Social functioning, psychopathology, and medication side effects in relation to substance use and abuse in schizophrenia.

OBJECTIVE: To identify correlates of self-reported substance use and problems associated with that use in people with schizophrenia.
METHODS: A sample of 404 patients with schizophrenia, schizoaffective disorder, or schizophreniform disorder and longitudinal assessments of substance use were examined. Three groups were formed according to consistency of substance use over time: No/Low Alcohol, Alcohol Only, and Drug Use (with or without alcohol use). Similar groups were formed regarding problems associated with alcohol use. Groups were compared on demographics, psychiatric history, psychopathology, medication side effects, and social functioning.
RESULTS: Substance users were more likely to be young, male, and to have lower levels of education. Substance users generally had fewer negative symptoms, more social contacts, and better social-leisure functioning. However, substance users, especially drug users, also were rated as having more interpersonal and family problems, had an earlier age at first psychiatric hospitalization, and were more likely to have been recently hospitalized. Patients reporting problems with alcohol use reported more frequent alcohol and drug use, greater severity of akathisia, and problems in interpersonal, family, and self-efficacy domains.
CONCLUSIONS: Many of the same variables that correlate with substance use disorder also correlated with moderate substance use in this sample of people with schizophrenia. Although moderate users of alcohol and drugs may have better social functioning in some areas, they also are likely to have substantial problems in interpersonal relationships, especially those involving family members.