Bi-directional relations between stress and self-reported and actigraphy-assessed sleep: a daily intensive longitudinal study

Associations between habitual sleep characteristics and cardiometabolic disease risk in corporate executives

OBJECTIVES

Corporate executive job demands may lead to poor sleep habits, increasing their risk for cardiometabolic disease. This study aimed to describe and explore associations between objectively measured habitual sleep characteristics and cardiometabolic disease risk of corporate executives, while accounting for occupational, psychological, and lifestyle factors.

METHODS

Habitual sleep was measured using wrist-worn actigraphy and a sleep diary over seven consecutive days in 61 (68.3% men) corporate executives aged 46.4 ± 8.7years. A composite cardiometabolic disease risk score was determined using body mass index, waist circumference, blood pressure and fasting glucose and lipid concentrations. Prediction models were built using a backward stepwise selection approach to explore associations between sleep characteristics and cardiometabolic disease risk factors adjusting for occupational, psychological, and lifestyle covariates.

RESULTS

Average total sleep time was 6.60 ± 0.75 hours, with 51.7% of participants reporting poor sleep quality and 26.2% extending their weekend sleep. Adjusted models showed that lower sleep efficiency (β = -0.25, 95%CI: -0.43; -0.08, P = .006), shorter weekday total sleep time (β = -1.37, 95% CI: -2.41, -0.32; P = .011) and catch-up sleep (β = 0.84, 95%CI: 0.08, 1.60, P = .002) were associated with higher cardiometabolic disease risk scores. Adjusted models also found that shorter average time-in-bed (ß=-2.00, 95%CI: -3.76; -0.18, P = .031), average total sleep time (ß=1.98, 95%CI: -3.70; -0.25, P = .025) and weekday total sleep time (β = -2.13, 95%CI: -3.56; -0.69, P = .025) as well as catch-up sleep (β = 1.67, 95% CI: 0.52; 2.83; P = .012) were all associated with a higher body mass index.

CONCLUSION

Corporate executives who compromise sleep duration during the working week may increase their risk for obesity and future cardiometabolic disease.

Insomnia and stress: the mediating roles of frontoparietal network

Insomnia is a widespread health problem among adults, and it impairs cognitive control and emotional regulation functions. Stress and insomnia are positively correlated, and their vicious cycle has been widely reported. In this study, we explore the neural biomarkers of insomnia from the perspective of whole-brain functional connectivity and investigate the neural mechanisms underlying the association between stress and insomnia. The current study was conducted on a cross-sectional sample (N = 430). First, we investigated the correlation between perceived stress and insomnia. Second, we applied connectome-based predictive modeling (CPM) to determine the neuromarkers of insomnia. Finally, we explored the neural basis underlying the association between perceived stress and insomnia. A significant positive correlation was found between perceived stress and insomnia in the present research. Results of CPM revealed the following as the neural substrates supporting insomnia: the emotion regulation circuit involving repetitive negative thinking and the cognitive control circuit involving attention control. According to further results from mediation analysis, the frontoparietal network supporting cognitive emotion regulation is an important neural mechanism that maintains the correlation between stress and insomnia. The present study offers a profound insight into the alterations of brain activity related to insomnia, and it further investigates the neural underpinnings of the robust association between stress and insomnia. This study also opens new avenues for neural interventions to alleviate stress-related insomnia.

Daily associations between salivary cortisol and electroencephalographic-assessed sleep: a 15-day intensive longitudinal study

STUDY OBJECTIVES

Current evidence suggests that cortisol levels are bi-directionally associated with sleep. However, the daily, naturalistic cortisol-sleep associations remain unclear, as current evidence is mostly cross-sectional. This study tested whether pre-sleep cortisol predicts sleep duration and quality, and whether these sleep parameters predict the following day's diurnal cortisol slope using a 15-day intensive longitudinal design with electroencephalographic measures and saliva sampling.

METHODS

Ninety-five young adults (Mage = 20.48 ± 1.59 years) provided saliva samples at awakening and pre-sleep over 14 consecutive days, providing 2345 samples (85% viable). The Z-Machine Insight + was used to record over 900 nights of total sleep time (TST) and sleep efficiency (SE). Multilevel models tested these data at the between- and within-person levels.

RESULTS

Higher pre-sleep cortisol predicted shorter TST (p < .001) and lower SE (p < .001) at the within-person level. Individuals with shorter average TST (p = .007) or lower average SE (p < .001) had flatter diurnal cortisol slopes, compared to those with longer average TST or higher average SE. Follow-up analyses showed that individuals with shorter average TST (vs. longer average TST) had higher pre-sleep cortisol levels (p = .01).

CONCLUSIONS

Our findings provide evidence that pre-sleep cortisol is associated with sleep duration and quality at the within-individual level. Furthermore, individuals with short or poor sleep had flatter diurnal cortisol slopes. Although the effect sizes are small, these findings show the naturalistic associations between sleep and cortisol in a relatively healthy sample. These findings suggest that sleep maintains the regulation of the stress-response system, which is protective against mental and physical disorders.

Linking Daily Victimization to Daily Affect Among Adolescents: The Mediating Role of Sleep Quality and Disturbance

Bullying victimization is prevalent among adolescents and often linked to emotional problems. Prior studies have been focused on the concurrent or longitudinal associations between bullying victimization and emotional problems, but the daily associations and the underlying mechanisms remain unclear. Implementing daily diary method, the study aimed to examine the links between daily victimization and positive and negative affect as well as the mediating role of sleep quality and disturbance. A total of 265 Chinese adolescents (Mage = 11.65, SD = 0.74; 32.80% females) participated in this study and completed 7-day daily diaries on bullying victimization (traditional and cyber victimization), sleep quality and disturbance, and affect. As hypothesized, at the between-person level, sleep disturbance mediated the relationships between both traditional and cyber victimization and subsequent negative affect. At the within-person level, sleep quality mediated the pathway between traditional victimization and next-day negative affect; furthermore, sleep disturbance mediated the pathway between traditional victimization and positive affect the following day. These findings highlight the mediating roles of sleep quality and sleep disturbance in the relationships between stressful victimizing experiences and emotional problems and also provide novel insights into these associations.

Loneliness, sleep and daily stress: Evidence of direct and indirect effects

This study investigated: i) the effects of loneliness on self-reported sleep outcomes and daily stress/hassles, ii) whether the effects of loneliness on sleep outcomes were mediated through prior-day stress/hassles and iii) if the effects of loneliness on daily stress/hassles were mediated through prior-night sleep measures. Using a 7-day diary design, this study aimed to investigate relationships between loneliness, daily sleep outcomes and daily stress/hassles. Participants (N = 174, Mage 19.95, 86.2% female) completed the UCLA Loneliness Scale once before a 7-day online diary twice per day. Measures of daily stress and hassles were completed before bed and sleep outcomes the following day. Multilevel modelling found higher levels of loneliness were associated with poorer sleep quality, greater pre-sleep arousal, morning tiredness, fewer total hours slept and higher levels of daily stress and hassles across the 7-day study. Loneliness was found also to have indirect effects on sleep quality, pre-sleep arousal and morning tiredness through prior-day daily stress and hassles. In addition, loneliness also had indirect effects on daily stress and hassles through prior night sleep measures. The current findings suggest that interventions aimed at mitigating the effects of loneliness should also incorporate components that target modifiable risk factors such as sleep and stress.

New parents' sleep, movement, health, and well-being across the postpartum period

OBJECTIVE

The aim of this study was to examine changes and the bi-directional relationship in sleep and movement, and health and well-being among new parents and differences by sex.

METHODS

This secondary data analysis included both conditions from a randomized control trial to improve new parents'physical activity [PA] and recruited couples. Parents (n = 181, 117 couples represented 31.5 ± 4.4 years, 51.3% women, 83.3% White) completed questionnaires on regular overnight sleep duration, PA, mental health (perceived stress), physical health (physical quality of life [PQoL]), and well-being (life satisfaction) at 2-, 4-, 6-, and 8-month postpartum. Random-intercept cross-lagged panel models were stratified by sex to examine changes in sleep and PA with health and well-being across time.

RESULTS

Sleep and stress were interrelated at different times for fathers (2 months), and mothers (8 months). Sleep and PQoL improved across time, with mothers reporting less sleep than fathers at 4 and 6 months. PQoL at 4 months was related to MVPA at 6-months. Life satisfaction and PA at 2 months was related to PA at 4 months.

CONCLUSION

Mothers and fathers experienced different sleep and stress trajectories. Mental health improved postpartum with early connections to PA. Supporting the 24-hour movement behavior cycle and mental health across the parenthood transition may benefit couples.

Irregular sleep is linked to poorer mental health: A pooled analysis of eight studies

OBJECTIVES

Greater sleep disturbances on average are a risk factor for impaired mental health. Recent research has shown that more intraindividual variability (i.e., inconsistency) in sleep (hereafter called "sleep intraindividual variability") may also be uniquely related to mental health, even above the influence of mean sleep patterns averaged across days. The current study examined associations between sleep intraindividual variability and symptoms of anxiety, depression, and insomnia across different facets of sleep intraindividual variability (sleep duration, efficiency, and timing) and sleep measurement types (sleep diary and actigraphy).

METHODS

We pooled eight datasets (N = 3053 participants) that assessed repeated measures of sleep diary- and/or actigraphy-determined sleep across multiple days, as well as one-time measures of mental health or sleep disorder symptoms (i.e., anxiety, depression, and insomnia). Multilevel regression analyses were conducted to examine associations between sleep intraindividual variability and mental health or sleep disorder symptoms.

