Does the dexamethasone suppression test relate to subtypes, factors, symptoms, or severity?

Abstract

Results of the dexamethasone suppression test (DST) are frequently abnormal in depression but not always. We performed the DST in 95 depressed inpatients to determine whether abnormal DST results were associated with individual symptoms of depression, latent behavioral "factors," melancholia, or severity of depression. Initial insomnia, agitation, loss of sexual interest, and weight loss correlated significantly with nonsuppression. Using multiple regression, these four symptoms contributed independently to the variance in DST results and more closely associated with the DST results than did severity or the diagnosis of melancholia or endogenous subtype. Factor analysis failed to identify a factor that correlated with the DST results more significantly than did the individual symptoms. Our findings and a literature review suggest that DST nonsuppression associates with certain vegetative signs of depression but not with such symptoms as loss of interest or anhedonia nor with "psychological" symptoms such as guilt, worthlessness, helplessness, hopelessness, or suicidal ideation.