A Cross-Sectional Study of the Associations between Chronotype, Social Jetlag and Subjective Sleep Quality in Healthy Adults

Associations between sleep problems in children with ADHD and parental insomnia and ADHD symptoms

Sleep problems are common in children with attention deficit hyperactivity disorder (ADHD). Children's sleep problem may influence, and be influenced by, parents' sleep problems as well as parents' ADHD symptoms. In the current study we examined the associations of parent-rated sleep quality and sleep timing of pre-adolescent children with parental insomnia symptoms, parental ADHD symptoms and dysfunctional attitudes and beliefs about sleep in a convenience sample recruited by advertisement (N = 120). Childhood sleep problems were common in the sample, with 82% of children exceeding the threshold for the presence of a paediatric sleep disorder. Children's sleep quality showed minimal association with their sleep timing and chronotype. Parental insomnia symptoms, ADHD symptoms and dysfunctional beliefs and attitudes about sleep all associated with their children's sleep quality, and with the sleep subdomains of sleep anxiety and parasomnias. In multiple regression analysis only parental insomnia score was a significant predictor of children's sleep quality. Children's bedtimes, wake times, sleep duration, chronotype or social jetlag did not associate with parents' ADHD or insomnia symptoms. Sleep quality was significantly poorer in children whose parents scored as both consistent for adult ADHD and probable for insomnia disorder compared to parents who scored as either ADHD consistent or insomnia probable, or those who parents scored as neither. We discuss the putative nature of the relationships between sleep quality of children with ADHD and parental ADHD and insomnia symptoms, and suggest that clinicians consider parental sleep when attending to children with ADHD.

The effects of social jetlag and sleep variability on sleepiness in a population-based study: The mediating role of sleep debt

Sleepiness is a multicausal condition, and previous research has highlighted associations between this symptom and the circadian timing system, specifically concerning social jetlag and sleep variability. Recent inquiries have shown that the effects of social jetlag on sleepiness can be confounded with the consequences of sleep debt. In light of the current evidence, we aimed to assess the effects of social jetlag and sleep variability on sleepiness and the potential mediating role of sleep debt. We used data from the EPISONO study, a cross-sectional population-based study with a sample size of 1042 participants, representative of the city of Sao Paulo, Brazil. Participants completed the UNIFESP Sleep Questionnaire (self-reported bedtime and get-up time) and the Epworth Sleepiness Scale (subjective daytime sleepiness). Subsequently, sleep-corrected mid-sleep time (chronotype), total sleep time, social jetlag (absolute difference between the mid-sleep time on workdays and mid-sleep time on free days), sleep variability (standard deviation of mid-sleep time), and sleep debt (difference between total sleep time on workdays and free days) were calculated. Generalised linear models were used to test whether social jetlag and sleep variability affected sleepiness. Mediation models were used to determine if any observed significant effects were mediated by sleep debt. The prevalence of social jetlag was 23% for >1 h and 12% for >2 h. The mean sleep variability was 41 ± 30 min. Social jetlag had a significant effect on the Epworth Sleepiness Scale scores. This association was no longer statistically significant after controlling for age, sex, body mass index, work schedule, and chronotype. A significant indirect effect of social jetlag on sleep debt and subsequently on the Epworth Sleepiness Scale scores was found. No effect of sleep variability on sleepiness could be identified. In conclusion, the association between social jetlag and sleepiness was mediated by sleep debt but was not independent of demographic, work, and chronotype variables. This study provides new evidence on the importance of circadian misalignment and sleep debt for sleep health on a population level.

Hemodialysis-induced chronodisruption and chronotype distribution in patients with chronic kidney disease

Changes in circadian rhythms have been observed in patients with chronic kidney disease (CKD), and evidence suggests that these changes can have a negative impact on health. This study aimed to investigate the existence of hemodialysis-induced chronodisruption, the chronotype distribution, and their association with sleep quality and quality of life (QoL). This was a cross-sectional study that enrolled 165 patients (mean age: 51.1 ± 12.5 y, 60.6% male) undergoing hemodialysis from three local units. The following instruments were used: the Morning-Eveningness Questionnaire (MEQ); a modified version of the Munich Chronotype Questionnaire (MCQT) to estimate hemodialysis-induced chronodisruption (HIC); the Kidney Disease QoL Short Form (KDQOL-SF); the Epworth Sleepiness Scale (ESS); the Pittsburgh Sleep Quality Index (PSQI) and the 10-Cognitive Screener (10-CS). HIC was present in 40.6% of CKD patients. Morning chronotype was prevalent in CKD patients (69%) compared to evening-type (17.1%) and significantly different from a paired sample from the general population (p < 0.001). HIC and chronotype were associated with different domains of QoL but not with sleep quality. This study suggests that there is a HIC and that morning chronotype is associated with CKD patients undergoing hemodialysis, with implications for QoL.

