Reflection impulsivity in current and former substance users.
BACKGROUND
Chronic drug use is associated with increased impulsivity, risky decision making, and impaired behavioral control, but the underlying mechanisms of this neurocognitive profile remain unclear. We investigated impulsive responding in the context of decision making, using a novel behavioral measure of reflection impulsivity: the tendency to gather and evaluate information before making a decision.


METHODS
The Information Sampling Task was administered to current substance users dependent on amphetamines (n = 24) or opiates (n = 40), former users of amphetamines or opiates abstinent for at least 1 year (n = 24), and non-drug-using control subjects (n = 26).


RESULTS
Current users of amphetamines and opiates sampled less information than control subjects and responded at a lower probability of making a correct response. Amphetamine- and opiate-dependent subjects did not differ. Reduced reflection was also apparent in the former substance users, who did not differ from the current users. Questionnaire ratings of impulsivity (on the Barratt Impulsivity Scale, version 11) were also inflated in three groups of substance users but were not significantly correlated with performance on the behavioral task.


CONCLUSIONS
Reduced reflection is suggested to represent a cognitive marker for substance dependence that does not recover with prolonged abstinence and is associated with multiple drugs of abuse.
Clark
Luke
L
Department of Experimental Psychology, University of Cambridge, Cambridge, United Kingdom.
Robbins
Trevor W
TW
Ersche
Karen D
KD
Sahakian
Barbara J
BJ
D000328:Adult; D003071:Cognition / Q000502:physiology*; D003657:Decision Making; D005260:Female; D006801:Humans; D007175:Impulsive Behavior; D007600:Judgment; D008297:Male; D019966:Substance-Related Disorders / Q000503:physiopathology / Q000523:psychology*