The American Psychiatric Association (APA) has updated its Privacy Policy and Terms of Use, including with new information specifically addressed to individuals in the European Economic Area. As described in the Privacy Policy and Terms of Use, this website utilizes cookies, including for the purpose of offering an optimal online experience and services tailored to your preferences.

Please read the entire Privacy Policy and Terms of Use. By closing this message, browsing this website, continuing the navigation, or otherwise continuing to use the APA's websites, you confirm that you understand and accept the terms of the Privacy Policy and Terms of Use, including the utilization of cookies.

×

There are high rates of substance use in patients diagnosed with schizophrenia. The objective of this review is to update clinicians about the epidemiology, consequences, assessment and treatment of comorbid substance use disorders and schizophrenia. Alcohol, cannabis and cocaine are among the most frequently abused substances in patients with schizophrenia. Substance abuse can negatively affect the expression and course of schizophrenia, for example by leading to a lower global level of functioning, increased hospitalizations, increased service utilization, and lower compliance with medication. Several models have been proposed to explain the high rates of comorbid substance use disorder in patients with schizophrenia including the self-medication and reward dysfunction hypotheses. There is little evidence to support the self-medication hypothesis. The reward dysfunction hypothesis is gaining support. The high rates and negative consequences warrant a thorough assessment of comorbid substance use disorders when treating patients with schizophrenia. The existing treatments are not particularly effective. Combination pharmacotherapy and behavioral strategies may be superior to either alone in the treatment of schizophrenia with comorbid substance use disorders. Due to the changing nature of DSM definitions of substance abuse and the drugs which are being abused, clinicians must strive to stay up to date on the latest findings related to co-occurring disorders among people with schizophrenia.