Comorbidity of Schizophrenia and Substance Abuse
Henry A. Nasrallah, MD, Saint Louis University
Approximately one-half of patients with schizophrenia have comorbid substance abuse, including nicotine, alcohol, Cannabis, and other substances, a rate that is approximately 3 times higher than in the general population. Drugs of abuse that directly increase dopamine transmission in the nucleus accumbens produce a “high” as well as psychotic symptoms. Clozapine, although usually used only for refractory patients, might be helpful in reducing substance abuse; case reports include alcohol, cocaine, nicotine, and polydrug use. Risperidone may be helpful, but only 12% of drug abusing patients taking risperidone achieved abstinence compared with 54% with clozapine. Naltrexone has evidence of efficacy for alcohol abuse. Evidence is mixed or insufficient for olanzapine, ziprasidone, aripiprazole, and anticonvulsants.
