Screening for psychiatric disorders in outpatients with DSM-IV substance use disorders

Psychiatric disorders are frequent in patients with substance use disorders, and have been associated with increased morbidity and poorer treatment outcome. Because of the clinical importance of comorbid mental disorders, concerns have been raised about the detection of psychiatric disorders in patients with substance use disorders. The Psychiatric Diagnostic Screening Questionnaire (PDSQ) is a brief, psychometrically strong, self-report scale designed to screen for the most common DSM-IV Axis I disorders encountered in outpatient mental health settings. Previously we described the diagnostic performance of the PDSQ in a large sample of psychiatric outpatients. For the present report, we examined the performance of the PDSQ in psychiatric outpatients with drug and alcohol abuse and dependence, and determined whether its performance in patients with substance use disorders is as good as it is in patients without substance use disorders. For the patients with a substance use disorder, 92% of the comorbid mental disorders were detected by the PDSQ subscales (i.e., mean sensitivity across subscales equals 92%) and 97% of the patients who screened negative did not have a disorder (i.e., mean negative predictive value equals 97%). For patients without a substance use disorder, the mean sensitivity and negative predictive values were 88% and 95%, respectively. Receiver Operating Characteristic curves were plotted for each PDSQ subscale for both patient groups, and all areas under the curve were significant and similar in the two groups.