Long-term heavy marijuana users make costly decisions on a gambling task.
BACKGROUND
Chronic marijuana use has been associated with impairments of learning, memory, and executive functions. Little is known, however, about the effects of marijuana use on other cognitive domains, such as decision-making, which are thought to play an important role in addiction and drug abuse.


OBJECTIVE
The purpose of the present study was to determine if long-term heavy marijuana users employ different decision-making strategies than individuals with minimal marijuana exposure.


METHODS
Volunteers were assigned to a cannabis (n = 10) or control group (n = 10) based upon history of prior marijuana use. Demographic and neuropsychological variables were evaluated, and a decision-making task--the gambling task (GT) was administered.


RESULTS
Although few demographic and neuropsychological differences were noted between groups, marijuana users made more decisions that led to larger immediate gains despite more costly losses than controls.


CONCLUSIONS
These data suggest that long-term heavy marijuana users may have specific deficits in the ability to balance rewards and punishments that may contribute to continued drug-taking behavior. It is unknown, however, whether the basis for such deficits might be attributed directly to marijuana exposure or pre-existing genetic or behavioral differences.
Whitlow
Christopher T
CT
Department of Physiology and Pharmacology, Center for the Neurobiological Investigation of Drug Abuse, Wake Forest University School of Medicine, Medical Center Boulevard, Winston Salem, NC 27157-1083, USA.
Liguori
Anthony
A
Livengood
L Brooke
LB
Hart
Stephanie L
SL
Mussat-Whitlow
Becky J
BJ
Lamborn
Corey M
CM
Laurienti
Paul J
PJ
Porrino
Linda J
LJ
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D003657:Decision Making; D005260:Female; D005715:Gambling / Q000523:psychology*; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000191:economics* / Q000523:psychology*; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D013995:Time