Sleep and treatment response in depression: new findings using power spectral analysis

This study examined quantitative measures of sleep electroencephalogram (EEG) and phasic rapid eye movements (REM) as correlates of remission and recovery in depressed patients. To address correlates of remission, pre-treatment EEG sleep studies were examined in 130 women outpatients with major depressive disorder treated with interpersonal psychotherapy (IPT). To address correlates of recovery, baseline and post-treatment EEG sleep studies were examined in 23 women who recovered with IPT alone and 23 women who recovered with IPT+fluoxetine. Outcomes included EEG power spectra during non-rapid eye movement (NREM) sleep and REM sleep and quantitative REMs. IPT non-remitters had increased phasic REM compared with remitters, but no significant differences in EEG power spectra. IPT+fluoxetine recoverers, but not IPT recoverers, showed increases in phasic REM and REM percentage from baseline to recovery. In NREM sleep, the IPT+fluoxetine group showed a decrease in alpha power from baseline to recovery, while the IPT group showed a slight increase. The number of REMs was a more robust correlate of remission and recovery than modeled quantitative EEG spectra during NREM or REM sleep. Quantitative REMs may provide a more direct measure of brainstem function and dysfunction during REM sleep than quantitative sleep EEG measures.