ACTIVITY AND BEHAVIORAL RHYTHM DISTURBANCES IN ADULTS WITH MENTAL-RETARDATION

In an institution for persons with mental retardation, annual surveys for 5 years revealed many with wake-sleep and other circadian and behavioral disturbances suggestive of hypothalamic damage. To determine the characteristics of these sleep-wake problems, we monitored 40 such individuals each for 24-hour periods. Sleep disturbances observed included very few hours of sleep, delays in sleep onset, multiple nightime awakenings, and were associated with abnormal daytime behaviors. Subjects described as having had sleep abnormalities and also other manifestations suggestive of hypothalamic dysfunction which included polydipsia (53%), hyperphagia (40%), and dysthermia (10%). They exhibited substantial aggressiveness, self-injurious behavior, destructive tendencies, inacceptable social behavior, and frequent stereotypy. Since many of these problems can now be safely defined as circadian/hypothalamic dysfunctions, it is suggested that new means of resetting their circadian rhythms will be worth of trial.