Microstructure of sleep in depressed patients according to the cyclic alternating pattern.

BACKGROUND: The aim of this study was to evaluate the microstructure of the EEG sleep of depressed subjects by cyclic alternating pattern (CAP) analysis. METHODS: 78 patients affected by major depression and 18 control subjects matched for age and sex underwent a full night polysomnographic study. RESULTS: A significant increase in CAP rate (60 versus 35%) was found in the patients group compared to controls while no significant difference was found with the traditional analysis. CONCLUSION: In depressed subjects CAP analysis is able to show a microstructural sleep impairment, which is not evident at the macrostructural level, providing an objective measure of sleep disturbance in those patients.