Sleep disorders and insomnia.

Primary sleep disorders include narcolepsy, the Pickwickian syndrome, sleep apnea in infants and other rare conditions. Secondary sleep disorders occur in depression, alcoholism, endocrinopathies, heart failure and pregnancy. Medical symptomatology often increases during rapid-eye-movement (REM) sleep, when physiologic activity is high. Insomnia, the most common sleep disorder, requires careful work-up, attempts at environmental manipulation and judicious short-term pharmacotherapy. Pharmacologic manipulation of sleep is beset with complications. A basic understanding of properties and side effects of the sleep-inducing drugs is needed in order to select the optimal agent.