal cortex; Gambling game; Tranquillizer; Benzodiazepine derivatives; Inhibition; Diazepam
• ISSN: 0033-3158; 1432-2072
• DOI: 10.1007/s00213-003-1695-4

Diazepam has well known amnestic and sedative effects but effects on fronto-executive function remain largely uninvestigated, especially on neuropsychologically validated tests of risk taking and orbitofrontal cortex function.
We aimed to determine the impact of diazepam on a variety of executive tasks.
The effects of 5, 10 and 20 mg of diazepam on a battery of neuropsychological tests were investigated using a randomised, double blind, placebo-controlled design. Seventy-five adult men were recruited. The Rogers et al. (1999b) test of risk-taking was given along with tasks from the CANTAB battery.
Diazepam impaired performance on the Tower of London test of planning, without influencing visual pattern recognition memory. Subjects who had taken diazepam made more risky choices on the risk-taking task. On two speeded reaction time tasks diazepam impaired discrimination sensitivity and increased the bias to respond.
In contrast to the well-known sedative effects of diazepam, we demonstrate disinhibitory effects on two speeded reaction time tasks. Our results show that diazepam can impair performance on reaction time tasks both by impairing sensitivity and by increasing the bias to respond. Furthermore diazepam impaired performance on tests of planning and risky decision making that depend predominantly on dorsolateral and orbitofrontal regions of the prefrontal cortex, respectively.