Stability of social jetlag and sleep timing into the second year of the Covid-19 pandemic: Results from a longitudinal study of a nationally representative adult sample in Ireland

The early phase of the COVID-19 pandemic has previously been associated with marked changes in sleep/wake timing arising from the imposition of society-wide infection mitigation measures. Such observations are considered of broader significance as they reveal the social pressures that sleep timing normally operates under. In order to assess how persistent such changes were as the COVID-19 pandemic developed, we assessed sleep timing and quality in a longitudinal study of a nationally-representative sample of Irish adults with data collected at two time-points (December 2021 and March 2021). Data on social jetlag and chronotype was derived from the micro Munich Chronotype Questionnaire from 830 and 843 participants who provided data in December 2020 and March 2021 respectively, of which 338 contributed data to both timepoints. Demographics and measures of insomnia symptoms, anxiety, depression and loneliness were also collected, and data was analysed both within-subjects and cross-sectionally within data waves. Social jetlag (the mismatch between sleep timing on "work" and "free" days) and other measures of sleep timing were stable across the two time-points, although insomnia symptoms improved slightly from December 2020 to March 2021. The mean social jetlag at both timepoints was ~ 30 minutes, considerably lesser than reported pre-pandemic levels in similar populations. Multiple regression analysis of cross-sectional data reveals that the timing of midsleep on "free" days was only a weak-to-moderate predictor of social jetlag, whilst hours worked per week was the strongest predictor of social jetlag. Requirement for "face-to-face" contact with the public at work and urban location of residence also emerged as predictors of social jetlag, although insomnia, anxiety and depression symptoms and loneliness rating did not. We conclude that sleep timing changes that occurred during the initial phase of the COVID-19 pandemic persisted into the second year of the pandemic, and these results further illustrate the key roles working practices and other social factors have in shaping social jetlag.

Association of social jetlag and eating patterns with sleep quality and daytime sleepiness in Japanese high school students

A high prevalence of excessive daytime sleepiness and poor sleep quality has been reported in adolescents, but the effects of social jetlag on sleep quality and daytime sleepiness are unclear. Therefore, we assessed the association of sleep and eating patterns with daytime sleepiness and sleep quality among a total of 756 Japanese high school students. Participants completed the Pittsburgh Sleep Quality Index to evaluate sleep quality, the Pediatric Daytime Sleepiness Scale to evaluate daytime sleepiness, and an 8-day sleep diary. Data on average sleep duration, social jetlag, midsleep on free days sleep corrected, and the differences in the first and last meal timing between school days and non-school days were obtained from participants' sleep diaries. The results reveal that social jetlag is associated with differences in the first meal timing between school days and non-school days, and that social jetlag of more than 2 hr is associated with extremely poor sleep quality and excessive daytime sleepiness in Japanese high school students. Our findings suggest that reducing social jetlag to within a 2-hr window is important to prevent poor sleep quality and excessive daytime sleepiness for this population.

Review: Identification and Management of Circadian Rhythm Sleep Disorders as a Transdiagnostic Feature in Child and Adolescent Psychiatry

OBJECTIVE

Sleep disturbances are highly frequent features in a range of child and adolescent psychiatric conditions. However, it is commonly not clear if such sleep problems represent symptomatic features of, comorbidities of, or risk factors for these conditions. It is believed that underlying dysfunction in the daily biological (circadian) clock may play important roles in the etiology of many sleep disorders, and circadian rhythm changes are reported in a number of neuropsychiatric conditions. The aim of this review was to explore the key identifying features of circadian rhythm disorders (CRDs) in child and adolescent psychiatry and address how such disorders may be managed in the clinic.

METHOD

A narrative review was conducted of the extant literature of CRDs in children and adolescents with psychiatric conditions.

