A critical review of sleep and its disorders from a developmental perspective.

A review of EEG sleep physiology and disorders of sleep is presented from a developmental perspective. After sleep physiology is reviewed in relation to the aging process, with various sleep changes considered as possible signs of normal or pathological aging, sleep disorder characteristics of different parts of the life cycle and/or the ontogenetic aspects of sleep disorders per se are also described. This review highlights the need for four diverse but related areas of research: (1) longitudinal studies to describe the natural history of primary sleep disorders; (2) controlled treatment and outcome studies; (3) additional epidemiologic inquiries using the currently available systematic nosology of sleep-wake disorders; and (4) further neurochemical and chronobiological investigation of basic mechanisms potentially involved in age-related sleep changes.