Sleep and affect in adolescents: Bidirectional daily associations over 28-day ecological momentary assessment

Monitoring Daily Sleep, Mood, and Affect Using Digital Technologies and Wearables: A Systematic Review

Background: Sleep and affective states are closely intertwined. Nevertheless, previous methods to evaluate sleep-affect associations have been limited by poor ecological validity, with a few studies examining temporal or dynamic interactions in naturalistic settings. Objectives: First, to update and integrate evidence from studies investigating the reciprocal relationship between daily sleep and affective phenomena (mood, affect, and emotions) through ambulatory and prospective monitoring. Second, to evaluate differential patterns based on age, affective disorder diagnosis (bipolar, depression, and anxiety), and shift work patterns on day-to-day sleep-emotion dyads. Third, to summarise the use of wearables, actigraphy, and digital tools in assessing longitudinal sleep-affect associations. Method: A comprehensive PRISMA-compliant systematic review was conducted through the EMBASE, Ovid MEDLINE(R), PsycINFO, and Scopus databases. Results: Of the 3024 records screened, 121 studies were included. Bidirectionality of sleep-affect associations was found (in general) across affective disorders (bipolar, depression, and anxiety), shift workers, and healthy participants representing a range of age groups. However, findings were influenced by the sleep indices and affective dimensions operationalised, sampling resolution, time of day effects, and diagnostic status. Conclusions: Sleep disturbances, especially poorer sleep quality and truncated sleep duration, were consistently found to influence positive and negative affective experiences. Sleep was more often a stronger predictor of subsequent daytime affect than vice versa. The strength and magnitude of sleep-affect associations were more robust for subjective (self-reported) sleep parameters compared to objective (actigraphic) sleep parameters.

Bidirectional Associations Between Loneliness, Emotional Support, and Sleep in Daily Life

OBJECTIVE

Evidence suggests a link between positive social relationship perceptions and improved sleep (e.g., quality, efficiency) across the life span. Less work has probed the directionality of these relationships. Here, we report findings from the first study to examine bidirectional between- and within-person associations between loneliness and emotional support with daily life measures of sleep.

METHODS

Participants were 389 healthy adults aged 40 to 64 years (61% female) who completed hourly surveys assessing loneliness and perceptions of emotional support over the course of 4 days. Measures of actigraphy-assessed sleep and nightly sleep quality were also assessed for 7 to 10 days.

RESULTS

Individuals with lower average daily loneliness showed higher sleep quality and efficiency than individuals with higher loneliness (r = -0.19, p < .001; r = -0.14, p = .008, respectively), and greater average emotional support was likewise linked with better sleep quality (r = 0.18, p < .001). Controlling for neuroticism attenuated the effects of average loneliness on sleep. Within-person analyses showed unexpected bidirectional effects. Specifically, days in which people felt relatively lonelier were followed by nights with greater sleep efficiency (γ = 1.08, p = .015), and nights when people reported relatively poorer sleep quality were followed by days with greater emotional support (γ = -0.04, p = .013). These unexpected findings are probed in exploratory analyses.

CONCLUSIONS

Individuals with higher loneliness and lower emotional support report poorer sleep quality and efficiency, on average. Day-to-day fluctuations in perceptions of social relationships may affect the following night's sleep, and vice versa.

Vulnerability to sleep-related affective disturbances? A closer look at dysfunctional beliefs and attitudes about sleep as a moderator of daily sleep-affect associations in young people

STUDY OBJECTIVES

Sleep and affect are closely related. Whether modifiable cognitive factors moderate this association is unclear. This study examined whether Dysfunctional Beliefs and Attitudes about Sleep moderate the impact of sleep on next-day affect in young people.

