Studies of sleep in the elderly.
D000368:Aged; D000375:Aging; D003863:Depression / Q000150:complications / Q000628:therapy; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008297:Male; D012647:Self-Assessment; D012890:Sleep; D012894:Sleep Stages; D012893:Sleep Wake Disorders / Q000209:etiology / Q000628:therapy; D012895:Sleep, REM; D013997:Time Factors; D014851:Wakefulness