Prevalence of insomnia in various psychiatric diagnostic categories.

Sixty percent of 536 new referrals to a psychiatric clinic at a general hospital complained of insomnia. Prevalence was high in all psychiatric categories, especially in physiologic disorders, somatoform disorders and mood disorders, followed by epilepsy. Complaints of difficulty in falling asleep were high in the physiologic and somatoform disorder groups. Complaints of nocturnal awakening were high in the anxiety and physiologic disorder groups, while complaints of early morning awakening were high in the organic and mood disorder groups. Prescription rates of hypnotics was most prevalent in the mood and adjustment disorder groups, whereas a non-pharmacological approach, including psychological education and behavioral therapy, was applied mainly to the physiologic disorder group.