RESULTS

Greater diary- and actigraphy-determined sleep duration intraindividual variability was associated with more depression symptoms (diary: b=0.02, p < .001; actigraphy: b=0.03, p = .006) and more insomnia symptoms (diary: b=0.02, p < .001; actigraphy: b=0.02, p < .001). Greater diary-determined sleep efficiency intraindividual variability was associated with fewer anxiety symptoms (b=-0.23, p = .019) and fewer insomnia symptoms (b=-0.15, p < .001). Greater diary- and actigraphy-determined sleep midpoint intraindividual variability was associated with more insomnia symptoms (diary: b=0.41, p = .044; actigraphy: b=0.66, p = .021).

CONCLUSIONS

More inconsistent sleep duration and sleep timing may be a correlate of poorer mental health. Future experimental work should examine whether stabilizing sleep patterns can improve mental health outcomes.

Examining bi-directional links between loneliness, social connectedness and sleep from a trait and state perspective

Greater loneliness as well as a lack of social connectedness have often been associated with poorer sleep. However, the temporal dynamics and direction of these associations remain unclear. Aim of the current study was to examine bi-directional associations between loneliness/social connectedness and sleep in 48 stress-exposed medical students during their first medical internship, considered a period of heightened stress. We obtained trait-level questionnaire data on loneliness and global sleep completed before and during the internship as well as state-level diary- and wearable-based data on daily changes in social connectedness and sleep collected twice over the period of seven consecutive days, once before and once during the internship. Bi-directional associations among greater loneliness and higher daytime dysfunction on trait-level were identified. In addition, several uni-directional associations between loneliness/social connectedness and sleep were found on trait- and state-level. In sum, findings of this study point at a bi-directional relation among loneliness/social connectedness and sleep, in which variables seem to reciprocally influence each other across longer-term periods as well as on a day-to-day basis.

Stress and Sleep Duration in Immune and Neuroendocrine Patterning. An Analytical Triangulation in ELSA

Background

Proinflammatory and neuroendocrine mediators are implicated in disease aetiopathogenesis. Stress increases concentrations of immune-neuroendocrine biomarkers through a complex network of brain-body signalling pathways. Suboptimal sleep further modulates these processes by altering major effector systems that sensitise the brain to stress. Given the ubiquitous, impactful nature of material deprivation, we tested for a synergistic association of financial stress and suboptimal sleep with these molecular processes.

Methods

With data drawn from the English Longitudinal Study of Ageing (ELSA), associations were tested on 4,940 participants (~66±9.4 years) across four-years (2008-2012). Through analytical triangulation, we tested whether financial stress (>60% insufficient resources) and suboptimal sleep (≤5/≥9 hours) were independently and interactively associated with immune-neuroendocrine profiles, derived from a latent profile analysis (LPA) of C-reactive protein, fibrinogen, white blood cell counts, hair cortisol, and insulin-like growth factor-1.

Results

A three-class LPA model offered the greatest parsimony. After adjustment for genetic predisposition, sociodemographics, lifestyle, and health, financial stress was associated with short-sleep cross-sectionally (RRR=1.45; 95%CI=1.18-1.79; p<0.001) and longitudinally (RRR=1.31; 95%CI=1.02-1.68; p=0.035), and it increased risk of belonging to the high-risk biomarker profile by 42% (95%CI=1.12-1.80; p=0.004). Suboptimal sleep was not related to future risk of high-risk profile membership, nor did it moderate financial stress-biomarker profile associations.

Discussion

Results advance psychoneuroimmunological knowledge by revealing how immune-neuroendocrine markers cluster in older cohorts and respond to financial stress over time. Financial stress associations with short-sleep are supported. The null role of suboptimal sleep, as exposure and mediator, in profile membership, provides valuable insight into the dynamic role of sleep in immune-neuroendocrine processes.

Perceived Stress, but Not Rumination, Mediates the Relationship Between Trait Mindfulness and Sleep Quality in Young Adults

Objective

Poor sleep among young adults is prevalent, yet the mediating variables are largely understudied, and there is limited relevant work utilizing objective sleep measures. The present study investigated the mediating effects of perceived stress and rumination in the relationship between trait mindfulness and subjective and objective sleep quality in young adults.

Methods

A total of 170 healthy adults (aged 18-37, M = 20.8, SD = 2.9) self-reported on trait mindfulness, perceived stress, and rumination. The primary (N = 140) and secondary (N = 30) samples both completed the Pittsburgh Sleep Quality Index (PSQI) to assess subjective sleep quality. The secondary sample (N = 30) additionally provided sleep diaries, as well as wrist-worn actigraphy data for assessing objective sleep quality. A mediation analysis was conducted to assess the effect of trait mindfulness on sleep quality with perceived stress and rumination as mediators.

Results

Trait mindfulness was positively associated with better subjective sleep quality; this was fully mediated by perceived stress, b = -0.08, 95% CI [-.12, -0.06]. Rumination was negatively associated with subjective sleep quality but did not mediate the relationship between trait mindfulness and sleep quality, b = -0.01, 95% CI [-.03, 0.02]. Only trait mindfulness was correlated with diary-based sleep ratings, and none of the measures were associated with actigraphy-based sleep quality.

Conclusion

This study indicates that perceived stress is an important mediator in the relationship between trait mindfulness and subjective sleep quality among young adults, rather than rumination. These findings have implications for mindfulness-based therapeutic approaches to address the high prevalence of sleep disorders among young adults, adding mechanistic detail to the literature.

Postponing sleep after a stressful day: Patterns of stress, bedtime procrastination, and sleep outcomes in a daily diary approach

Sleep problems and stress are common among students and are associated with negative effects on academic performance as well as mental and physical health risks, but studies exploring mediating factors between stress and sleep on a daily basis are scarce. This study aimed to investigate the relationship of daily stress, Bedtime procrastination (BP) (i.e., postponing bedtime without external reasons), and sleep outcomes controlling for trait factors such as self-control. N = 96 students at a German university (M = 22.2 years, SD = 4.0) wore a sleep-tracking wearable (Fitbit Charge HR) for two weeks to assess sleep duration and to calculate the gap between the intended time to go to sleep and the objectively measured time of falling asleep. Stress, intended time to go to sleep, and sleep quality were assessed via daily diaries. Established questionnaires were used to measure trait self-control, trait BP, and smartphone addiction. Multilevel analyses indicated that more stress experienced during the day was associated with more BP (b = 2.32, p = 0.008), shorter sleep duration (b = -3.46, p = 0.003), and lower sleep quality (b = 1.03, p = 0.005) after controlling for several trait factors. The association of daily stress with sleep outcomes (quality and duration) was partly mediated by BP. Our findings indicate that BP might be one factor that contributes to stress-linked decreases in sleep duration and quality. Potential reasons for stress-related later time to fall asleep-like higher physiological arousal or stress-related worries-should be investigated in future studies.

Precision Assessment of Real-World Associations Between Stress and Sleep Duration Using Actigraphy Data Collected Continuously for an Academic Year: Individual-Level Modeling Study

BACKGROUND

Heightened stress and insufficient sleep are common in the transition to college, often co-occur, and have both been linked to negative health outcomes. A challenge concerns disentangling whether perceived stress precedes or succeeds changes in sleep. These day-to-day associations may vary across individuals, but short study periods and group-level analyses in prior research may have obscured person-specific phenotypes.

OBJECTIVE

This study aims to obtain stable estimates of lead-lag associations between perceived stress and objective sleep duration in the individual, unbiased by the group, by developing an individual-level linear model that can leverage intensive longitudinal data while remaining parsimonious.

METHODS

In total, 55 college students (n=6, 11% second-year students and n=49, 89% first-year students) volunteered to provide daily self-reports of perceived stress via a smartphone app and wore an actigraphy wristband for the estimation of daily sleep duration continuously throughout the academic year (median usable daily observations per participant: 178, IQR 65.5). The individual-level linear model, developed in a Bayesian framework, included the predictor and outcome of interest and a covariate for the day of the week to account for weekly patterns. We validated the model on the cohort of second-year students (n=6, used as a pilot sample) by applying it to variables expected to correlate positively within individuals: objective sleep duration and self-reported sleep quality. The model was then applied to the fully independent target sample of first-year students (n=49) for the examination of bidirectional associations between daily stress levels and sleep duration.

RESULTS

Proof-of-concept analyses captured expected associations between objective sleep duration and subjective sleep quality in every pilot participant. Target analyses revealed negative associations between sleep duration and perceived stress in most of the participants (45/49, 92%), but their temporal association varied. Of the 49 participants, 19 (39%) showed a significant association (probability of direction>0.975): 8 (16%) showed elevated stress in the day associated with shorter sleep later that night, 5 (10%) showed shorter sleep associated with elevated stress the next day, and 6 (12%) showed both directions of association. Of note, when analyzed using a group-based multilevel model, individual estimates were systematically attenuated, and some even reversed sign.

CONCLUSIONS

The dynamic interplay of stress and sleep in daily life is likely person specific. Paired with intensive longitudinal data, our individual-level linear model provides a precision framework for the estimation of stable real-world behavioral and psychological dynamics and may support the personalized prioritization of intervention targets for health and well-being.

The moderating role of conscientiousness in the temporal association of stress on sleep

Personality traits have been associated with sleep problems and stress experience. However, their impact on objective sleep and the temporal relationship of stress on sleep has remained elusive. This study examined whether daytime stress predicts sleep the following night, and the moderating role of neuroticism and conscientiousness in this relationship. To introduce stress variability in natural daily stressors, we measured college students (N = 92) during exams (e.g. high academic stress) and at the start of new course period (e.g. low academic stress). Both objective (actigraphy) and subjective sleep, and daily self-reported stress, were measured for 14 days and personality traits once. Reported daily stress was significantly higher in the exam period compared with baseline, suggesting that our natural manipulation did indeed result in variation in stress levels. Intra-individual daily variations in stress were not associated with the following night's sleep timing, duration or fragmentation, implying that more stress during the day did not affect sleep the following night. Higher levels of neuroticism were associated with poorer daily subjective sleep quality and higher stress levels over the complete period. Neuroticism did not moderate the temporal association of stress on sleep. Conscientiousness moderated the association between intra-individual stress and sleep fragmentation, and intra-individual stress and wake-up time. This implied that highly conscientious participants experienced less sleep fragmentation and woke-up earlier after more stressful days. These results suggest an interconnected relationship among stress, sleep and personality. Focusing on one aspect, like handling stress or enhancing sleep quality, might yield positive effects on the rest.

