ELECTROENCEPHALOGRAPHIC SLEEP PROFILES IN SINGLE-EPISODE AND RECURRENT UNIPOLAR FORMS OF MAJOR DEPRESSION .1. COMPARISON DURING ACUTE DEPRESSIVE STATES

The current study uas conducted to examine if recurrent depression is associated with more severe disturbances of all-night EEG sleep profil es than single-episode depressions. Unmedicated sex- and age-matched g roups of 22 single-episode (SE) and 44 recurrent unipolar (RU) outpati ents with DSM-III-R/SADS/RDC major depression underwent 2 consecutive nights of EEG sleep recording. Multivariate analyses of covariance (MA NCOVAs) and/or analyses of covariance (ANCOVAs) were performed on six sets of sleep measures. Recurrent unipolar depression was associated w ith significantly increased phasic REM sleep, as well as increased REM counts on the second night of study. Recurrent depression also was as sociated with significantly poorer sleep efficiency, although the grou ps did not show consistent differences in sleep architecture or slow-w ave sleep. Our findings generally support the hypothesis that recurren t depression is associated with a more severe neurophysiologic substra te than phenotypically similar SE cases. Results are, for the most par t, compatible, with Post's (1992) model of illness progression, partic ularly with respect to greater disturbances of state-dependent sleep a bnormalities in the RU cases. Longitudinal studies are needed to confi rm the evolution of such changes prospectively.