Pharmacology and effects of cannabis: a brief review.

BACKGROUND: Increasing prevalence of recreational cannabis use among the young population has stimulated debate on the possible effects of acute and longterm use.

AIMS: To highlight recent knowledge of mechanisms of action, effects on psychomotor and cognitive performance, and health risks associated with cannabis consumption.

METHOD: A brief review of recent literature on the prevalence of recreational cannabis use, the potency of modern cannabis preparations and the pharmacological actions of cannabis.

RESULTS: Cannabinoids derived from herbal cannabis interact with endogenous cannabinoid systems in the body. Actions on specific brain receptors cause dose-related impairments of psychomotor performance with implications for car and train driving, aeroplane piloting and academic performance. Other constituents of cannabis smoke carry respiratory and cardiovascular health risks similar to those of tobacco smoke.

CONCLUSIONS: Cannabis is not, as widely perceived, a harmless drug but poses risks to the individual and to society.