Spatial anxiety contributes to the dizziness-related handicap of adults with peripheral vestibular disease

In subjects with peripheral vestibular disease and controls, we assessed: 1. The relationship between spatial anxiety and perceived stress, and 2. The combined contribution of spatial anxiety, spatial perspective-taking, and individual cofactors to dizziness-related handicap. 309 adults participated in the study (153 with and 156 without peripheral vestibular disease), including patients with bilateral vestibular deficiency, unilateral deficiency (evolution <3 or ≥3 months), Meniere's disease, and Benign Paroxysmal Positional Vertigo. Assessments included: general health, personal habits, spatial anxiety (3-domains), perceived stress, spatial perspective-taking, dizziness-related handicap (3-domains), unsteadiness, sleep quality, motion sickness susceptibility, trait anxiety/depression, state anxiety, depersonalization/derealization. After bivariate analyses, analysis of covariance was performed (p ≤ 0.05). Spatial anxiety was related to unsteadiness and perceived stress, with an inverse relationship with trait anxiety (ANCoVA, adjusted R2 = 0.27-0.30, F = 17.945-20.086, p < 0.00001). Variability on perspective-taking was related to vestibular disease, trait and state anxiety, motion sickness susceptibility, and age (ANCoVA, adjusted R2 = 0.18, F = 5.834, p < 0.00001). All domains of spatial anxiety contributed to the Physical domain of dizziness-related handicap, while the Navigation domain contributed to the Functional domain of handicap. Handicap variability was also related to unsteadiness, spatial perspective-taking, quality of sleep, and trait anxiety/depression (ANCoVA, adjusted R2 = 0.66, F = 39.07, p < 0.00001). Spatial anxiety is related to perceived stress in adults both with and without vestibular disease, subjects with trait anxiety rated lower on spatial anxiety. State anxiety and acute stress could be helpful for recovery after peripheral vestibular lesion. Spatial anxiety and perspective-taking contribute to the Physical and Functional domains of dizziness-related handicap, possibly because it discourages behavior beneficial to adaptation.

Relationship of sleep with diurnal cortisol rhythm considering sleep measurement and cortisol sampling schemes

Information on the relationships between the previous night's sleep and the next-day diurnal cortisol rhythm is inconsistent due to confounding factors such as sleep measurements (trait/state sleep and objective/subjective sleep) and cortisol sampling schemes. Therefore, this study aimed to investigate these relationships, considering the confounding factors. College students (n = 79) wore actigraphy for 3 days to undergo an evaluation of previous night-time sleep objectively and reported their subjective sleep parameters in a sleep diary. In addition, participants provided six salivary cortisol samples daily. Furthermore, six cortisol sampling schemes were created to reflect diurnal cortisol rhythms, and two different methods were used to calculate the index of diurnal cortisol slope (DCS). A multilevel model was created to examine the impact of both trait and state sleep on next-day diurnal cortisol rhythm. The results revealed that higher objective state sleep efficiency and longer objective state total sleep time were associated with a higher cortisol awakening response (CAR). Moreover, higher objective trait sleep efficiency and longer objective trait total sleep time were associated with higher waking cortisol levels and steeper DCS. In addition, a minimum of four saliva samples were required at different time points, including upon waking, 30 min after waking, 1 h after waking, and at bedtime, to explore the relationship of sleep efficiency/total sleep time with waking cortisol, CAR, and DCS. Furthermore, the index of the peak-to-bed slope was appropriately employed to examine the relationship between sleep efficiency and DCS, whereas the wake-to-bed slope was effective for examining the relationship between total sleep time and DCS. In summary, this study clarified the relationship between sleep and next-day diurnal cortisol rhythm and suggested a cost-effective cortisol sampling schedule and calculation methods.

Predicting stress in first-year college students using sleep data from wearable devices

Consumer wearables have been successful at measuring sleep and may be useful in predicting changes in mental health measures such as stress. A key challenge remains in quantifying the relationship between sleep measures associated with physiologic stress and a user's experience of stress. Students from a public university enrolled in the Lived Experiences Measured Using Rings Study (LEMURS) provided continuous biometric data and answered weekly surveys during their first semester of college between October-December 2022. We analyzed weekly associations between estimated sleep measures and perceived stress for participants (N = 525). Through mixed-effects regression models, we identified consistent associations between perceived stress scores and average nightly total sleep time (TST), resting heart rate (RHR), heart rate variability (HRV), and respiratory rate (ARR). These effects persisted after controlling for gender and week of the semester. Specifically, for every additional hour of TST, the odds of experiencing moderate-to-high stress decreased by 0.617 or by 38.3% (p<0.01). For each 1 beat per minute increase in RHR, the odds of experiencing moderate-to-high stress increased by 1.036 or by 3.6% (p<0.01). For each 1 millisecond increase in HRV, the odds of experiencing moderate-to-high stress decreased by 0.988 or by 1.2% (p<0.05). For each additional breath per minute increase in ARR, the odds of experiencing moderate-to-high stress increased by 1.230 or by 23.0% (p<0.01). Consistent with previous research, participants who did not identify as male (i.e., female, nonbinary, and transgender participants) had significantly higher self-reported stress throughout the study. The week of the semester was also a significant predictor of stress. Sleep data from wearable devices may help us understand and to better predict stress, a strong signal of the ongoing mental health epidemic among college students.

Sleep-Related Predictors of Risk for Alcohol Use and Related Problems in Adolescents and Young Adults

PURPOSE

Growing evidence supports sleep and circadian rhythms as influencing alcohol use and the course of alcohol use disorder (AUD). Studying sleep/circadian-alcohol associations during adolescence and young adulthood may be valuable for identifying sleep/circadian-related approaches to preventing and/or treating AUD. This paper reviews current evidence for prospective associations between sleep/circadian factors and alcohol involvement during adolescence and young adulthood with an emphasis on the effects of sleep/circadian factors on alcohol use.

SEARCH METHODS

The authors conducted a literature search in PsycInfo, PubMed, and Web of Science using the search terms "sleep" and "alcohol" paired with "adolescent" or "adolescence" or "young adult" or "emerging adult," focusing on the title/abstract fields, and restricting to English-language articles. Next, the search was narrowed to articles with a prospective/longitudinal or experimental design, a sleep-related measure as a predictor, an alcohol-related measure as an outcome, and confirming a primarily adolescent and/or young adult sample. This step was completed by a joint review of candidate article abstracts by two of the authors.

SEARCH RESULTS

The initial search resulted in 720 articles. After review of the abstracts, the list was narrowed to 27 articles reporting on observational longitudinal studies and three articles reporting on intervention trials. Noted for potential inclusion were 35 additional articles that reported on studies with alcohol-related predictors and sleep-related outcomes, and/or reported on candidate moderators or mediators of sleep-alcohol associations. Additional articles were identified via review of relevant article reference lists and prior exposure based on the authors' previous work in this area.

DISCUSSION AND CONCLUSIONS

Overall, the review supports a range of sleep/circadian characteristics during adolescence and young adulthood predicting the development of alcohol use and/or alcohol-related problems. Although sleep treatment studies in adolescents and young adults engaging in regular and/or heavy drinking show that sleep can be improved in those individuals, as well as potentially reducing alcohol craving and alcohol-related consequences, no studies in any age group have yet demonstrated that improving sleep reduces drinking behavior. Notable limitations include relatively few longitudinal studies and only two experimental studies, insufficient consideration of different assessment timescales (e.g., day-to-day vs. years), insufficient consideration of the multidimensional nature of sleep, a paucity of objective measures of sleep and circadian rhythms, and insufficient consideration of how demographic variables may influence sleep/circadian-alcohol associations. Examining such moderators, particularly those related to minoritized identities, as well as further investigation of putative mechanistic pathways linking sleep/circadian characteristics to alcohol outcomes, are important next steps.

Associations of perceived stress with loneliness and depressive symptoms: the mediating role of sleep quality

BACKGROUND

Whether perceived stress is associated with loneliness and depressive symptoms in general adults, and to what extent sleep quality mediates the associations, remains unknown. The aim of this study was to estimate the associations of perceived stress with loneliness and depressive symptoms, and the mediating role of sleep quality in these associations.

METHODS

Cross-sectional data on 734 participants (aged 18-87 years) were analyzed. Perceived stress was assessed using the 10-item Perceived Stress Scale (PSS-10; range 0-40). Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI; range 0-21). Loneliness was assessed using the three-item short form of the Revised University of California, Los Angeles (UCLA) loneliness scale (range 3-9). Depressive symptoms were assessed using the 10-item Center for Epidemiologic Studies Depression (CESD-10) Scale (range 0-30). General linear regression models, multivariable logistic regression models, and formal mediation analysis were performed.

RESULTS

After adjustment for age and sex, we found that with each 1-point increment in the perceived stress score, both the loneliness score (β = 0.07; 95% confidence interval [CI]: 0.06, 0.08) and depression score (β = 0.45; 95% CI: 0.40, 0.49) increased significantly. Robust results were observed when adjusting for more confounders. Furthermore, sleep quality mediated 5.3% (95% CI: 1.3%, 10.0%; P = 0.014) and 9.7% (95% CI: 6.2%, 14.0%; P < 0.001) of the associations of perceived stress score with loneliness score and depression score, respectively.

CONCLUSIONS

In general Chinese adults, perceived stress was positively associated with loneliness and depressive symptoms, and sleep quality partially mediated these associations. The findings reveal a potential pathway from perceived stress to mental health through sleep behaviors, and highlight the importance of implementing sleep intervention programs for promoting mental health among those who feel highly stressed.

