Delusional depression, family history, and DST response: a pilot study.

Results of the Dexamethasone Suppression Test (DST), performed on 65 patients with major unipolar depression, were classified both by suppression versus nonsuppression and by three ranges of postdexamethasone cortisol levels. Subgroups of patients were then compared for familial prevalence for depression and alcoholism and for delusional symptomatology. A strong association emerged among high postdexamethasone cortisol levels, a significantly increased familial prevalence for depression, and the presence of delusions in probands. In this study, ranges of DST responses were superior to suppression versus nonsuppression criteria alone in defining this subgroup.