抄録
Epidemiologic studies have clearly shown that sleep problems are common in the general population. A survey, conducted in Japan, reported that 21.4% of adults had complaints of insomnia and that 14.9% complained of hypersomnia (excessive daytime sleepiness). In the primary care setting, however, few patients present with overt sleep complaints but rather generally present with symptoms of fatigue, excessive sleepiness, and impaired waking. Therefore, it is important for physicians to understand how to differentiate and manage the sleep complaints of the patient. Herein, the author reviewed the clinical management of insomnia and hypersomnia, together with recent pathophysiological findings on these disorders. Insomnia is currently defined as an inability to obtain an adequate amount of sleep, to feel restored and refreshed in the morning, and to function adequately in the daytime. The differential diagnosis of difficulty in sleeping includes psychophysiological, neurological and circadian causes. Pharmacological and non-pharmacological interventions are combined in the treatment of insomnia. Sleep deprivation is the most frequent cause of excessive daytime sleepiness. Narcolepsy is the most prevalent type of hypersomnia with sleep attack and cataplexy. Recent studies have indicated the pathogenetic importance of orexin/hypocretin (a peptide hormone produced in the lateral hypothalamus) dysfunction in narcolepsy.
