Objective: Although a growing body of research suggests that atypical neuroleptic medications are efficacious in the treatment of cocaine addiction among individuals with schizophrenia, more rigorously controlled trials are needed. To extend this research, we performed a 6-week double-blind study comparing olanzapine to haloperidol with the primary objective of reducing cue-elicited cocaine craving and the secondary aims of decreasing substance use, improving psychiatric symptoms, and determining an effect size for future studies.

Methods: Thirty-one subjects with cocaine dependence and schizophrenia were randomized to olanzapine or haloperidol, underwent a cue-exposure procedure, and completed psychiatric and substance abuse ratings.

Results: Individuals in the olanzapine group who completed the study had a significant reduction on the energy subscale of the Voris Cocaine Craving Scale at study completion compared with individuals in the haloperidol group. The olanzapine-treated group also had lower, but not statistically significant, PANSS General Psychopathology Subscale scores and fewer positive urine toxicology screens compared with those in the haloperidol group.

Conclusion: This small, but rigorously controlled, pilot trial provides additional evidence for the use of atypical antipsychotics for the treatment of individuals with co-occurring schizophrenia and cocaine dependence. Reductions in craving were associated with medium to large effect sizes.