Interaction between personal sleep-wake rhythms and psychiatric hospital rest-activity schedule

A sample of 35 psychiatric inpatients were matched on gender and psychiatric diagnosis with 35 psychiatric outpatients. Both groups were given the Self-Assessment Questionnaire to Determine Morningness-Eveningness (Horne & Ostberg, 1976), and asked to record their sleep-wake patterns on a modified form of the Lewis and Masterton Sleep Chart (1957). The purpose was to explore the interactions between individual circadian rhythms of sleep and wakefulness and the hospital's rest-activity schedule. As hypothesized, inpatients slept less than outpatients (p = less than .05), but the mean total sleep time of evening types was not different from morning types. Circadian type was a good predictor of times of falling asleep and awakening for outpatients but not for inpatients, whose schedules appeared to be phase shifted by the hospital's rest-activity schedule. It was concluded that the theory of interacting rhythms guiding the study requires reformulation and that further research regarding the positive or negative effects of phase shifting is needed.