The short‐form version of the Depression Anxiety Stress Scales (DASS‐21): Construct validity and normative data in a large non‐clinical sample

TLDR

The study examined whether the DASS‑21 stress scale reflects negative affectivity or a distinct construct and supplied normative data for the general adult population. Using a cross‑sectional sample of 1,794 UK adults, the authors performed confirmatory factor analysis that identified a quadripartite model comprising a general distress factor and separate orthogonal depression, anxiety, and stress factors. The quadripartite model fit significantly better than a negative‑affectivity‑only model, confirming that DASS‑21 subscales validly measure distinct depression, anxiety, and stress dimensions while also reflecting general psychological distress, and the large normative dataset improves its practical utility.

Abstract

To test the construct validity of the short-form version of the Depression anxiety and stress scale (DASS-21), and in particular, to assess whether stress as indexed by this measure is synonymous with negative affectivity (NA) or whether it represents a related, but distinct, construct. To provide normative data for the general adult population.Cross-sectional, correlational and confirmatory factor analysis (CFA).The DASS-21 was administered to a non-clinical sample, broadly representative of the general adult UK population (N = 1,794). Competing models of the latent structure of the DASS-21 were evaluated using CFA.The model with optimal fit (RCFI = 0.94) had a quadripartite structure, and consisted of a general factor of psychological distress plus orthogonal specific factors of depression, anxiety, and stress. This model was a significantly better fit than a competing model that tested the possibility that the Stress scale simply measures NA.The DASS-21 subscales can validly be used to measure the dimensions of depression, anxiety, and stress. However, each of these subscales also taps a more general dimension of psychological distress or NA. The utility of the measure is enhanced by the provision of normative data based on a large sample.