A common feature of aging is the advance of the timing of sleep to earlier hours, 1–7 often
earlier than desired. 8–10 The sleep of older people is also characterized by an increased
number of awakenings 11 and a reduction of the deeper stages of non–rapid eye movement
(REM) sleep (also called slow wave sleep [SWS], stages 3 and 4 sleep). 12–31 These age-
related changes are also associated with sleep complaints, with most studies finding that
more than one-third of older adults report early morning awakening and/or difficulty …