Postdexamethasone cortisol levels and subgroups of affective illness.

Abstract

To the Editor.— In their recent article on the use of biological markers in the assessment of patients with endogenous depression, Feinberg and Carroll 1 found that unipolar depressed patients with endogenous depression had higher mean postdexamethasone cortisol values than their bipolar counterparts. In contrast, no differences were found in sleep studies between the two groups. Our group had previously reported differences on dexamethasone suppression test (DST) results between unipolar and bipolar depressed patients. 2,3 It is thus gratifying to see a confirmation of our finding by these investigators. Prior to our reports, 2,3 studies in the literature had generally failed to find significant differences between unipolar and bipolar patients in 4PMpostdexamethasone cortisol levels. 4,5 Papakostas and associates 6 found that 14 of 20 unipolar depressed patients were nonsuppressors, in contrast with zero of four bipolar depressed patients. In our study 2 a higher percentage of unipolar (61%)