METHODS

Four hundred and sixty-eight young people (205 adolescents, 54.1% female, M ± SDage=16.92 ± 0.87; 263 emerging adults, 71.9% female, M±SDage=21.29 ± 1.73) self-reported sleep and affect, and wore an actigraph for 7-28 days, providing >5000 daily observations. Linear mixed-effects models tested whether Dysfunctional Beliefs and Attitudes about Sleep moderated daily associations between self-reported and actigraphic sleep duration, sleep efficiency, and next-day affect on between- and within-person levels. Both valence (positive/negative) and arousal (high/low) dimensions of affect were examined. Covariates included age, sex, race/ethnicity, day of week, and previous-day affect.

RESULTS

Dysfunctional Beliefs and Attitudes about Sleep significantly moderated sleep and high arousal positive affect associations on between- but not within-person levels. Individuals with higher Dysfunctional Beliefs and Attitudes about Sleep (+1 SD) and lower average sleep duration (actigraphic: p = .020; self-reported: p = .047) and efficiency (actigraphic: p = .047) had significantly lower levels of high arousal positive affect. After adjusting for multiple comparisons, Dysfunctional Beliefs and Attitudes about Sleep did not moderate relationships between sleep duration and low arousal positive affect (p ≥ .340).

CONCLUSIONS

Young people with more unhelpful beliefs about sleep and shorter, or poorer, sleep may experience dampened levels of high arousal positive affect. DBAS may constitute a modifiable factor increasing affective vulnerability on a global but not day-to-day level. Intervention studies are needed to determine if changing Dysfunctional Beliefs and Attitudes about Sleep may reduce sleep-related affect disturbances in young people.

Day-to-day directional relationships between sleep duration and negative affect

OBJECTIVE

There is a strong association between sleep disturbance and negative affect. However, the day-to-day directional connections between sleep and negative affect remain unclear. We examined day-to-day relationships between sleep duration and negative affect in community adults.

METHODS

Participants were two subsamples of the Midlife in the United States Study (Sample 1: n = 2,022; Sample 2: n = 782). Daily negative affect and previous night sleep duration were assessed via end-of-day telephone interviews for eight days. Random intercept cross-lagged panel models tested sleep duration as a predictor of next-day negative affect and vice versa, controlling for age, gender, and race.

RESULTS

In both samples, shorter sleep duration predicted higher next-day negative affect, but daily negative affect was not a significant predictor of upcoming-night sleep duration. Follow-up analyses indicated that the relationship between sleep duration and negative affect was nonlinear. Sleeping fewer than 7.5 hours or more than 10.5 hours was associated with greater next-day negative affect than sleeping between 7.5 and 10.5 hours.

CONCLUSIONS

In two large samples of community adults, sleep duration unidirectionally predicted higher next-day negative affect, and this relationship was nonlinear. Sleeping at least 7.5 hours and no more than 10.5 hours appeared to be an optimal range associated with lowest next-day negative affect.

Measuring light regularity: sleep regularity is associated with regularity of light exposure in adolescents

STUDY OBJECTIVES

Light is the main time cue for the human circadian system. Sleep and light are intrinsically linked; light exposure patterns can influence sleep patterns and sleep can influence light exposure patterns. However, metrics for quantifying light regularity are lacking, and the relationship between sleep and light regularity is underexplored. We developed new metrics for light regularity and demonstrated their utility in adolescents, across school term and vacation.

METHODS

Daily sleep/wake and light patterns were measured using wrist actigraphy in 75 adolescents (54% male, 17.17 ± 0.83 years) over 2 weeks of school term and a subsequent 2-week vacation. The Sleep Regularity Index (SRI) and social jetlag were computed for each 2-week block. Light regularity was assessed using (1) variation in mean daily light timing (MLiT); (2) variation in daily photoperiod; and (3) the Light Regularity Index (LRI). Associations between SRI and each light regularity metric were examined, and within-individual changes in metrics were examined between school and vacation.

RESULTS

Higher SRI was significantly associated with more regular LRI scores during both school and vacation. There were no significant associations of SRI with variation in MLiT or daily photoperiod. Compared to school term, all three light regularity metrics were less variable during the vacation.