Perfectionism, perceived stress, and presleep arousal in insomnia: effects on sleep in a daily life study

STUDY OBJECTIVES

Perfectionism is considered a predisposing and maintaining factor for insomnia disorder. However, previous studies were predominantly based on retrospective self-reports of sleep and have yielded mixed results. Here, we investigated associations between perfectionism, daily stress levels, pre-sleep arousal, and actigraphic and sleep diary-derived sleep in insomnia using an experience sampling design.

METHODS

Individuals with insomnia (n = 63) reported their trait perfectionism levels and completed assessments on seven consecutive days. Momentary stress levels were reported on mobile phones at three semirandom time points each day. Presleep arousal levels were rated each morning for the previous night. Sleep onset latency, total sleep time, wake after sleep onset, and sleep efficiency were assessed prospectively using actigraphic watches and sleep diaries.

RESULTS

Perfectionism dimensions and daily stress levels did not predict self-reported or actigraphic sleep parameters. Higher levels of somatic and cognitive presleep arousal were robustly associated with indicators of poorer same-night sleep. The concern over mistakes and doubts dimension of perfectionism interacted with cognitive presleep arousal in predicting self-reported sleep parameters. In the presence of higher presleep arousal, participants with high concern over mistakes and doubts experienced shorter self-reported total sleep time and lower sleep efficiency (both Ps < .01) than on days with lower cognitive arousal.

CONCLUSIONS

Taken together, our results did not indicate an impact of heightened perfectionism levels on sleep in individuals with insomnia, based on prospective sleep assessments. However, our findings provide further evidence for the role of somatic and cognitive presleep arousal, potentially interacting with perfectionism, in the perpetuation of insomnia symptoms.

CITATION

Küskens A, Stricker J, Hertrampf LS, Pietrowsky R, Gieselmann A. Perfectionism, perceived stress, and presleep arousal in insomnia: effects on sleep in a daily life study. J Clin Sleep Med. 2024;20(3):433-443.

Perceived Parenting Stress Is Related to Cardiac Flexibility in Mothers: Data from the NorBaby Study

Heart rate variability (HRV) is an indicator of autonomic nervous system activity, and high levels of stress and/or depressive symptoms may reduce HRV. Here, we assessed whether (a) parental stress affected HRV in mothers during the perinatal period and whether this is mediated by bonding and (b) whether antenatal maternal mental states, specifically repetitive negative thinking, depressive symptoms, and pregnancy-related anxiety, have an impact on infant HRV, and lastly, we investigated (c) the relationship between maternal HRV and infant HRV. Data are from the Northern Babies Longitudinal Study (NorBaby). In 111 parent-infant pairs, cardiac data were collected 6 months after birth. In the antenatal period, we used the Pregnancy-Related Anxiety Questionnaire-Revised, the Edinburgh Postnatal Depression Scale, and the Perseverative Thinking Questionnaire; in the postnatal period, we used the Parenting Stress Index and the Maternal Postnatal Attachment Scale. Higher levels of perceived parenting stress but not depressive symptoms were associated with lower HRV in mothers (τ = -0.146), and this relationship was not mediated by maternal bonding. Antenatal maternal mental states were not associated with infant HRV. There was no significant correlation between maternal HRV and infant HRV. Our observational data suggest that perceived stress reduces cardiac flexibility. Future studies should measure HRV and parenting stress repeatedly during the perinatal period.

Various types of stress and greater use of disengagement coping are associated with worse sleep disturbance in oncology patients undergoing chemotherapy

Various types of stress and the choice of coping strategies may be risk factors for higher levels of sleep disturbance in oncology patients. Purposes were to evaluate for differences in global, cancer-specific, and cumulative life stress, as well as resilience and the use of coping strategies among three subgroups of patients with distinct sleep disturbance profiles (i.e., Low, High, Very High). Oncology outpatients (n = 1331) completed measures of global (Perceived Stress Scale), cancer-specific (Impact of Event Scale-Revised), and cumulative life (Life Stressor Checklist-Revised) stress, resilience (Connor-Davidson Resilience Scale) and coping (Brief Cope) prior to their second or third cycle of chemotherapy. Sleep disturbance was assessed six times over two chemotherapy cycles. Differences were evaluated using parametric and non-parametric tests. All stress measures showed a dose response effect (i.e., as the sleep disturbance profile worsened, levels of all types of stress increased). Compared to Low class, the other two classes reported higher levels of global perceived stress and higher occurrence rates and effect from previous stressful life events. Impact of Event Scale-Revised scores for the Very High class indicated post-traumatic symptomatology. Patients in High and Very High classes had resilience scores below the normative score for the United States population and used a higher number of disengagement coping strategies. Our findings suggest that very high levels of sleep disturbance are associated with higher levels of various types of stress, lower levels of resilience, and higher use of disengagement coping strategies. Clinicians need to perform routine assessments and implement symptom management interventions to reduce stress and encourage the use of engagement coping strategies.

Weight bias internalization is positively associated with insomnia symptom severity in young women with disordered eating

OBJECTIVE

Social stigma has been associated with disparities in sleep heath; however, one type of stigma that has been less evaluated is weight bias internalization. Previous studies have shown inconsistent results linking weight bias internalization and sleep problems and few have examined associations with insomnia.

METHODS

Women with disordered eating (N = 173, Mage=20.22, SD=1.70, range=18-25) completed questionnaires measuring insomnia symptoms, weight bias internalization, alcohol use, and dysphoria. Linear regression tested associations between weight bias internalization and insomnia symptom severity, after adjusting for demographic variables, alcohol use, and dysphoria.

RESULTS

Weight bias internalization, alcohol use, and dysphoria were significantly positively associated with insomnia symptom severity above-and-beyond demographic variables.

CONCLUSIONS

Although effect sizes were small, weight bias internalization was associated with greater insomnia symptom severity. Results add to the growing literature examining the associations of stigma with sleep health.

Exploring the short-term influence of a proprietary oil extract of black cumin (Nigella sativa) on non-restorative sleep: a randomized, double-blinded, placebo-controlled actigraphy study

Background

Nigella sativa (black cumin, or black seed) is popularly known as the seed of blessings in the Arab system of medicine. Though not widely recommended for sleep, a unique proprietary black cumin extract (BlaQmax®/ThymoDream™; BCO-5) has been shown to be helpful in the management of stress and sleep issues.

Methods

This randomized, double-blind, placebo-controlled trial aimed to investigate the efficacy of BCO-5 on the sleep quality of volunteers characterized with a self-reported non-restorative sleep disorder. Healthy male and female participants (n = 70), aged 18-65 years (BMI 22-28 Kg/m2) were randomized to either placebo or BCO-5 (n = 35/group). Both interventions were supplemented at 200 mg/day for seven days. Actigraphy and a validated restorative sleep questionnaire (RSQ-W) were used to monitor the influence of BCO-5 on sleep.

Results

Compared to placebo, BCO-5 significantly improved sleep quality, as evidenced by both intra-group and inter-group analyses of the actigraphy data. The relative improvements observed were sleep efficiency (7.8%, p < 0.001), total sleep time (19.1%, p < 0.001), sleep onset latency (35.4%; p < 0.001), and wake-after-sleep-onset (22.5%; p < 0.001) compared with placebo. BCO-5 also improved sleep by 75.3% compared to baseline (p < 0.001) and by 68.9% compared to placebo (p < 0.001), when monitored by RSQ-W. BCO-5 was well-tolerated with no reports of side effects or toxicity.

Conclusion

BCO-5 significantly improved non-restorative sleep in seven days, indicating its potential role as a natural sleep aid.

Sleep and daytime functioning in children with tourette syndrome: A two-week case-control study with actigraphy and cognitive assessments

There is increasing recognition of the high prevalence of sleep issues in children with Tourette syndrome (TS), a condition characterised by motor and vocal tics. Overnight polysomnography (PSG) has been the primary mode of sleep assessment in the TS literature, despite the extensive use of actigraphy in other neurodevelopmental populations. As a result, there are existing research gaps surrounding day-to-day variability of sleep in TS and links to daytime functioning. This study adopts a naturalistic, intensive longitudinal design to examine sleep in children with TS while considering potential links to tic severity and daytime functioning. Participants were 34 children aged between 8 and 12 years (12 with TS, 22 neurotypical controls). Wrist actigraphs tracked sleep-wake cycles across two weeks and a battery of scales and cognitive assessments measured sleep disturbances and daytime functioning. Mixed models using N = 476 nights of actigraphy data found that relative to controls, children with TS had significantly increased time in bed, increased sleep onset latency, reduced sleep efficiency, lower subjective sleep quality, but comparable actual sleep time. Higher self-report tic severity at bedtime did not predict increased sleep onset latency. In the sleep disturbance scale, 83.33 % of children with TS met the clinical cut-off for a sleep disorder. Parent-report emotional, behavioural, and executive difficulties were greater in the TS group relative to controls, but performance on cognitive tasks was comparable between groups. Together, findings highlight sleep disturbances as an important clinical factor to consider in the management of TS, though further research is required to substantiate findings in larger-scale studies. This study demonstrates the feasibility of assessing sleep via actigraphy in children with TS, supporting more widespread use in the future.

Assessing 'readiness' by tracking fluctuations in daily sleep duration and their effects on daily mood, motivation, and sleepiness

STUDY OBJECTIVES

Consumer sleep trackers issue daily guidance on 'readiness' without clear empirical basis. We investigated how self-rated mood, motivation, and sleepiness (MMS) levels are affected by daily fluctuations in sleep duration, timing, and efficiency and overall sleep regularity. We also determined how temporally specific these associations are.

