Electrographic analysis of the sleep cycle in young depressed patients

Electrographic (EEG) patterns of nocturnal sleep were investigated in young psychiatric patients during unipolar depressive episodes. EEG-sleep data was recorded in 20 non-psychotic depressed patients all under 26 years old individually matched with a normal control group. All 20 subjects slept in the laboratory for 1-3 consecutive baseline nights from 12-8:00 a.m. During a subsequent extended condition 14 in each group were allowed to sleep ad-lib. Although the mean total time asleep on baseline nights was about the same between groups (greater than 7.1 hr), the depressives had a statistically significant reduction in REM time, increased transitions into stage 1, but most especially averaged: (a) less stage 4; and (b) more stage 1. Compared with the prior eight-hour night 27/28 subjects among both groups exhibited elevated time asleep during the extended condition, but the patients' mean total 10.3 hr sleep was significantly greater by 1.5 hr than the controls (X = 8.8 hr). Sleep exceeding 9 hr on the ad-lib night was a consistent phenomenon which occurred in significantly more (11/14) young depressed patients contrasted to 4/14 control subjects. These findings indicate that young persons with primary affective disorders do not exhibit nocturnal EEG disturbances of comparable severity to most older depressed patients such as reduced time asleep, increased wakefulness or lowered slow-wave (stages 3 and 4) sleep. Although no direct evidence of symptomatic 'hypersomnia' in these patients was provided, the present results demonstrated that some young persons with clinical depression have the capacity to sleep for sustained periods.