Twenty-four-hour sleep-wake function and personality patterns in chronic insomniacs and healthy controls.

A comparison was made between 16 middle-aged chronic insomniacs and 16 normal sleepers, matched by age and sex, in a psychophysiological study, including polysomnographic night sleep recordings, MMPI personality profiles, testing of cognitive performance, and relaxation capability during daytime. Both objective and subjective criteria of night sleep demonstrated a clear separation of the two groups. Insomniacs had psychosomatic personality profiles. A test for unintentional sleep suggested that poor sleep function in insomniacs is related to deficient sleep-controlling mechanisms, rather than psychological trait and state factors. Only sleep onset difficulties were susceptible to situational factors. Daytime performance was not generally impaired in insomniacs, but they had greater difficulties in the morning. Subjective daytime sleepiness was significantly higher and might represent a particular psychological problem for active behavior. Interrelations of various deficiencies in sleep-wake behavior seem to delineate specific aspects of the chronic insomniac syndrome.