METHODS

119 healthy university students (64 female, mean age = 22.54 ± 1.74 years) wore a wearable sleep tracker and undertook twice-daily smartphone-delivered ecological momentary assessment of mood, motivation, and sleepiness at post-wake and pre-bedtime timings for 2-6 weeks. Naps and their duration were reported daily. Nocturnal sleep on 2471 nights were examined using multilevel models to uncover within-subject and between-subject associations between sleep duration, timing, efficiency, and nap duration on following day MMS ratings. Time-lagged analyses examined the temporal specificity of these associations. Linear regression models investigated associations between MMS ratings and sleep variability, controlling for sleep duration.

RESULTS

Nocturnal sleep durations were short (6.03 ± 0.71 h), and bedtimes were late (1:42AM ± 1:05). Within-subjects, nocturnal sleep longer than a person's average was associated with better mood, higher motivation, and lower sleepiness after waking. Effects of such longer sleep duration lingered for mood and sleepiness till the pre-bedtime window (all Ps < .005) but did not extend to the next day. Between-subjects, higher intraindividual sleep variability, but not sleep duration, was associated with poorer mood and lower motivation after waking. Longer average sleep duration was associated with less sleepiness after waking and lower motivation pre-bedtime (all Ps < .05). Longer naps reduced post-nap sleepiness and improved mood. Controlling for nocturnal sleep duration, longer naps also associated with lower post-waking sleepiness on the following day.

CONCLUSIONS

Positive connections between nocturnal sleep and nap duration with MMS are temporally circumscribed, lending credence to the construction of sleep-based, daily 'readiness' scores. Higher sleep duration variability lowers an individual's post waking mood and motivation.

CLINICAL TRIAL ID

ClinicalTrials.gov NCT04880629.

Effects of childhood trauma on sleep quality and stress-related variables in adulthood: evidence from two multilevel studies

Childhood trauma has been found to have serious negative consequences for mental and physical health. However, the precise mechanisms through which trauma influences health outcomes are unclear. Childhood trauma-related disruptions to sleep in adulthood represent an important potential mechanism. Two 7-day multilevel studies investigated the effects of childhood trauma on daily sleep outcomes and stress-related variables and whether the effects of trauma on sleep outcomes were mediated through these stress-related variables (or vice versa). Participants completed the Childhood Trauma Questionnaire before a 7-day online daily diary study. Measures of daily stress, perseverative cognition, and sleep were completed daily. Multi-level modelling found that higher levels of childhood neglect were associated with poorer daily sleep quality, shorter sleep duration, longer sleep onset latency, and higher daily stress and rumination levels. Higher childhood abuse was associated with shorter sleep duration, greater morning tiredness, and higher levels of daily stress, rumination, and worry. Childhood trauma was found also to have bidirectional, indirect effects on sleep quality and morning tiredness through daily stress-related variables. The current findings suggest that interventions aimed at mitigating the negative effects of childhood trauma should also incorporate components that target modifiable risk factors, such as sleep, stress, worry, and rumination.

Longitudinal interactions between residual symptoms and physiological stress in the remitted symptom network structure of depression

Residual symptoms and stress are amongst the most reliable predictors of relapse in remitted depression. Standard methodologies often preclude continuous stress sampling or the evaluation of complex symptom interactions. This limits knowledge acquisition relative to the day-to-day interactions between residual symptoms and stress. The study aims to explore the interactions between physiological stress and residual symptoms network structure in remitted depression. Twenty-two individuals remitted from depression completed baseline, daily diary (DD), and post-DD assessments. Self-reported stress and residual symptoms were measured at baseline and post-DD. Daily diaries required participants to use a wearable electrodermal activity (EDA) device during waking hours and complete residual symptom measures twice daily for 3-weeks. Two-step multilevel vector auto-regression models were used to estimate contemporaneous and dynamic networks. Depressed mood and concentration problems were central across networks. Skin conductance responses (SCRs), suicide, appetite, and sleep problems were central in the temporal and energy loss in the contemporaneous network. Increased SCRs predicted decreased energy loss. Residual symptoms and stress showed bi-directional interactions. Overall, depressed mood and concentration problems were consistently central, thus potentially important intervention targets. Non-obtrusive bio-signal measures should be used to provide the clinical evidence-base for modelling the interactions between depressive residual symptoms and stress. Practical implications are discussed throughout related to focusing on symptom-specific interactions in clinical practice, simultaneously reducing residual symptom and stress occurrences, EDA as pioneering signal for stress detection, and the central role of specific residual symptoms in remitted depression.

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.

Evaluating User Compliance in Mobile Health Apps: Insights from a 90-Day Study Using a Digital Sleep Diary

Sleep diaries are the gold standard for subjective assessment of sleep variables in clinical practice. Digitization of sleep diaries is needed, as paper versions are prone to human error, memory bias, and difficulties monitoring compliance.

METHODS

45 healthy eligible participants (Mage = 50.3 years, range 23-74, 56% female) were asked to use a sleep diary mobile app for 90 consecutive days. Univariate and bivariate analysis was used for group comparison and linear regression for analyzing reporting trends and compliance over time.

RESULTS

Overall compliance was high in the first two study months but tended to decrease over time (p < 0.001). Morning and evening diary entries were highly correlated (r = 0.932, p < 0.001) and participants significantly answered on average 4.1 days (95% CI [1.7, 6.6]) more often in the morning (M = 60.2, sd = 22.1) than evening ((M = 56.1, sd = 22.2), p < 0.001).

CONCLUSION

Using a daily diary assessment in a longitudinal sleep study with a sleep diary delivered through a mobile application was feasible, and compliance in this study was satisfactory.

Daily Sleep-Stress Reactivity and Functional Impairment in World Trade Center Responders

BACKGROUND

How sleep is impacted by stress ("sleep reactivity to stress") and how stress is impacted by sleep ("stress reactivity to sleep") are trait-like characteristics of individuals that predict depression, anxiety, and insomnia. However, pathways between reactivity and functional impairment (e.g., impairment in social relationships and interpersonal functioning) have not been explored, which may be a critical pathway in understanding the link between reactivity and the development of psychological disorders.

PURPOSE

We examined associations between reactivity and changes in functional impairment among a cohort of 9/11 World Trade Center responders.

METHODS

Data from 452 responders (Mage = 55.22 years; 89.4% male) were collected between 2014 and 2016. Four baseline sleep and stress reactivity indices (i.e., sleep duration and efficiency reactivity to stress; stress reactivity to sleep duration and efficiency) were calculated from 14 days of sleep and stress data using random slopes from multilevel models. Functional impairment was assessed approximately 1 year and 2 years after baseline via semi-structured interviews. Latent change score analyses examined associations between baseline reactivity indices and changes in functional impairment.

RESULTS

Greater baseline sleep efficiency reactivity to stress was associated with decreases in functioning (β = -0.05, p = .039). In addition, greater stress reactivity to sleep duration (β = -0.08, p = .017) and sleep efficiency (β = -0.22, p < .001) was associated with lower functioning at timepoint one.

CONCLUSION

People who are more reactive to daily fluctuations in stress and sleep have poorer interpersonal relationships and social functioning. Identifying individuals with high reactivity who could benefit from preventative treatment may foster better social integration.

Relationship between sleep disturbance and burnout among Chinese urban teachers: Moderating roles of resilience

BACKGROUND

Sleep disturbance and burnout are prevalent among primary and secondary school teachers. Nevertheless, little is known about the relationship between sleep disturbance and burnout, and the mechanisms connecting this link. Our study aimed to explore the relationship between sleep disturbance and burnout among urban teachers, as well as to investigate this influencing mechanism further with resilience as a moderator.

METHODS

14,218 primary and secondary school teachers provided valid data. We assessed demographic information, sleep disturbance, burnout, and resilience. Multivariable logistic regression, Spearman correlation, and moderation analyses were used to evaluate the relationship between sleep disturbance and burnout and the moderating role of resilience.

RESULTS

Of the participants, the prevalence of sleep disturbance and sleep deprivation among teachers was 20.0% and 31.7%, respectively. Additionally, 58.4% of teachers reported moderate or severe burnout, and 15.3% had both sleep disturbance and burnout. Sleep disturbance was significant and positively related to burnout. Resilience was found to moderate the association between sleep disturbance and burnout.

CONCLUSIONS

These findings suggested strong associations between sleep disturbance and burnout. Interventions in improving resilience may protect teachers with sleep disturbance from burnout.

Examining Daily Associations Among Sleep, Stress, and Blood Pressure Across Adulthood

BACKGROUND

Sleep can have consequential effects on people's health and well-being, and these effects may vary among younger and older adults.

PURPOSE

The goal of the present study was to investigate how sleep relates to physiologic and stress responses in daily life across adulthood.

METHODS

We used an Ecological Momentary Assessment method in a large sample of participants (N = 4,359; Mage = 46.75, SD = 12.39; 69.30% male, 29.85% female) who completed morning sleep diaries, reported subjective stress, and recorded their heart rate and blood pressure for 21 days. Sleep was assessed with self-reports of duration, efficiency, and quality.

RESULTS

Using multilevel modeling, between-person analyses showed that sleep duration, efficiency, and quality were negatively related to morning heart rate and stress, such that people who slept longer, more efficiently, or better experienced lower heart rate and stress compared to those who slept shorter, less efficiently, or worse. Within-person analyses showed that sleep duration, efficiency, and quality predicted morning heart rate, blood pressure (though less consistently), and stress. That is, people experienced lower heart, blood pressure, and stress following nights when they slept longer, more efficiently, or better than they typically did. These within-person relationships were moderated by age, such that the effects of better and longer sleep on lower morning heart rate, blood pressure, and stress were stronger among younger than older adults.

CONCLUSION

These findings suggest that daily variations in sleep show immediate associations with stress and physiologic responses, but these daily variations have a stronger relationship among younger compared to older adults.

