Validation of Addiction Severity Index (ASI) for Assessment of Psychiatric Comorbidity in Multi-Site Randomized Controlled Trials

Objective: This study aimed to assess the validity of the psychiatric problems subscale of the Addiction Severity Index (ASI-psych) to ascertain psychiatric comorbidity among individuals participating in randomized controlled trials (RCTs) of substance use disorder (SUD) treatments. Methods: The ASI-psych score among 1,660 RCT participants of National Institute of Drug Abuse Clinical Trials Network studies was compared against diagnosis of any serious mental disorder based on the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (SCID) or Mini-International Neuropsychiatric Interview (MINI). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) for detecting any serious mental disorders were estimated by the receiver operating characteristic (ROC) analysis. Results: Based on the overall sample, the AUC score for any serious mental disorder was 0.72 (95% confidence interval [CI], [0.69, 0.75]) with the optimal ASI-psych score of 24.6. There was no statistically significant difference in AUCs based on the SCID and MINI (chi(2) = 0.05, p = .82) or by target drugs of RCTs (chi(2) =1.33, p = .72). Conclusions: Results support the utility of the ASI in screening for psychiatric comorbidity among patients receiving SUD treatments in RCT settings.