Extended sleep (hypersomnia) in young depressed patients.

To test the hypothesis that young depressed patients have prolonged rather than shortened sleep, 14 depressed patients aged 17-25 and age-matched normal control subjects were allowed to sleep as long as they wanted. All subjects increased their sleep over baseline values, but the extended sleep period of the depressed patients was almost twice as long as that of the control subjects. The distribution of sleep stages in the extended period did not differ. The depressed patients had changes in the length of REM periods similar to those of older subjects. The findings suggest an interaction between age, sleep, and depression.