Coping strategies predict daily emotional reactivity to stress: An ecological momentary assessment study

BACKGROUND

Emotional reactivity predicts poor health and psychopathology. Despite its theoretical importance, little research has tested whether coping predicts emotional reactivity to stressors. We analyse three studies to test this hypothesis for negative (NA) and positive affect (PA) reactivity to daily stressors.

METHODS

422 Participants (72.5 % females, M_age = 22.79 ± 5.36) came from three longitudinal, ecological momentary assessment (EMA) studies across 7-15 days (ACES N = 190; DESTRESS N = 134; SHS N = 98). Coping was measured at baseline. NA, PA, and daily stressors were assessed via EMA. Mixed effects linear models tested whether coping predicted NA and PA reactivity, defined as their slope on within- and between-person daily stressors.

RESULTS

Behavioural disengagement and mental disengagement coping predicted greater within-person NA reactivity across all studies (all p < .01, all f² = 0.01). Denial coping predicted greater within-person NA reactivity in ACES and DESTRESS (both p < .01, f² from 0.02 to 0.03) and between-person in ACES and SHS (both p < .01, f² from 0.02 to 0.03). For approach-oriented coping, only active planning coping predicted lower within-person NA reactivity and only in DESTRESS (p < .01, f² = 0.02). Coping did not predict PA reactivity (all p > .05).

LIMITATIONS

Our findings cannot be generalised to children or older adults. Emotional reactivity to daily stressors may differ from severe or traumatic stressors. Although data were longitudinal, the observational design precludes establishing causality.

CONCLUSIONS

Avoidance-oriented coping strategies predicted greater NA reactivity to daily stressors with small effect sizes. Few and inconsistent results emerged for approach-oriented coping and PA reactivity. Clinically, our results suggest that reducing reliance on avoidance-oriented coping may reduce NA reactivity to daily stressors.

Beyond Stress: Altered Sleep-Wake Patterns are a Key Behavioral Risk Factor for Acute Insomnia During Times of Crisis

BACKGROUND

Stress is a common precipitant of acute insomnia; however, reducing stress during times of crisis is challenging. This study aimed to determine which modifiable factors, beyond stress, were associated with acute insomnia during a major crisis, the COVID-19 pandemic.

PARTICIPANTS/METHODS

A global online survey assessed sleep/circadian, stress, mental health, and lifestyle factors between April-May 2020. Logistic regression models analyzed data from 1319 participants (578 acute insomnia, 731 good sleepers), adjusted for demographic differences.

RESULTS

Perceived stress was a significant predictor of acute insomnia during the pandemic (OR 1.23, 95% CI1.19-1.27). After adjusting for stress, individuals who altered their sleep-wake patterns (OR 3.36, CI 2.00-5.67) or increased technology use before bed (OR 3.13, CI 1.13-8.65) were at increased risk of acute insomnia. Other sleep factors associated with acute insomnia included changes in dreams/nightmares (OR 2.08, CI 1.32-3.27), increased sleep effort (OR 1.99, CI1.71-2.31) and cognitive pre-sleep arousal (OR 1.18, CI 1.11-1.24). For pandemic factors, worry about contracting COVID-19 (OR 3.08, CI 1.18-8.07) and stringent government COVID-19 restrictions (OR 1.12, CI =1.07-1.18) were associated with acute insomnia. Anxiety (OR 1.02, CI 1.01-1.05) and depressive (OR 1.29, CI 1.22-1.37) symptoms were also risk factors. A final hierarchical regression model revealed that after accounting for stress, altered sleep-wake patterns were a key behavioral predictor of acute insomnia (OR 2.60, CI 1.68-5.81).

CONCLUSION

Beyond stress, altered sleep-wake patterns are a key risk factor for acute insomnia. Modifiable behaviors such as maintaining regular sleep-wake patterns appear vital for sleeping well in times of crisis.

Investigating sleep, stress, and mood dynamics via temporal network analysis

OBJECTIVE/BACKGROUND

Prior research has emphasized the bidirectional relationships between sleep, stress, and affective states, such as depression. Given the inherent variability and fluctuations associated with sleep, assessing how sleep and affective variables function within a dynamic system may help further uncover possible causes and consequences of sleep disturbances, as well as find candidate targets for intervention. To this end, we examined dynamic relationships between self-reported stress, depressed mood, and clinically-relevant sleep parameters via temporal network analysis.

METHODS

Participants were 401 nurses (92% female, 78% White, Mage = 39.47 years) who completed 14 days of sleep diaries incorporating self-reported stress and depression, as well as total sleep time, sleep efficiency, sleep onset latency, and wake after sleep onset.

RESULTS AND CONCLUSIONS

Overall, total sleep time emerged as a highly influential variable in the context of "outstrength centrality," meaning total sleep time had numerous outward connections with other variables (e.g., stress and sleep efficiency). The high outstrength centrality of total sleep time suggests this variable is a source of activation within this dynamic system. Conversely, stress showed high "instrength centrality," suggesting this variable was highly impacted by other variables in the system, such as depressed mood and sleep efficiency. These findings emphasize the importance of assessing unfolding sleep processes within a naturalistic setting, and implicate the role of total sleep time in fueling depressed mood and stress. Discussion emphasizes implications of these results for understanding the connections between sleep, stress, and depression as well as clinical relevance of these findings.

Food insecurity and insomnia-related symptoms among adults from low- and middle-income countries

Little is known about the relationship between food insecurity and sleep problems in low- and middle-income countries, while the mediators of this association are largely unknown. Therefore, we investigated the association between food insecurity and insomnia-related symptoms in six low- and middle-income countries (i.e., China, Ghana, India, Mexico, Russia, South Africa), and the potential mediators of this relationship. Cross-sectional, nationally representative data from the Study on Global AGEing and Adult Health (2007-2010) were analysed. Past 12-month food insecurity was assessed with two questions on the frequency of eating less, and on hunger owing to a lack of food. Insomnia-related symptoms referred to severe or extreme sleep problems in the past 30 days. Multivariable logistic regression and mediation analysis were conducted. Data on 42,489 adults aged ≥18 years were analysed (mean [standard deviation] age 43.8 [14.4] years; 50.1% females). The prevalence of any food insecurity and insomnia-related symptoms was 11.9% and 4.4%, respectively. After adjustment, compared with no food insecurity, moderate (odds ratio = 1.53, 95% confidence interval = 1.11-2.10) and severe food insecurity (odds ratio = 2.35, 95% confidence interval = 1.56-3.55) were significantly associated with insomnia-related symptoms. Anxiety, perceived stress, and depression mediated 27.7%, 13.5%, and 12.5% of the relationship between any food insecurity and insomnia-related symptoms, respectively (total percentage = 43.3%). Food insecurity was positively associated with insomnia-related symptoms in adults from six low- and middle-income countries. Anxiety, perceived stress, and depression explained a substantial proportion of this relationship. Addressing food insecurity itself or the identified potential mediators among people with food insecurity may lead to a reduction in sleep problems among adults in low- and middle-income countries, pending confirmation with longitudinal studies.

Daily reactivity to stress and sleep disturbances: unique risk factors for insomnia

STUDY OBJECTIVES

To naturalistically measure sleep disturbances following stress exposure (i.e. sleep reactivity) and stress responses following sleep disturbances (i.e. stress reactivity) at the daily level and prospectively examine these reactivity measures as individual risk factors for insomnia.

METHODS

The study assessed 392 nurses' sleep and stress for 14 days using daily diaries and actigraphy. Self-reported insomnia symptoms were assessed at the end of the 14 days, as well as 6 and 11 months later.

RESULTS

In multilevel modeling, while negative fixed effects indicated that shorter total sleep time (TST) and lower sleep efficiency led to greater stress and vice versa, significant random effects indicated individual variability in sleep reactivity and stress reactivity. In latent score change modeling, greater sleep reactivity (lower diary-determined sleep efficiency following greater stress) and greater stress reactivity (greater stress following shorter diary-determined TST) at baseline were associated with greater insomnia symptoms at 11 months (b = 10.34, p = .026; b = 7.83, p = .03). Sleep reactivity and stress reactivity also interacted to predict insomnia symptoms, such that sleep reactivity was significantly associated with insomnia symptoms for those with high (+1 SD) stress reactivity (b = 17.23, p = .001), but not for those with low (-1 SD) stress reactivity (b = 5.16, p = .315).

CONCLUSIONS

Baseline stress reactivity and sleep reactivity independently as well as jointly predict greater insomnia symptoms 11 months later. The findings delineate processes underlying the stress-diathesis model of insomnia and highlight the utility of longitudinal and naturalistic measures of sleep and stress reactivity.

The association of stress and work hours with sleep duration and insomnia symptoms among U.S.-born and Foreign-born Black adults

OBJECTIVE

To examine associations between stress and work hours with sleep duration and insomnia symptoms among U.S.-born and Foreign-born Black adults.

DESIGN

A cross-sectional analysis of the National Health Interview Survey.

PARTICIPANTS

Black adults (N = 16,315) with a mean age of 40 ± 0.1 years, mostly women (52.7%), college graduates (40.7%), and U.S.-born (82.5%).

MEASUREMENTS

Participants self-reported sleep duration, insomnia symptoms, frequent stress (yes/no), and work hours in the prior week (1-39 hours, 40 hours, ≥41 hours). Poisson regression with robust variance was used to test associations overall and by nativity.

RESULTS

Working ≥41 hours, frequent stress, and short sleep duration (<7 hours) were reported by 22%, 24.9%, and 43% of participants, respectively. U.S.-born and Foreign-born Black adults who reported frequent stress and working ≥41 hours vs. 40 hours had 60% and 19% higher prevalence of short sleep duration (adjusted prevalence ratio [aPR] = 1.60, 95% confidence interval [CI]: 1.47, 1.74 and aPR = 1.19, 95% CI: 1.12, 1.25, respectively). Foreign-born Black adults who worked 1-39 hours vs. 40 hours, had higher prevalence of short sleep duration, aPR = 1.18, 95% CI: 1.01, 1.37. U.S.-born Black adults who worked ≥41 hours vs. 40 hours had higher prevalence of insomnia symptoms (trouble falling asleep: aPR = 1.33 [95% CI: 1.13, 1.56], trouble staying asleep: aPR = 1.33 [95% CI: 1.16, 1.53]).

