Recent research in sleep disorders has led to a better understanding of the causes and treatment of insomnia. A clearer understanding of the actions and side effects of sedative-hypnotic medications has led to a decrease in their use. Treatment of insomnia should be based on the following principles: (1) referral of individuals who are dangerous to themselves or others, (2) active treatment of psychiatric illness, (3) treatment of underlying disease, (4) use of nondrug treatment modalities and (5) restriction of the use of hypnotics to the treatment of transient insomnia.