Depressed patients often report problems sleeping, and epidemiologic evidence suggests that insomnia may precede the onset of depression. Insomnia is associated with marked impairment in quality of life and ability to function effectively. Many studies have indicated that patients with chronic sleep problems have impaired mood and that effective management of insomnia in depressed patients can markedly improve their depression. Diagnosis of insomnia is challenging because there can be many different causes and the clinical picture can be blurred by the presence of other psychiatric illnesses. Pharmacotherapy provides reliable and rapid relief from insomnia, whereas behavioral therapies help produce long-term improvement. For many years, benzodiazepines have been the mainstay of drug treatment for insomnia. However, these drugs have significant side effects, and tolerance and dependence have discouraged use. Many doctors use sedating antidepressants in low doses to treat chronic insomnia. However, there is little evidence supporting the efficacy of these agents, and many have adverse side effects, including impairment of sleep. The newer selective hypnotic drugs, including the imidazopyridines, may offer patients a better short-term alternative to benzodiazepines or sedating antidepressants.