CONCLUSION

Frequent stress and working ≥41 hours are likely salient determinants of sleep health for U.S. and Foreign-born Black individuals. Further, less work hours (Foreign-born) while longer work hours (U.S.-born) were associated with short sleep duration. Stress and work hours may be factors for sleep health interventions among Black adults.

Improving Sleep Among Teachers: an Implementation-Intention Intervention

BACKGROUND

Insufficient sleep is common among teachers and is associated with diverse health risks. This study aimed to predict intention and sleep duration by applying the Theory of Planned Behavior (TPB) and to examine the effectiveness of an implementation-intention intervention to improve sleep duration and quality.

METHOD

Sixty-nine teachers (M = 36.8 years, SD = 10.4) were assigned to an active control group (CG) or intervention group (IG). At baseline, TPB variables were assessed and participants of the IG received instructions to develop implementation intentions to reach the goal of sleeping 8 h on average. During a 3-week intervention period, all participants wore an activity tracker (Fitbit Charge HR) to measure sleep duration and kept diaries to assess sleep quality, physical activity, and stress. After 1 month, a 1-week follow-up, including a booster for the IG, was conducted.

RESULTS

Forty-two percent of variance in sleep duration were explained by control variables, past behavior, perceived behavioral control, and intention. Mixed ANOVAS with baseline covariates found a large main effect with longer sleep duration in the IG. A time x group interaction suggested that only the IG slept significantly longer in the follow-up period compared to the intervention period. For sleep quality, a medium-sized main effect for study group was found and a time x group interaction indicated higher sleep quality in the IG for week 3 and the follow-up.

CONCLUSION

The TPB was effective in predicting sleep intention and duration. Implementation intentions accompanied by daily monitoring and a booster appear to be promising for improving sleep.

Sleep and day-to-day PTSD symptom variability: an ecological momentary assessment and actigraphy monitored study in trauma-exposed young adults

BACKGROUND

Disrupted sleep and post-traumatic stress disorder (PTSD) are bi-directionally linked and have been found to mutually reinforce each other on a day-to-day basis. However, most of the previous research has focused on subjective measures of sleep only.

OBJECTIVE

Here, we investigated the temporal relationship between sleep and PTSD symptoms using both subjective (sleep diary) and objective measures of sleep (actigraphy).

METHODS

Forty-one non-treatment seeking, trauma exposed young adults (age M = 24.68, SD = 8.15) with a range of PTSD symptom severities (PTSS, 0-53 on PCL-5) were recruited. Participants completed two surveys per day over four weeks to measure day-time PTSD symptoms (i.e. PTSS and number of intrusions) and night-time sleep subjectively, while wearing an actigraphy watch to measure sleep objectively.

RESULTS

Linear mixed models revealed that subjectively reported sleep disruptions were associated with elevated next-day PTSS and increasing number of intrusive memories both within and between participants. Similar results were found for daytime PTSD symptoms on night-time sleep. However, these associations were not found using objective sleep data. Exploratory moderator analyses including sex (male vs. female) found that these associations differed in strength between sexes but were generally in the same direction.

DISCUSSION

These results were in line with our hypothesis with regards to the sleep diary (subjective sleep), but not actigraphy (objective sleep). Several factors which have implications on both PTSD and sleep, such as the COVID-19 pandemic and/ or sleep-state misperception, may be potential reasons behind those discrepancies. However, this study had limited power and needs to be replicated in larger samples. Nonetheless, these results add to the current literature about the bi-directional relationship between sleep and PTSD and have clinical implications for treatment strategies.

A low-threshold sleep intervention for improving sleep quality and well-being

BACKGROUND

Approximately one-third of the healthy population suffer from sleep problems, but only a small proportion of those affected receive professional help. Therefore, there is an urgent need for easily accessible, affordable, and efficacious sleep interventions.

OBJECTIVE

A randomized controlled study was conducted to investigate the efficacy of a low-threshold sleep intervention consisting of either (i) sleep data feedback plus sleep education or (ii) sleep data feedback alone in comparison with (iii) no intervention.

MATERIAL AND METHODS

A total of 100 employees of the University of Salzburg (age: 39.51 ± 11.43 years, range: 22-62 years) were randomly assigned to one of the three groups. During the 2-week study period, objective sleep parameters were assessed via actigraphy. In addition, an online questionnaire and a daily digital diary were used to record subjective sleep parameters, work-related factors, as well as mood and well-being. After 1 week, a personal appointment was conducted with participants of both experimental group 1 (EG1) and experimental group 2 (EG2). While the EG2 only received feedback about their sleep data from week 1, the EG1 additionally received a 45-min sleep education intervention containing sleep hygiene rules and recommendations regarding stimulus control. A waiting-list control group (CG) did not receive any feedback until the end of the study.

RESULTS

Results indicate positive effects on sleep and well-being following sleep monitoring over the course of 2 weeks and minimal intervention with a single in-person appointment including sleep data feedback. Improvements are seen in sleep quality, mood, vitality, and actigraphy-measured sleep efficiency (SE; EG1), as well as in well-being and sleep onset latency (SOL) in EG2. The inactive CG did not improve in any parameter.

CONCLUSION

Results suggest small and beneficial effects on sleep and well-being in people being continuously monitored and receiving (actigraphy-based) sleep feedback when paired with a single-time personal intervention.

Wearable-Measured Sleep and Resting Heart Rate Variability as an Outcome of and Predictor for Subjective Stress Measures: A Multiple N-of-1 Observational Study

The effects of stress may be alleviated when its impact or a decreased stress-resilience are detected early. This study explores whether wearable-measured sleep and resting HRV in police officers can be predicted by stress-related Ecological Momentary Assessment (EMA) measures in preceding days and predict stress-related EMA outcomes in subsequent days. Eight police officers used an Oura ring to collect daily Total Sleep Time (TST) and resting Heart Rate Variability (HRV) and an EMA app for measuring demands, stress, mental exhaustion, and vigor during 15-55 weeks. Vector Autoregression (VAR) models were created and complemented by Granger causation tests and Impulse Response Function visualizations. Demands negatively predicted TST and HRV in one participant. TST negatively predicted demands, stress, and mental exhaustion in two, three, and five participants, respectively, and positively predicted vigor in five participants. HRV negatively predicted demands in two participants, and stress and mental exhaustion in one participant. Changes in HRV lasted longer than those in TST. Bidirectional associations of TST and resting HRV with stress-related outcomes were observed at a weak-to-moderate strength, but not consistently across participants. TST and resting HRV are more consistent predictors of stress-resilience in upcoming days than indicators of stress-related measures in prior days.

How much does sleep vary from night-to-night? A quantitative summary of intraindividual variability in sleep by age, gender, and racial/ethnic identity across eight-pooled datasets

Habitual sleep duration and efficiency vary widely by age, gender, and racial/ethnic identity. Despite growing research on the importance of night-to-night, intraindividual variability (IIV) in sleep, few studies have examined demographic differences in sleep IIV. The present study describes typical sleep IIV overall and by demographics among healthy sleepers. Eight datasets of healthy sleepers (N = 2,404; 26,121 total days of sleep data) were synthesised to examine age, gender, and racial/ethnic identity differences in sleep IIV measured via diaries, actigraphy, and electroencephalography (EEG). Sleep IIV estimates included the intraindividual standard deviation (iSD), root mean square of successive differences (RMSSD), coefficient of variation (CV), and a validated Bayesian Variability Model (BVM). There was substantial IIV in sleep across measurement types (diary, actigraphy, EEG) for both sleep duration (iSD: 85.80 [diary], 77.41 [actigraphy], 67.04 [EEG] minutes; RMSSD: 118.91, 108.89, 91.93 minutes; CV: 19.19%, 19.11%, 18.57%; BVM: 60.60, 58.20, 48.60 minutes) and sleep efficiency (iSD: 5.18% [diary], 5.22% [actigraphy], 6.46% [EEG]; RMSSD: 7.01%, 7.08%, 8.44%; CV: 5.80%, 6.27%, 8.14%; BVM: 3.40%, 3.58%, 4.16%). Younger adults had more diary and actigraphy sleep duration IIV. Gender differences were inconsistent. White and non-Hispanic/Latinx adults had less IIV in sleep duration and efficiency compared to racial/ethnic minority groups. Even among healthy sleepers, sleep varies widely from night-to-night. Like mean sleep, there also may be disparities in IIV in sleep by demographic characteristics. Study results help characterise normative values of sleep IIV in healthy sleepers.

Testing the Pragmatic Effectiveness of a Consumer-Based Mindfulness Mobile App in the Workplace: Randomized Controlled Trial

BACKGROUND

Mental health and sleep problems are prevalent in the workforce, corresponding to costly impairment in productivity and increased health care use. Digital mindfulness interventions are efficacious in improving sleep and mental health in the workplace; however, evidence supporting their pragmatic utility, potential for improving productivity, and ability to reduce employer costs is limited.

OBJECTIVE

This pragmatic, cluster randomized controlled trial aimed to evaluate the experimental effects of implementing a commercially available mindfulness app-Calm-in employees of a large, multisite employer in the United States. Outcomes included mental health (depression, anxiety, and stress), sleep (insomnia and daytime sleepiness), resilience, productivity impairment (absenteeism, presenteeism, overall work impairment, and non-work activity impairment), and health care use (medical visit frequency).

