A psychiatric perspective on insomnia.

Insomnia is a cardinal symptom for many psychiatric disorders, especially depressive disorders. Treatment of the underlying psychiatric disorder may be sufficient to relieve the accompanying insomnia. If the insomnia fails to respond, then consideration should be given to the possibility of inadequate treatment of the primary psychiatric disorder, iatrogenic insomnia, insomnia related to a medical disorder, or learned/habit insomnia. Persistent insomnia should be aggressively pursued, since it has been associated with a variety of adverse outcomes in samples of depressed patients. The physician should always inquire about and encourage healthy sleeping behaviors, even if hypnotic medication is contemplated. Benzodiazepines and nonbenzodiazepine benzodiazepine receptor agonists (BzRAs) have the best evidence for efficacy as hypnotics, although sedating antidepressants are popularly prescribed. Although all benzodiazepine hypnotics and nonbenzodiazepine BzRAs are comparably efficacious in inducing sleep, they vary markedly in their potential for residual side effects.