Polysomnographic and MMPI characteristics of patients with insomnia.

This report represents the polysomnographic aspects of sleep and the psychological characteristics of a large series of patients with insomnia classified according to the diagnostic system of the Association of Sleep Disorders Centers. The findings for patients in the various diagnostic categories were compared to those of symptomatic patients with no objective findings. 9 specific diagnoses were made, but 4 diagnoses accounted for the majority of patients. The 4 most prevalent were psychophysiological disorders (15%), psychiatric disorders (17%), nocturnal myoclonus and restless legs (18%), and no objective findings (19%). Patients of a sleep disorders center are a select population and may not be representative of the general population of patients with insomnia complaints. The psychological characteristics of the different diagnostic groups were assessed by computing the number of elevations on the MMPI. Patients with a psychiatric diagnosis exhibited the highest number of MMPI elevations, as might be expected. Patients with nocturnal myoclonus had the lowest number of elevations. The other groups did not significantly differ from the group with no objective findings. Polysomnographic measures of sleep differed considerably among the diagnostic groups. The groups with medical disorders, respiratory impairment, atypical polysomnographic features, and nocturnal myoclonus had similar short sleep latencies to those of the group with no objective findings. With longer wake times before sleep and significantly different from patients with no objective findings were the psychophysiological disorder, psychiatric disorder and drug and alcohol groups. Patients with a circadian rhythm disturbance had the longest latencies.(ABSTRACT TRUNCATED AT 250 WORDS)