Concurrent Abuse of Cannabis Is Associated with a Shorter Duration of Hospitalization in Treatment-Resistant Psychotic Bipolar Inpatients Treated with Clozapine

Abstract

Typical antipsychotic agents have shown little efficacy in the treatment of acute psychoses in patients whose clinical picture is characterized by concurrent substance abuse. Substance-related issues usually not only remain unimproved while being treated with atypical antipsychotics but very often show an increase in severity. The fact that they have no quick or global effectiveness on psychotic phenomena is especially troubling because abused substances oftentimes have the effect of reinforcing and maintaining psychotic symptoms. In this observational study, we compared the discharge rate in 30 cannabis-abusing patients and in 26 nonabusers, who were males, treatment-resistant psychotic bipolar in-patients, treated with clozapine. Discharge rates 30 days after the start of treatment were 23.1% for nonabusers and 53.3% for abuser patients (P=0.04). Discharge rates at 60 days were 80.8% for nonabusers and 83.3% for abuser patients. We submit the hypothesis that underactivity of the meso-limbic pathway by treatment with typical antipsychotics makes cannabis abuse more likely, and as such, treatment with Clozapine is more effective.