METHODS

Employees were randomized at the work site to receive either the Calm app intervention or waitlist control. Participants in the Calm intervention group were instructed to use the Calm app for 10 minutes per day for 8 weeks; individuals with elevated baseline insomnia symptoms could opt-in to 6 weeks of sleep coaching. All outcomes were assessed every 2 weeks, with the exception of medical visits (weeks 4 and 8 only). Effects of the Calm intervention on outcomes were evaluated via mixed effects modeling, controlling for relevant baseline characteristics, with fixed effects of the intervention on outcomes assessed at weeks 2, 4, 6, and 8. Models were analyzed via complete-case and intent-to-treat analyses.

RESULTS

A total of 1029 employees enrolled (n=585 in the Calm intervention group, including 101 who opted-in to sleep coaching, and n=444 in waitlist control). Of them, 192 (n=88 for the Calm intervention group and n=104 for waitlist) completed all 5 assessments. In the complete-case analysis at week 8, employees at sites randomized to the Calm intervention group experienced significant improvements in depression (P=.02), anxiety (P=.01), stress (P<.001), insomnia (P<.001), sleepiness (P<.001), resilience (P=.02), presenteeism (P=.01), overall work impairment (P=.004), and nonwork impairment (P<.001), and reduced medical care visit frequency (P<.001) and productivity impairment costs (P=.01), relative to the waitlist control. In the intent-to-treat analysis at week 8, significant benefits of the intervention were observed for depression (P=.046), anxiety (P=.01), insomnia (P<.001), sleepiness (P<.001), nonwork impairment (P=.04), and medical visit frequency (P<.001).

CONCLUSIONS

The results suggest that the Calm app is an effective workplace intervention for improving mental health, sleep, resilience, and productivity and for reducing medical visits and costs owing to work impairment. Future studies should identify optimal implementation strategies that maximize employee uptake and large-scale implementation success across diverse, geographically dispersed employers.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05120310; https://clinicaltrials.gov/ct2/show/NCT05120310.

Exploring the Effects of Perceived Stress on the Within-Person Relationships Between Daily Activity Levels and Sleep in Women: An Ecological Momentary Assessment Study

BACKGROUND

Many studies show positive bidirectional associations between physical activity (PA) and sleep at the between-person level. There is an increased interest in investigating these associations at the within-person level. Few studies examined the effects of time-varying moderators on the within-person bidirectional associations between PA and sleep. This study aimed to examine the bidirectional within-person day-level associations between activity levels and self-reported sleep duration and explore the moderating effects of perceived stress on these day-level associations.

METHOD

Data from 158 women that included 7-day free-living monitoring over 4 measurement periods was analyzed using multilevel modeling to explore the moderating effects of daily stress on the bidirectional, within-person associations between activity levels and self-reported sleep duration. Moderate-to-vigorous PA (MVPA) and sedentary behavior (SB) were estimated from a waist-worn accelerometer. Self-reported sleep duration and perceived stress were collected by ecological momentary assessment.

RESULTS

No significant within-person associations between MVPA minutes and self-reported sleep duration were found in either direction. However, engaging in more MVPA than one's usual level was associated with longer sleep later that night when perceived stress was higher than usual (p = .04). Bidirectional negative within-person association between SB minutes and self-reported sleep duration was found (ps < .01). The negative association between SB and sleep duration later that night was stronger when perceived stress was lower than usual (p = .01).

CONCLUSION

Daily stress played an important role in the day-to-day associations between activity levels and sleep.

Bidirectional Relations Between Daily Stress and Sleep Among Black Emerging Adults

Background

Black adults experience higher levels of stress and more dysfunctional sleep patterns compared to their White peers, both of which may contribute to racial disparities in chronic health conditions. Dysfunctional sleep patterns are also more likely in emerging adults compared to other age groups. Daily stress–sleep relations in Black emerging adults are understudied.

Purpose

This study used ecological momentary assessment (EMA) and wrist-worn actigraphy to examine bidirectional associations between daily stress and sleep among Black emerging adults.

Methods

Black college freshmen (N = 50) completed an EMA protocol (i.e., five EMA prompts/day) and wore an accelerometer for 7 days. The first EMA prompt of each day assessed sleep duration and quality. All EMA prompts assessed stress. Wrist-worn actigraphy assessed nocturnal sleep duration, sleep onset latency, sleep efficiency, and waking after sleep onset.

Results

At the within-person level, stress experienced on a given day was not associated with any sleep metrics that night (p &gt; .05). On evenings when actigraphy-based sleep duration was shorter (B = −0.02, p = .01) and self-reported sleep quality was poorer (B = −0.12, p = .02) than usual, stress was greater the following day. At the between-person level, negative bidirectional relations existed between stress and actigraphy-based waking after sleep onset (stress predicting sleep: B = −0.35, p = .02; sleep predicting stress: B = −0.27, p = .04).

Conclusions

Among Black emerging adults, associations between daily sleep and stress vary at the between- and within-person level and are dependent upon the sleep metric assessed. Future research should compare these relations across different measures of stress and different racial/ethnic groups to better understand health disparities.

Daily relations between nap occurrence, duration, and timing and nocturnal sleep patterns in college students

OBJECTIVE/DESIGN

Sleep patterns change during college, and students may nap to compensate for lost sleep. Despite the increased prevalence of napping among students, few studies have investigated daily relations between napping and nocturnal sleep, as well as how timing of naps and nocturnal sleep might influence one another. The present study used daily diaries to capture the occurrence, timing, and duration of napping and relation to nocturnal sleep.

SETTING/PARTICIPANTS

Daily diary data, collected for 4-7 days, from 654 college students from a mid-sized midwestern university (81.5% female).

MEASUREMENT

Participants reported nightly sleep durations, bedtimes, and wake times as well as nap durations and nap start times.

RESULTS

Multilevel modeling (MLM) and multi-level logistic regressions revealed bidirectional relations between nocturnal sleep and napping. Regarding nocturnal sleep and its relation to next day napping, nocturnal sleep (including shorter duration and later bedtime) was associated with increased odds of napping and longer napping the following day. Shorter sleep duration was also associated with taking an earlier nap, while later bedtime was associated with a later nap the following day. Regarding napping and its association with same-night nocturnal sleep, taking a nap was associated with longer sleep duration that night, however, later nap start times and longer nap durations were associated with later bedtimes that night.

CONCLUSIONS

Findings provide evidence for bidirectional associations between napping and nocturnal sleep. Future studies are needed to explore how naps could be optimized to promote nocturnal sleep among college students, as well as for whom naps might be most beneficial.

Linking ethnic/racial discrimination to adolescent mental health: Sleep disturbances as an explanatory pathway

Ethnic/racial discrimination is associated with negative psychosocial outcomes, and this study considered sleep disturbance as a mediating pathway. Employing a combination of daily diary and biannual surveys, multilevel structural equation models estimated the indirect effects of sleep/wake concerns on negative, anxious, and positive mood, rumination, and somatic symptoms. In a sample of 350 urban Asian (74% Chinese, 8% Korean, 4% Indian, 1% Filipinx, 1% Vietnamese, and 12% other), Black, and Latinx (25% Dominican, 24% South American, 22% Mexican, 15% Puerto Rican, 5% Central American, and 9% other) youth (M = 14.27 years, 69% female, 77% U.S. born, 76% monoethnic/racial, data collected from 2015 to 2018), there was evidence for sleep disturbances mediating the impact of ethnic/racial discrimination on adjustment. Nighttime disturbance, daytime dysfunction, and daytime sleepiness evidenced partial or full mediation for daily- and person-level outcomes (υ = 0.1%-17.9%). Reciprocal associations between sleep disturbances and negative mood and rumination were also observed.

Sleep, stress and aggression: Meta-analyses investigating associations and causality

Prior research suggests that sleep is associated with increased subjective stress and aggression, but important questions remain about the typical magnitude of these relationships, as well as their potential moderators. We therefore conducted the first meta-analysis of this literature. Across 340 associational and experimental studies, significant associations were identified between sleep with both subjective stress (r = 0.307, p < .001) and aggression (r = 0.258, p < .001) in individuals from the general population, as well as between sleep with subjective stress (r = 0.425, p < .001) in individuals with sleep disorders. Experimental sleep restriction also led to increased subjective stress (g = 0.403, p = .017) and aggression (g = 0.330, p = .042). These findings suggest that poorer sleep is associated with - and leads to - heightened levels of subjective stress and aggression. These findings, and their implications, are discussed in relation to neurobiological literature, which highlights the complex interplay between metabolic activity in the brain, hormonal changes, and behavior.

Daily stress and sleep associations vary by work schedule: A between- and within-person analysis in nurses

Nurses experience poor sleep and high stress due to demanding work environments. Night shift work is common among nurses and may exacerbate stress-sleep associations. We examined bidirectional associations between daily stress and sleep, and moderation by recent shift worker status and daily work schedule among nurses. Participants were 392 nurses (92% female; 78% White, mean age = 39.54, SD = 11.15) who completed 14 days of electronic sleep diaries and actigraphy. They simultaneously completed assessments of daily stress and work schedule upon awakening (day shift vs. night shift [work between 9 p.m.-6 a.m.] vs. off work). Participants were classified as recent night shift workers if they worked at least one night shift during the past 14 days (n = 101; 26%). In the entire sample, greater daily stress predicted shorter self-reported total sleep time and lower self-reported sleep efficiency that night. Shorter self-reported and actigraphy total sleep time and lower self-reported sleep efficiency predicted higher next-day stress. Compared with recent night shift workers, day workers reported higher stress after nights with shorter total sleep time. Stress-sleep associations mostly did not vary by nurses' daily work schedule. Sleep disturbances and stress may unfold in a toxic cycle and are prime targets for tailored interventions among nurses. Night shift workers may be less susceptible to the effects of short sleep on next-day stress. Research is needed to understand the short- and long-term effects of shift work and address the unique sleep challenges nurses face.