[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address 54.163.129.96. Please contact the publisher to request reinstatement.
[Skip to Content Landing]
Article
November 1996

Cognitive Correlates of Long-term Cannabis Use in Costa Rican Men

Author Affiliations

From the Departments of Pediatrics (Dr Fletcher) and Psychiatry and Behavioral Sciences (Drs Fletcher and Davis), University of Texas-Houston Medical School; Department of Psychiatry, University of Miami (Fla) School of Medicine (Dr Page); Department of Psychology, University of Houston (Drs Francis and Naus and Ms Copeland); Department of Psychology, Georgia State University, Atlanta (Dr Morris); Department of Psychology, University of Costa Rica, San José (Dr Krauskopf); and the Neuropsychiatrie Institute, University of California, Los Angeles (Dr Satz).

Arch Gen Psychiatry. 1996;53(11):1051-1057. doi:10.1001/archpsyc.1996.01830110089011
Abstract

Background:  Cognitive correlates of long-term cannabis use have been elusive. We tested the hypothesis that long-term cannabis use is associated with deficits in shortterm memory, working memory, and attention in a literate, westernized culture (Costa Rica) in which the effects of cannabis use can be isolated.

Methods:  Two cohorts of long-term cannabis users and nonusers were studied. Within each cohort, users and nonusers were comparable in age and socioeconomic status. Polydrug users and users who tested positive for the use of cannabis at the time of cognitive assessment after a 72-hour abstention period were excluded. The older cohort (whose age was ~45 years) had consumed cannabis for an average of 34 years, and comprised 17 users and 30 nonusers, who had been recruited in San José, Costa Rica, and had been observed since 1973. The younger cohort (whose age was ~28 years) had consumed cannabis for an average of 8 years, and comprised 37 users and 49 nonusers. Short-term memory, working memory, and attentional skills were measured in each subject.

Results:  Older long-term users performed worse than older nonusers on 2 short-term memory tests involving learning lists of words. In addition, older long-term users performed worse than older nonusers on selective and divided attention tasks associated with working memory. No notable differences were apparent between younger users and nonusers.

Conclusion:  Long-term cannabis use was associated with disruption of short-term memory, working memory, and attentional skills in older long-term cannabis users.

×