[Review: executive functioning and cannabis use].
OBJECTIVE
Cannabis is the most used illicit drug worldwide, however only a few studies have examined cognitive deficits related to its use. Clinical manifestations associated with those deficits include a motivational syndrome, impairment in cognitive flexibility, inattention, deficits in abstract reasoning and concept formation, aspects intimately related to the executive functions, which potentially exert a central role in substance dependence. The objective was to make a review about consequences of cannabis use in executive functioning.


METHODS
This review was carried out on reports drawn from MedLine, SciELO, and Lilacs.


CONCLUSIONS
In studies investigating acute use effects, higher doses of tetrahydrocannabinol are associated to impairments in performance of nonsevere users in planning and control impulse tasks. However, chronic cannabis users do not show those impairments. Although demonstration of residual effects of cannabis in the executive functioning is controversial, persistent deficits seem to be present at least in a subgroup of chronic users after 28 days of abstinence.


CONCLUSIONS
The neuropsychological studies found did not have as a main aim the evaluation of executive functioning. A criterial selection of standardized neuropsychological tests, more appropriate study designs as well as concomitant investigations with structural and functional neuroimaging techniques may improve the understanding of eventual neurotoxicity associated with cannabis use.
Almeida
Priscila Previato
PP
Laboratório Interdisciplinar de Neurociências Clínicas, Departamento de Psiquiatria, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brasil. priscilapreviato@yahoo.co.br
Novaes
Maria Alice Fontes Pinto
MA
Bressan
Rodrigo Affonseca
RA
Lacerda
Acioly Luiz Tavares de
AL
D001288:Attention / Q000187:drug effects; D002186:Cannabinoids / Q000494:pharmacology*; D003071:Cognition / Q000187:drug effects*; D003072:Cognition Disorders / Q000139:chemically induced* / Q000503:physiopathology; D003210:Concept Formation / Q000187:drug effects; D003657:Decision Making; D013759:Dronabinol / Q000633:toxicity; D005625:Frontal Lobe / Q000187:drug effects; D006801:Humans; D007175:Impulsive Behavior / Q000139:chemically induced / Q000503:physiopathology / Q000523:psychology; D002189:Marijuana Abuse / Q000523:psychology*; D008385:Marijuana Smoking / Q000009:adverse effects* / Q000503:physiopathology / Q000523:psychology; D009483:Neuropsychological Tests
D002186:Cannabinoids; D013759:Dronabinol