Psychological Assessment, Vol 37(9), Sep 2025, 401-414; doi:10.1037/pas0001389
The Inventory of Depression and Anxiety Symptoms–II (IDAS-II) addresses current clinical demands by providing individual scores for depressive, anxiety, and bipolar symptoms consistent with transdiagnostic approaches and the Hierarchical Taxonomy of Psychopathology. The general aim was to expand the clinical utility of the IDAS-II to assess changes in internalizing symptoms, quality of life (QoL), and disability. Participants included 1,072 community adults (50% women) and 289 patients (74% women) who completed the IDAS-II. Patients also completed the Short Form–36 Health Survey and World Health Organization Disability Assessment Schedule to evaluate QoL and disability, respectively. First, the sensitivity of the IDAS-II scores to treatment impact was assessed through statistical significance and reliable changes based on the internal consistency of the IDAS-II. Second, the relationship between changes in IDAS-II scores and changes in QoL and disability was analyzed using weighted Cohen’s κ and Spearman correlations. Third, an anchor-based longitudinal method determined the minimal clinically important difference in QoL and disability for the IDAS-II scales (i.e., the smallest difference in IDAS-II scores perceived as beneficial for QoL and disability). Reliable change index values and cutoff c were provided to identify reliable improvement, deterioration, no change, and clinically significant change for each symptom. Changes in general depression and dysphoria were most strongly associated with changes in QoL and disability. The minimal clinically important difference values for the IDAS-II provide insights into perceived QoL and disability improvement without requiring additional measures. Tracking symptom changes and their implications for QoL and disability is useful in guiding evidence-based decisions in clinical practice. (PsycInfo Database Record (c) 2025 APA, all rights reserved)