Effects of regularizing sleep-wake schedules on daytime autonomic functions and psychological states in healthy university students with irregular sleep-wake habits

Abstract

The present study examined the effects of regularizing sleep–wake schedules on sleep, autonomic function and mood/emotional and personality states in 14 habitually irregular sleepers. During the experiment, sleep monitoring and regularized sleep–wake schedules were conducted at home. First, the subjects' habitual sleep–wake patterns were strictly monitored for 6 days (Session 1); second, subjects' irregular sleep–wake patterns were regularized for 6 days (Session 2); and finally, subjects reverted from their regularized sleep–wake schedules to their original, habitual sleep–wake schedules and were monitored for 6 days (Session 3). Assessments in the laboratory, which were conducted in the daytime, were repeated four times. The first three assessments were carried out on the days following Sessions 1, 2, and 3. The fourth measurement (Session 4), which was conducted under the original irregular sleep–wake pattern condition, was performed approximately 6 months after initiation of the second irregular sleep–wake schedule. In results, significant reductions in daytime parasympathetic activity and negative mood, i.e. tension–anxiety, anger–hostility, and fatigue, were observed after the 6‐day regularized sleep–wake schedule and extending through Session 3. However, the parasympathetic activity, as well as negative mood manifestations, returned to their initial levels when measured 6 months later. On the other hand, sleep and personality states did not change in response to alternations in sleep–wake regularity. However, the reduction of daytime fatigue level suggests a possibility that further sleep improvements might be difficult to detect under the regularized sleep–wake schedule because the subjects were healthy university students without sleep disorders.

Timing and variability of postpartum sleep in relation to daytime performance

“…Healthy adults on a more consistent sleep schedule have improved sleep quality [22,43], performance [22], and mood [23]. Among insomniacs, stabilizing the sleep period has also lead to improved sleep [44,45].…”

“…Among healthy adults, maintaining a consistent sleep schedule is associated with shorter reaction times, better affect, and more time spent in slow wave and rapid eye movement sleep than healthy adults who maintain an irregular sleep schedule [22]. When sleep-wake schedules were experimentally regulated among a population of healthy university students with highly irregular sleep-wake habits, improvements in mood and reductions in daytime parasympathetic activity were noted [23]. This association between a stable sleep schedule and better heath and performance suggests these relations might also account for some variance in postpartum daytime functioning.…”

The role of sleep hygiene in promoting public health: A review of empirical evidence

“…Similarly, Takasu and colleagues assigned a rigid sleep schedule to 14 college students with irregular baseline sleep timing and found no significant changes in actigraphy-assessed sleep or self-reported sleepiness and alertness after 6 days. 109 Neither study recruited participants based on presence of sleep problems which, combined with small sample sizes, could explain these null findings. Youngstedt and colleagues recruited a sample of older adults with long self-reported sleep duration to examine the effect of a 90-minute reduction of time in bed.…”

Wake up Call for College Administrators Regarding Students’ Sleep Disturbance and Academic Performance

“…This allows for the advanced sleep readiness times that typically peak in adolescence/young adult to guide the sleepers' readiness for sleep and insure a sufficient sleep interval opportunity [1]. While not widely adopted, the advanced start time on first classes of the day which are typically the designation of lower classman, constructively attends to the prevalence need of the young adult college student with poor sleep quality [4][5][6][7]. The use of student services directed by college administrators has resulted, recently, in an increased use of mental health services and need for psychiatric medication management [1,4,5].…”