Supplementary file 2_Psychometric validation of the revised Chinese version of the Dimensional Anhedonia Rating Scale in psychiatric outpatients.docx

ObjectiveTo refine the Chinese version of the Dimensional Anhedonia Rating Scale (DARS) and evaluate the psychometric properties of the Revised Chinese DARS (RC-DARS) in a large sample of first-visit psychiatric outpatients.
MethodsThe study was conducted in two sequential phases at a specialized psychiatric hospital. In Phase I (n = 277), the existing Chinese DARS underwent semantic and cultural refinement in accordance with ISPOR and TRAPD guidelines, incorporating cognitive interviews and back-translation procedures. In Phase II (n = 788), the RC-DARS was administered alongside the Self-Rating Depression Scale (SDS), Self-Rating Anxiety Scale (SAS), Pittsburgh Sleep Quality Index (PSQI), and the MMPI Suicide Ideation Subscale (MMPI-SI). Exploratory and confirmatory factor analyses were conducted using common-factor extraction and the WLSMV estimator for ordinal indicators. Internal consistency, gender-based measurement invariance, and convergent validity were evaluated.
ResultsExploratory analyses supported a four-factor domain structure. Confirmatory factor analysis demonstrated good model fit for the domain-based model (χ²/df = 3.81, CFI = 0.98, TLI = 0.97, RMSEA = 0.08, SRMR = 0.05), with substantially superior fit relative to an alternative reward-processing model. Internal consistency was excellent (Cronbach’s α = 0.95; McDonald’s ω = 0.96). Multi-group analyses supported configural, metric, and scalar invariance across gender (ΔCFI < 0.01). RC-DARS total scores were significantly negatively correlated with depressive symptoms (r = −0.443), anxiety (r = −0.317), sleep disturbance (r = −0.494), and suicide risk (r = −0.312) (all p <.001). Individuals with severe depressive symptoms exhibited significantly lower RC-DARS scores than those below the clinical threshold.
ConclusionsThe RC-DARS demonstrates robust psychometric properties in a first-visit outpatient sample. The revision primarily enhances semantic precision and structural differentiation without materially altering score distributions. The scale may serve as a refined instrument for dimensional assessment of anhedonia in similar clinical contexts, pending longitudinal and multi-site validation.