CONCLUSIONS

Light regularity is a multidimensional construct, which until now has not been formally defined. Irregular sleep patterns are associated with lower LRI, indicating that irregular sleepers also have irregular light inputs to the circadian system, which likely contributes to circadian disruption.

Why so slangry (sleepy and angry)? Shorter sleep duration and lower sleep efficiency predict worse next-day mood in adolescents

PURPOSE

The goal of this study was to evaluate the relationships of actigraphic nighttime sleep duration and quality with next-day mood among urban adolescents using a micro-longitudinal design.

METHODS

A subsample (N = 525) of participants from the Fragile Families & Child Wellbeing Study (mean age: 15.4 years; 53% female; 42% Black non-Hispanic, 24% Hispanic/Latino, 19% White non-Hispanic) in the United States between 2014 and 2016 concurrently wore a wrist actigraphic sleep monitor and rated their daily mood in electronic diaries for about 1 week. Multilevel models tested the within-person temporal associations of nightly sleep duration and sleep maintenance efficiency with next-day reports of happiness, anger, and loneliness. The models also tested the between-person associations of sleep variables and mood. Models adjusted for sociodemographic and household characteristics, weekend, and school year.

RESULTS

After nights when adolescents obtained longer sleep duration than their usual, they reported lower ratings of anger (B = -.03, p < .01) the next day. After nights when adolescents had higher sleep maintenance efficiency than their usual, they reported higher ratings of happiness (B = .02, p < .01) the next day. Adolescents who had longer average sleep duration reported lower ratings of anger (B = -.08, p < .01) and loneliness (B = -.08, p < .01) compared to others. There was no within-person association of sleep duration or efficiency with loneliness. Sleep duration was not associated with happiness between adolescents, and sleep maintenance efficiency was not associated with any mood measure between adolescents.

CONCLUSIONS

Improvements to nightly sleep may help increase happiness and decrease anger the following day in adolescents. Promoting sleep health is recommended to improve mood.

Objective and subjective sleep health in adolescence: Associations with puberty and affect

Sleep health tends to worsen during adolescence, partially due to pubertal-related changes that, in combination with social and psychological factors, can lead to long-lasting impairments in sleep health and affective functioning. Discrepant findings between subjective and objective measures of sleep in relation to affect have been reported in studies of adults; however, few investigations have assessed both subjective and objective sleep quality in a single sample, and fewer have examined this in the context of pubertal development. We aimed to (1) characterise pubertal associations with subjective sleep satisfaction, objective sleep efficiency, and objective and subjective sleep duration in adolescents; (2) examine the longitudinal association between daily affect and sleep metrics; and (3) test whether pubertal stage moderated this association. Eighty-nine participants (64% female, ages 13-20) completed an ecological momentary assessment (EMA) and actigraphy protocol. Independent of age, advanced pubertal stage was associated with lower subjective sleep satisfaction but not with objective sleep indices. Subjective sleep satisfaction was associated with within-person trajectories of negative affect, but not with positive affect. Pubertal stage and sleep satisfaction did not interact to predict within-day negative or positive affect. These findings are consistent with previous reports showing that objective and subjective sleep health are associated differently with puberty, and that subjective sleep health is associated with daily affect. Pubertal stage may be a more important indicator of subjective sleep quality in adolescence than is chronological age, most likely due to hormonal changes and psychological adjustment to the physical changes associated with the pubertal transition.

Prompt-level predictors of compliance in an ecological momentary assessment study of young adults' mental health

BACKGROUND

Ecological momentary assessment (EMA) has become a popular method of gathering information about participants as they go about their daily lives. However, participant non-compliance, especially non-random compliance, in EMA is a concern. Better knowledge of the moment-to-moment factors that predict prompt non-response can inform the design of strategies to mitigate it.

