Acute Effects of Smoked and Vaporized Cannabis in Healthy Adults Who Infrequently Use Cannabis

Key Points Question How does smoked and vaporized cannabis acutely influence subjective drug effects, cognitive and psychomotor performance, and cardiovascular measures in healthy adults who infrequently use cannabis (>30 days since last use)? Findings In a crossover trial of 17 healthy adults, inhalation of smoked and vaporized cannabis containing 10 mg of Δ9-tetrahydrocannabinol (THC) produced discriminative drug effects and modest impairment of cognitive functioning, while inhalation of a 25-mg dose of THC was associated with pronounced drug effects, increased incidence of adverse effects, and significant impairment of cognitive and psychomotor ability. Vaporized cannabis produced greater pharmacodynamic effects and higher concentrations of THC in blood compared with equal doses of smoked cannabis. Meaning Significant, sometimes adverse, drug effects can occur at relatively low THC doses in infrequent cannabis users, and accordingly these data should be considered with regard to regulation of retail cannabis products and education for individuals initiating cannabis use.