RESULTS

Key biological and social factors that contribute to CRDs in children and adolescents, and the cognitive and neurobehavioral consequences resulting from insufficient sleep were outlined. The roles of melatonin and other chronotherapeutic and behavioral interventions for the management of CRDs were also outlined. Further, the importance of careful investigation of circadian rhythm abnormalities in shaping the most effective treatment plan according to chronobiological principles was highlighted.

CONCLUSION

CRDs are common in children and adolescents with psychiatric conditions and arise out of complex interactions between biological and social factors. Careful clinical attention to and management of CRDs in child and adolescent psychiatry have the potential for significant benefit not only in the domain of sleep but also in a range of cognitive, affective, and behavioral outcomes.

Chronotype and social support among student athletes: impact on depressive symptoms

Previous studies have shown individuals with evening chronotype to have a greater likelihood for depression (self-reported and clinical ratings), especially in young adults. However, the mechanisms for this relationship remain unknown. Low levels of social support may be a plausible mechanism: young adults with evening chronotypes are awake when others are sleeping, which may lead to feelings of isolation or low support. This study examined links between chronotype, depression, and social support in relationship subtypes within a group of university student athletes. Data were obtained from 189 NCAA Division-I student athletes across all sports. Chronotype was assessed with the Circadian Energy Scale and ranged from -2 (definitely morning type) to +2 (definitely evening type). Depressive symptoms were assessed with Center for Epidemiological Studies Depression scale. Social support was assessed with the Multidimensional Scale of Perceived Social Support, which included subscales for Family, Friends, and Significant Other. A subscale for Team was created using the items from the Friends subscale (changing the word "friends" to "teammates"). Regression analyses adjusted for age, sex, and minority status. More evening chronotype was associated with higher reported depressive symptoms (p = .018), lower overall perceived social support (p = .001), and lower perceived social support specifically provided by family (p < .0001), friends (p < .0001), and teammates (p = .014). However, more evening chronotype was associated with higher depressive symptoms for higher, but not lower perceived social support from significant other. Moreover, chronotype-by-support interactions on depressive symptoms were observed; the statistical relationship between chronotype and depression was evident only in those with low (but not high) social support from friends and teammates. These data suggest that having a more evening chronotype may be associated with social isolation, and decreased opportunities for interactions with friends and teammates. This may contribute to the long-standing circadian association seen with depression in college student-athletes. Interventions aimed at increasing university support networks may reduce the impact of depression in students self-identifying with later chronotypes and sleep schedules.

Biological Rhythm and Chronotype: New Perspectives in Health

The circadian rhythm plays a fundamental role in regulating biological functions, including sleep–wake preference, body temperature, hormonal secretion, food intake, and cognitive and physical performance. Alterations in circadian rhythm can lead to chronic disease and impaired sleep. The circadian rhythmicity in human beings is represented by a complex phenotype. Indeed, over a 24-h period, a person’s preferred time to be more active or to sleep can be expressed in the concept of morningness–eveningness. Three chronotypes are distinguished: Morning, Neither, and Evening-types. Interindividual differences in chronotypes need to be considered to reduce the negative effects of circadian disruptions on health. In the present review, we examine the bi-directional influences of the rest–activity circadian rhythm and sleep–wake cycle in chronic pathologies and disorders. We analyze the concept and the main characteristics of the three chronotypes.

Effects of societal-level COVID-19 mitigation measures on the timing and quality of sleep in Ireland

Objectives

Under usual circumstances, sleep timing is strongly influenced by societal imperatives. The sweeping whole-of-society measures introduced in response to the COVID-19 pandemic may represent a unique opportunity to examine the impact of large-scale changes in work practices on sleep timing. As such, we examined the impact of the travel restrictions and work from home orders imposed in Ireland in March 2020 on sleep timing and quality.

Methods

We utilized a cross-sectional survey deployed shortly after the imposition of restrictions which assessed current and retrospective ratings of sleep timing and quality; the final response set analysed was from 797 adults. Participants completed the ultra-short Munich Chronotype Questionnaire, the Pittsburg Sleep Quality Index, and answered questions pertaining to work status such as working from home during the period of restrictions.

Results and conclusion

There was a significant shift to later sleep start and end times, as well as delayed time of midsleep on both work and free days, during the period of restrictions. Sleep duration was longer for work days, while free day sleep duration was shorter and there was a reduction in social jetlag during the restrictions. Those who worked from home during restrictions had longer sleep duration on work day and had a significantly larger difference in sleep end on work day than “essential” workers who continued to attend their normal place of work.

