Sleep schedule-dependent causes of insomnia and sleepiness in middle childhood and adolescence.

Schedule-dependent sleep problems tend to increase as the youngster moves from middle childhood through preadolescence and into adolescence. This is partly because the youngster becomes more independent and parental control over both the selection of particular sleep schedules and the consistent maintenance of these schedules across weekends diminishes. Even accurate descriptions of the existing problem may become difficult to obtain. Nevertheless, specific syndromes are common and may be identified and treated. There may be increased demands at both ends of the sleep period leading to later bedtimes, earlier wakings, insufficient sleep, and daytime sleepiness. Periods of wakefulness confined to one portion of the night (beginning, middle, or end) may occur if sleep requirements are overestimated. Insomnia coupled with trouble waking may imply a circadian phase shift abnormality or a 'school-refusal' variant. And, variable sleep difficulties may be seen in a youngster with irregular schedules and poor sleep hygiene. Guidelines to the understanding, evaluation, and treatment of these syndromes are presented.