The Effects of Fluoxetine on Quantitative Sleep EEG in Depressed Outpatients

M ajor depressive disorders (MDD) are associated with a variety of sleep macroarchitectural disturbances, based on visual stage scoring of the sleep electroencephalogram (EEG). These include insomnia, impaired sleep continuity, abnormalities in the amount and timing of rapid eye movement (REM) sleep, reductions in deep non-REM (NREM) sleep, increased awakenings during the night and increased light, nonrestorative Stage 1 sleep (1-3). Clinically depressed patients also show a number of sleep microarchitectural abnormalities, based on quantitative EEG measurement. Reductions in the amplitude, incidence and distribution of delta activity across NREM sleep have been the most consistent findings (3-11), although not all studies support this finding (12-13). Sleep microarchitectural abnormalities are also found in faster frequency EEG bands including alpha (11), beta (3, 4-15) and in total EEG power (11). Those with MDD show greater amplitude and incidence of fast-frequency EEG activity during sleep than healthy controls. Of particular interest is the finding that women with MDD appear to have the highest incidence of fast-frequency EEG activity during sleep, yet show more delta activity than depressed men (16-17). Moreover, depressed patients particularly women also show a reduction in temporal coherence of ultradian EEG rhythms (14,17-18). The Effects of Fluoxetine on Quantitative Sleep EEG in Depressed Outpatients