Medication noncompliance and substance abuse among patients with schizophrenia.

OBJECTIVE: The study examined the effect of medication noncompliance and substance abuse on symptoms of schizophrenia. METHODS: Short-term inpatients with a diagnosis of schizophrenia were enrolled in a longitudinal outcomes study and continued to receive standard care after discharge. At baseline and six-month follow-up, Brief Psychiatric Rating Scale (BPRS) scores and data on subjects' reported medication compliance, drug and alcohol abuse, usual living arrangements, and observed side effects were obtained. The number of outpatient contacts during the follow-up period was obtained from medical records. Relationships between the dependent variables-medication noncompliance and follow-up BPRS scores-and the independent variables were analyzed using logistic and linear regression models. RESULTS: Medication noncompliance was significantly associated with substance abuse. Subjects who abused substances, had no outpatient contact, and were noncompliant with medication had significantly greater symptom severity than other groups. CONCLUSIONS: Substance abuse is strongly associated with medication noncompliance among patients with schizophrenia. The combination of substance abuse, medication noncompliance, and lack of outpatient contact appears to define a particularly high-risk group.