Pharmacological Treatment of Insomnia

Abstract

Insomnia is the most common sleep-related complaint and the second most common overall complaint (after pain) reported in primary care settings. It affects 35% of the general population, according to the 1984 report of the National Institutes of Mental Health (1). Insomnia is not defined by total sleep time but by the inability to obtain sleep of sufficient length or quality to produce refreshment the following morning. For example, a person who needs only 4 hours of sleep does not have insomnia if he or she is refreshed in the morning after having 4 hours of sleep, whereas someone who needs 10 hours of sleep may have insomnia if he or she does not feel refreshed even after 8 hours of sleep. Contrary to popular lore, psychiatric or psychological factors are not the most frequent causes of insomnia. Insomnias can be divided into two major categories: the primary insomnias and the secondary insomnias. As discussed elsewhere in this volume, primary insomnias are conditions in which the insomnia is the main pathophysiological process, whereas secondary insomnias are conditions where the insomnia is a symptom of another disorder.