Accuracy of self-report, biological tests, collateral reports and clinician ratings in identifying substance use disorders among adults with schizophrenia.

Identifying substance use disorders among adults with schizophrenia presents unique challenges but is critical to research and practice. This study examined: (a) the accuracy of assessments completed using various approaches in identifying substance use disorders, (b) their ability to discriminate between disorders of abuse and dependence, and (c) the benefits of using multiple indicators to identify substance use disorders. Data are from the Clinical Antipsychotic Trials of Intervention Effectiveness study. The sample comprised 1,460 community-based adults with schizophrenia, 15.8% (n = 230) of whom were positive for a current (past month) drug or alcohol use disorder using the Structured Clinical Interview for DSM-IV Disorders (SCID). Clinician ratings, self-report, collateral reports, and results of hair and urine tests were compared to SCID diagnoses. Congruence with SCID diagnoses was good across approaches and evidence for superiority of one approach over another was limited. No approach discriminated between abuse and dependence. There was limited benefit of using multiple indicators. Findings suggest that the decision regarding the "best" approach for identifying substance use disorders among adults with schizophrenia may be made through consideration of practical issues and assessment purpose, rather than selection of the approach that yields the most accurate diagnostic assessment.