METHOD

We used data from a general population young adult (n = 260) EMA study, 'decades-to-minutes' (D2M) and fitted dynamic structural equation models (DSEMs) to explore a range of candidate momentary predictors of missing the next prompt.

RESULTS

We found that higher levels of stress, overall negative affect, and the specific negative affective state of 'upset' at a given prompt predicted a greater likelihood of missing the next prompt. However, no other specific affective states, alcohol use, experiencing social provocations nor aggressive behaviour predicted missing the next prompt.

LIMITATIONS

The primary limitation of the present study was a lack of information on predictors concurrent with missed prompts.

CONCLUSIONS

Findings point to the potential value of gathering information on momentary negative affect (especially feeling upset) and stress to help inform strategies that intervene to prevent application disengagement at optimal moments and to feed into strategies to mitigate bias due to non-random non-response in EMA studies.

Two-year changes in sleep duration are associated with changes in psychological distress in adolescent girls and boys: the fit futures study

Objective

Studies indicate an inverse association between sleep duration and psychological distress. We aimed to explore associations between changes in sleep duration and changes in psychological distress in girls and boys.

Methods

The Fit Futures Study is a broad adolescent study providing data from 373 girls and 294 boys aged 15–18 years collected in 2010/2011 (FF1) and 2012/2013 (FF2). Psychological distress was measured by the Hopkins Symptom Checklist (HSCL-10) and sleep duration was self-reported. Change score variables were calculated as the change between baseline and follow-up for sleep duration and HSCL-10, respectively. Associations between changes in sleep duration and changes in HSCL-10 were explored by linear regressions, in gender-stratified analyses.

Results

At FF1, girls and boys slept on average 6.93 (SD = 1.08) and 7.05 (SD = 1.20) hours per night respectively, and correspondingly, 6.83 (SD = 1.19) and 6.85 (SD = 1.21) at FF2. At FF1, 22.8% of the girls and 25.8% of the boys slept ≤ 6 h per night, and correspondingly 28.0% and 28.2% at FF2. In girls and boys, one unit increase (30 min) in sleep duration was associated with a decrease in HSCL-10 score of B [95% CI] = −0.090 [−0.131, −0.048], p < 0.001, and −0.054 [−0.091, −0.017], p < 0.001, respectively. The associations remained significant after adjusting for confounders.

Conclusion

Our findings show that increased sleep duration was associated with decreased psychological distress during adolescence. Future studies should examine the causality between sleep duration and psychological distress.

Contrasting Effects of Sleep Restriction, Total Sleep Deprivation, and Sleep Timing on Positive and Negative Affect

Laboratory-based sleep manipulations show asymmetries between positive and negative affect, but say little about how more specific moods might change. We report extensive analyzes of items from the Positive and Negative Affect Scale (PANAS) during days following nights of chronic sleep restriction (6 h sleep opportunity), during 40 h of acute sleep deprivation under constant routine conditions, and during a week-long forced desynchrony protocol in which participants lived on a 28-h day. Living in the laboratory resulted in medium effects sizes on all positive moods (Attentiveness, General Positive Affect, Joviality, Assuredness), with a general deterioration as the days wore on. These effects were not found with negative moods. Sleep restriction reduced some positive moods, particularly Attentiveness (also General Positive), and increased Hostility. A burden of chronic sleep loss also led to lower positive moods when participants confronted the acute sleep loss challenge, and all positive moods, as well as Fearfulness, General Negative Affect and Hostility were affected. Sleeping at atypical circadian phases resulted in mood changes: all positive moods reduced, Hostility and General Negative Affect increased. Deteriorations increased the further participants slept from their typical nocturnal sleep. In most cases the changes induced by chronic or acute sleep loss or mistimed sleep waxed or waned across the waking day, with linear or various non-linear trends best fitting these time-awake-based changes. While extended laboratory stays do not emulate the fluctuating emotional demands of everyday living, these findings demonstrate that even in controlled settings mood changes systematically as sleep is shortened or mistimed.