A pilot study of quetiapine in patients with bipolar disorder and cocaine dDependence

Bipolar disorder is associated with high rates of substance use disorders. However, few treatment trials are reported in this population. The goal of this pilot study was to obtain randomized, placebo-controlled data on quetiapine in bipolar disorder and cocaine dependence. Twelve outpatients with bipolar disorder and cocaine dependence were randomized to 12 weeks of quetiapine or placebo as add-on therapy. Participants were titrated within one week to 400 mg/day with flexible titration to a maximum of 800 mg/day. Cocaine and other substance use, craving, mood symptoms, and safety/tolerability were assessed. No significant between-group differences were observed in cocaine use or craving. The quetiapine group had significantly fewer heavy drinking days than the placebo group and showed a trend toward longer treatment retention. Significant between-group differences in mood measures were not observed, although differences in depression scores, favoring quetiapine, showed a large effect size. Other than constipation, which was more common with quetiapine, side effects did not show significant between-group differences. Quetiapine was not associated with reduction in cocaine use, but was associated with reduction in alcohol use and longer time in treatment and was generally well-tolerated. Larger trials of quetiapine in dual diagnosis patients seem warranted.