Factor structure of the hospital anxiety and depression scale in older patients with major depression

Symptomatic anxiety has prognostic significance in major depression. In theory, the Hospital Anxiety and Depression Scale (HADS) should be a useful instrument for measuring the severity of symptomatic anxiety in late-life depression. However, the dimensional structure of the HADS has not been evaluated in elderly depressed patients; it is not known whether the scale actually functions as a bidimensional measure of anxiety and depression in this population. The purpose of this exploratory study, therefore, was to examine the factor structure of the HADS in older patients with major depression.

The HADS was completed by 213 patients, aged 60 years or older, with DSM-III-R unipolar major depression. Principal components analysis was performed on the full 14-item HADS and on each of its subscales.

Two distinct factors, which corresponded to the instrument's depression and anxiety subscales, emerged. The two-factor structure proved reasonably stable when the study group was randomly divided into two halves. Analysis of the subscales resulted in a single factor for each. The subscales had high internal reliability.

These findings confirm that the HADS functions as a bidimensional measure of depression and anxiety in older patients with major depression. The results suggest that the HADS is a valid instrument for measuring severity of anxiety, independent of other depressive symptoms, in this population.