No abstract

Sleep has been linked to the daily patterns of stress-responsive physiological systems, specifically the hypothalamic–pituitary–adrenal (HPA) axis and autonomic nervous system (ANS). However, extant research examining sleep and diurnal patterns of cortisol, the primary end product of the HPA axis, has primarily focused on sleep duration with limited attention on other facets of sleep. For example, it is not clear how specific aspects of sleep (e.g., sleep quality, sleep duration variability) are related to specific components of diurnal cortisol rhythms. Salivary alpha-amylase (sAA) has been recognized as a surrogate marker of ANS activity, but limited research has explored relations between sleep and sAA diurnal rhythms. The current study utilized an ecological momentary assessment protocol to examine within- and between-person relations between several facets of sleep behavior using multiple methods (e.g., subjective report, actigraphy) and salivary cortisol and sAA. Older adolescents (N = 76) provided saliva samples and diary entries five times per day over the course of three days. Sleep was assessed via questionnaire, through daily diaries, and monitored objectively using actigraphy over a four day period. Between-person results revealed that shorter average objective sleep duration and greater sleep duration variability were related to lower levels of waking cortisol and flatter diurnal slopes across the day. Within-person results revealed that on nights when individuals slept for shorter durations than usual they also had lower levels of waking cortisol the next day. Sleep was not related to the cortisol awakening response (CAR) or diurnal patterns of sAA, in either between-person or within-person analyses. However, typical sleep behaviors measured via questionnaire were related to waking levels of sAA. Overall, this study provides a greater understanding of how multiple components of sleep, measured in naturalistic environments, are related to cortisol and sAA diurnal rhythms, and how day-to-day, within-person changes in sleep duration contribute to daily variations in cortisol.

The college transition is uniquely challenging for many first-year students. Few studies have investigated developmental change in students' adjustment across this brief, but significant transition, nor the daily interpersonal dynamics that are associated with adjustment across this same time. Guided by ecological and stage-environment fit frameworks, this study examined trajectories of first-year students' positive and negative affect across the transition to college. Further, we examined daily interactions with parents and friends as predictors of these trajectories. Participants were 146 first-year college students from a large southwestern university entering their first semester of college (M age ϭ 17.82, SD ϭ 0.50). Electronic ecological momentary assessments (EMAs) were administered to students twice weekly (maximum 49 observations) from July to December to assess daily experiences during the transition to college and across the first semester. Multilevel growth analyses showed that students reported a meaningful decrease in positive affect across the first semester, but stable levels of negative affect. Involvement and conflict with parents and friends predicted variability in these average changes, as well as daily affective states. As expected, greater involvement with parents and friends was associated with greater positive and less negative affect, and reports of conflict with parents and friends predicted negative affect experiences. Together, these findings suggest the importance of support from parents and friends during the initial adaptation to college, as well as the potential undermining role of conflict with significant others.

No abstract

Anxious youth typically experience sleep-related difficulties, but little is known about the role children's coping and perceived control over anxiety may play in these relations. We examined children's perceived levels of control over external anxiety-provoking events and internal anxious emotional reactions, as well as two dispositional coping tendencies (avoidant, support-seeking), and whether these were associated with anxious children's (N = 86) presleep arousal. Low perceived control over anxiety was significantly associated with high levels of presleep arousal. For children with low perceived control, higher avoidance was associated with greater presleep arousal, whereas lower avoidance was associated with lower presleep arousal levels. Findings suggest that efforts to avoid stressful life events may contribute to presleep arousal, especially under conditions where anxious arousal seems uncontrollable.