Accuracy of the Depression, Anxiety and Stress Scale (DASS-21) for Screening on Comorbid Internalizing Disorders among Youth in Substance Use Disorder Treatment

Introduction: Major depression, anxiety disorders, and post-traumatic stress disorder (PTSD) are among the most prevalent comorbid mental disorders in youth addiction treatment. Hence, screening for these internalizing disorders should be part of the standard routine at intake in substance use disorder treatment. We investigated the usefulness of the Depression, Anxiety and Stress Scale (DASS-21) as a screener for this purpose. Methods: A nationally representative sample of 421 treatment-seeking youths aged 16-22 years with a primary cannabis, alcohol, cocaine, or amphetamine use disorder participated in the study. At intake, we administered the DASS-21 and the Mini International Neuropsychiatric Interview (MINI; Sheehan et al., 1998) based on the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5), as "gold standard,"as part of a broader baseline assessment of the Youth in transition study [Moska et al. BMC Psychiatry. 2021;21(1):1-11]. Results: At comparable sensitivity (0.80-0.84), based on the optimal cut-off value, specificity was higher for the DASS-21 total score detecting any DSM-5 internalizing disorder (0.62) than for the DASS subscales specifically detecting depression, anxiety, or PTSD (0.44, 0.49, and 0.51, respectively). Receiver operating characteristic curve analyses showed an area under the curve (AUC) value of 0.80 for the DASS total score to detect any internalizing disorder ("good discrimination"), compared with AUC values of 0.70-0.75 of the DASS depression and anxiety subscales to detect DSM-5 depression, anxiety, and PTSD ("fair discrimination"). The optimal DASS total score cut-off value of ≥44 for detecting any internalizing disorder resulted in 0.81 sensitivity, 0.62 specificity, 0.80 positive predictive value, and 0.64 negative predictive value. Conclusion: Given the high prevalence of comorbid internalizing disorders in youth addiction care, the need to address these comorbid disorders in treatment, and the favorable accuracy of the DASS to detect these disorders, we recommend to implement the DASS-21 as routine screener in youth addiction treatment in the Netherlands.