Time Perspective and Bedtime Procrastination: The Role of the Chronotype-Time Perspective Relationship

INTRODUCTION

Bedtime procrastination (BP) has a close relationship with one's chronotype, from a biological perspective on time. However, it remains unknown whether there is an association between BP and psychological time. Therefore, the aim of the present study was to evaluate the relationship between time perspective (TP) and BP and the effect of TP on the relationship between BP and chronotype by examining a sample of college students pre- and post-COVID-19 outbreak.

METHODS

A total of 628 Chinese students (267 in pre-outbreak and 361 in post-outbreak) validly completed the Chinese version of the Bedtime Procrastination Scale, the Zimbardo Time Perspective Inventory (ZTPI), and the Morningness-Eveningness Questionnaire.

RESULTS

Students with more BP behaviors exhibited greater deviation from a balanced TP, especially after the COVID-19 outbreak. Hierarchical regression analyses revealed that the past-negative and future orientations, as operationalized by the ZTPI, contributed independently to BP behaviors. The structural equation modeling analyses further demonstrated that morningness was significantly related to a more future-oriented TP, which in turn decreased BP in pre- and post-COVID-19 outbreak samples, while morningness was associated with a less past-negative-oriented TP, which in turn decreased BP only in the post-COVID-19 outbreak sample.

CONCLUSION

This study indicated that TP in students with BP predominantly focused on future orientation and that TP can mediate the relationship between chronotype and BP behaviors. However, the COVID-19 pandemic may disrupt the time flow and change the role of chronotype-TP in BP. These findings explain how individual differences in TP are associated with BP, which may be helpful in designing effective interventions to avoid BP, from the viewpoint of time perspective therapy.

Association of mid sleep time and social jetlag with psychosocial behaviour of Indian population during COVID-19 lockdown

Background: India, being the third worst affected country from COVID-19 pandemic at the time of study, faced complete lockdown to minimize community transmission that confined people to social isolation for extended durations.

Design and Methods: Therefore, we conducted an online questionnaire-based survey for the Indian population after 37 days of complete lockdown to assess the integrative effects of such home restriction and social isolation on mid-sleep time, social jetlag, and their associated psychosocial behavior. From the reports of sleep onset and waking-up times before and during lockdown as obtained from a total of 1511 respondents of ≥18 years, midsleep time (MST) and social jetlag (SJL) were calculated. Participants also rated their psychosocial behavior related variables on a Likert scale.

Results: Significantly delayed MST was noted during the lockdown. The majority showed reduced social jetlag; however, younger people and female subjects exhibited more SJL with delay in MST. Also, delayed MST and elevated SJL problems were more clearly demonstrated in people exhibiting more disturbances in sleep quality and daily routine, lower general mood status, irregular feeding habits (snacking frequency), worsened personal relationship, quality of life, and increased daydreaming events.

Conclusion: The study emphasizes the importance of maintaining a regular daily routine with respect to sleep-wake patterns and eating habits to minimize the impact of such a crisis situation on sleep behavior, social jetlag, and associated psychosocial wellbeing.

Effects of the COVID-19 lockdown on human sleep and rest-activity rhythms

In modern societies, human rest–activity rhythms and sleep result from the tensions and dynamics between the conflicting poles of external social time (e.g., work hours and leisure activities) and an individual’s internal biological time. A mismatch between the two has been suggested to induce ‘social jetlag’ [1] and ‘social sleep restriction’, that is, shifts in sleep timing and differences in sleep duration between work days and free days. Social jetlag [2,3] and sleep restrictions [4] have repeatedly been associated with negative consequences on health, mental wellbeing, and performance. In a large-scale quasi-experimental design, we investigated the effects of the phase with the most rigorous COVID-19 restrictions on the relationship between social and biological rhythms as well as sleep during a six-week period (mid-March until end of April 2020) in three European societies (Austria, Germany, Switzerland). We found that, on one hand, the restrictions reduced the mismatch between external (social) and internal (biological) sleep–wake timing, as indexed by significant reductions in social jetlag and social sleep restriction, with a concomitant increase in sleep duration. Sleep quality on the other hand was slightly reduced. The improved individual sleep–wake timing can presumably be attributed to an increased flexibility of social schedules, for instance due to more work being accomplished from home. However, this unprecedented situation also led to a significant increase in self-perceived burden, which was attendant to the decrease in sleep quality. These adverse effects may be alleviated by exposure to natural daylight as well as physical exercise.