NORMAL CHANGES WITH AGING
Several changes occur in the nature of sleep that ac- companies aging. The need for sleep remains about the same, but the character of sleep changes. Older adults ex- perience lighter, more interrupted sleep. They spend more time in Stage 1 than younger adults and also experience a decrease in Stages 3 and 4, the periods of deep, most restorative sleep. The amount of time in REM sleep stays about the same but occurs earlier in the sleep cycle.
The amplitude of the circadian rhythm declines with age because of diminished body temperature and mela- tonin production rhythms. Older adults also tend to wake up at a time closer to their body temperature minimum, which seems to be phase-advanced, especially in elderly women who go to bed earlier and wake up earlier. Much of the insomnia resulting from early morning awakenings reflects circadian effects.4
Although the age-related physiologic changes that af- fect the elder’s sleep lead to more fragile, easily inter-