Validation of the Swedish version of the Reynolds Adolescent Depression Scale second edition (RADS-2) in a normative sample

Background: Due to the sharp global increase in prevalence of adolescent major depressive disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders, we need internationally validated tools for multi-dimensional assessment. Reynolds Adolescent Depression Scale second edition (RADS-2) measures dysphoric mood, anhedonia/negative affect, negative self-evaluation and somatic complaints and is widely used internationally, but not yet available in Swedish. Aim: The aim of this study is to test the psychometric characteristics of the Swedish version of RADS-2 in a normative sample. Material and method: Data was gathered from junior and high school students in Northern Sweden (N = 637). We performed: 1. Confirmatory factor analysis to examine the 4-factor structure proposed by Reynolds, 2. Measurement invariance analysis for sex (girls, boys) and age group (12-15 years, 16-20 years). 3. Reliability testing and 4. Tests for concurrent, discriminant and convergent validity using Beck's Youth Inventories of Emotional and Social Impairment Depression and Anger subscales, the Patient Reported Outcome Measurements Information System, Anxiety and Friends subscales and the World Health Organization Wellness Index. Results: The sample consisted of n = 637 students (n = 389 girls and n = 248 boys), mean age 15.73 (SD = 1.76); 12-20 years. The 4-factor structure was confirmed, as well as measurement invariance for sex and age group. Reliability was acceptable to excellent for all subscales and RADS-2 total scale. Concurrent, convergent and discriminant validity was good. Conclusion: The Swedish version of RADS-2 showed acceptable reliability and validity in a Swedish normative sample