Serial monitoring of antidepressant response to electroconvulsive therapy with sleep EEG recordings and dexamethasone suppression tests.

The study of the biological correlates of major depressive disorder (MDD) has received great impetus in recent years. Electroencephalographic (EEG) sleep measurements and the Dexamethasone Suppression Test (DST) have been among the most studied and productive of these biological correlates. Commonly described EEG sleep abnormalities in MDD include shortened rapid eye movement (REM) latency, increased REM density, decreased delta sleep, decreased sleep efficiency, and decreased total sleep time (Kupfer and Thase 1983; Gillin et al. 1984). With EEG sleep measurements, used individually or through discriminant analysis, the sensitivity, specificity, and diagnostic confidence for primary endogenous depression ranges from 61% to 90%, 80% to 100%, and 83% to 100%, respectively (Kupfer and Thase 1983). Similar findings have been described for the DST in MDD (Carroll et al. 1981). Thus, both the sleep EEG and the DST can be used to support the