Vilazodone for cannabis dependence: A randomized, controlled pilot trial

The purpose of this study was to evaluate the efficacy of vilazodone, a selective serotonin receptor inhibitor and partial 5-HT1A agonist, for treatment of cannabis dependence.

Seventy-six cannabis-dependent adults were randomized to receive either up to 40 mg/day of vilazodone (n = 41) or placebo (n = 35) for 8 weeks combined with a brief motivational enhancement therapy intervention and contingency management to encourage study retention. Cannabis use outcomes were assessed via weekly urine cannabinoid tests; secondary outcomes included cannabis use self-report and cannabis craving.

Participants in both groups reported reduced self-reported cannabis use over the course of the study; however, vilazodone provided no advantage over placebo in reducing cannabis use. Men had significantly lower creatinine-adjusted cannabinoid levels and a trend for increased negative urine cannabinoid tests than women.

Vilazodone was not more efficacious than placebo in reducing cannabis use. Important gender differences were noted, with women having worse cannabis use outcomes than men.

Further medication development efforts for cannabis use disorders are needed, and gender should be considered as an important variable in future trials.