A confirmatory factor analysis of the Hospital Anxiety and Depression scale: Comparing empirically and theoretically derived structures

Objectives, To compare the fit of various factor solutions for the Hospital Anxiety and Depression scale (HRD; Zigmond & Snaith, 1983). Design. A cross-sectional postal sun ey was used to collect the data from c ommunity-based participants in the West of Scotland Twenty-07 study. Methods. The HAD scale, a 14-item self-administered measure of anxiety and depression, was completed by 2547 participants from three age cohorts (aged approximately 18, 39 and 58 years). Using confirmatory factor analyses fou r models suggested by prior exploratory factor analyses were compared to a model derived from Clark and Watson's (1991) tripartite: theory of anxiety and depression. Results. The model derived from the tripartite theory of anxiety and depres sion (with factors labelled negative affectivity, anhedonic depression and autonomic anxiety) produced the closest tit to the: data. This model produc ed a good fit in ail three cohorts although group comparisons suggested tha t there were variations in the strength of some factor loadings across the three age groups. A model that had a hierarchical arrangement of the three factors in the tripartite model was also produced. This model fit the data equally as well as did the 'flat' tripartite model. Conclusions. Three factors appear to underlie the HAD scale. Research is ne eded that examines whether or not using sub-scales based on these factors i ncreases the ability of the HAD scale to detect cases of anxiety and depres sion.