Psychiatric diagnoses of patients visiting a sleep disorder clinic due to dyssomnias

This study analyzed the demographic characteristics and psychiatric diagnoses of 90 consecutive patients who visited a sleep disorder clinic in Taiwan with complaints of insomnia (difficulty initiating or maintaining sleep, or nonrestorative sleep) or hypersomnia (excessive sleepiness as evidenced by either prolonged sleep episodes or daytime sleep episodes that occur almost daily). All subjects were interviewed using a sleep disturbance questionnaire and the structured Mini-International Neuropsychiatric Interview supplemented by the DSM-IV criteria for psychiatric diagnoses. Among 90 patients, 79 were classified as having insomnia and 11 had hypersomnia. 53 patients also had psychiatric diagnoses other than sleep disorders. Patients with insomnia had a significantly higher rate of comorbidities with other psychiatric diagnoses (65.8%) than did subjects with hypersomnia (9.1%). These results emphasize the importance of psychiatric evaluation of patients with complaints of sleep disturbance.