Delayed sleep-wake phase disorder in young adults: prevalence and correlates from a national survey of Norwegian university students

Development and validation of the Japanese version of the Bedtime Procrastination Scale (BPS-J)

BACKGROUND

The average sleep duration of Japanese people is shorter than that of people from other countries, and bedtime procrastination is suspected to be one of the factors contributing to this issue. This study aimed to develop and validate the Japanese version of the Bedtime Procrastination Scale (BPS-J).

METHODS

The BPS-J was developed through procedures including the translation and back-translation of the scale, cognitive interviews with 100 participants who reported having experiences of being diagnosed with insufficient sleep syndrome (ISS) or receiving treatment for ISS using open-ended online questionnaires, and expert checking. To investigate the scale's validity and reliability, an online survey was conducted with daytime workers aged 20 - 65 years without a history of sleep disorders other than ISS. Half the participants were retested using the same survey after 14 days. Participants' responses to the Brief Self-Control Scale (BSCS), General Procrastination Scale (GPS), and Munich ChronoType Questionnaire (MCTQ), and data on sleep-related variables such as sleep duration on workdays and the days per week of fatigue or sleep loss, sex, and age, were collected.

RESULTS

We analyzed data from 574 participants to assess scale validity. We then analyzed data from 280 participants to determine test-retest reliability. Confirmatory factor analyses revealed that the two-factor model without Item 2 was most suitable for the BPS-J, unlike other language versions. Regardless of the full-item model or the model with Item 2 eliminated, sufficient reliability and significant correlations with the BSCS, GPS, MCTQ, and sleep-related variables such as sleep duration per night on work days, days per week of feeling fatigued, and days per week of sleep loss were observed. Logistic and linear regressions showed that the relationships between the BPS-J, sleep-related variables, and MCTQ were maintained after adjusting for sex and age.

CONCLUSION

The BPS-J had sufficient validity and reliability. Further, eliminating Item 2 from the original version of the BPS strengthened the ability to survey Japanese daytime workers.

Longitude-based time zone partitions and rates of suicide

BACKGROUND

Increasing evidence suggests that conditions with decreased morning and increased evening light exposure, including shift work, daylight-saving time, and eveningness, are associated with elevated mortality and suicide risk. Given that the alignment between the astronomical, biological, and social time varies across a time zone, with later-shifted daylight exposure in the western partition, we hypothesized that western time zone partitions would have higher suicide rates than eastern partitions.

METHODS

United States (U.S.) county-level suicide and demographic data, from 2010 to 2018, were obtained from a Centers for Disease Control database. Using longitude and latitude, counties were sorted into the western, middle, or eastern partition of their respective time zones, as well as the northern and southern halves of the U.S. Linear regressions were used to estimate the associations between suicide rates and time zone partitions, adjusting for gender, race, ethnicity, age group, and unemployment rates.

RESULTS

Data were available for 2872 counties. Across the U.S., western partitions had statistically significantly higher rates of suicide compared to eastern partitions and averaged up to two additional yearly deaths per 100,000 people (p < .001).

LIMITATIONS

Ecological design and limited adjustment for socioeconomic factors.

CONCLUSIONS

To our knowledge, this is the first study of the relationship between longitude-based time zone partitions and suicide. The results were consistent with the hypothesized elevated suicide rates in the western partitions, and concordant with previous reports on cancer mortality and transportation fatalities. The next step is to retest the hypothesis with individual-level data, accounting for latitude, photoperiodic changes, daylight-saving time, geoclimatic variables, physical and mental health indicators, as well as socioeconomic adversity and protection.

Delayed sleep phase disorder during the COVID-19 pandemic and its health implications

Circadian rhythm sleep disorders are alterations that are characterized by a shift in the sleep-wake cycle relative to day and night, such as the delayed sleep phase disorder (DSPD), which is a retard of at least 2 hours in the sleep start. Typically, the patient falls asleep after 2 a.m. and wakes up after 10 a.m. and with symptom of sleep onset insomnia. The prevalence of DSPD in young adults is 0.48%, increasing to 3.3% in adolescents. Interestingly, patients with COVID-19 infection report anxiety due to the intensive care unit lockdown and constant exposure to bright light. In addition, post-COVID patients have an increased risk of developing DSPD. For example, in adolescent post-COVID patients, the prevalence of DSPD increases to 63.3%. Patients with DSPD also have alterations in metabolic health, poor school performance, cognitive impairment, and a higher risk of developing other diseases. The objective of the present review is therefore to describe the characteristics of DSPD during the COVID-19 pandemic and to outline its possible implications for physical health (eg, metabolism) and mental health (eg, anxiety or depression).

The optimal dose of Ramelteon for the better treatment adherence of delayed sleep-wake phase disorder: a dropout rate study

Background

Evidence regarding the effectiveness of melatonin receptor agonists in treating delayed sleep-wake phase disorder (DSWPD) remains limited. This study aimed to determine the optimal dose of ramelteon, a melatonin receptor agonist, for the better treatment adherence of DSWPD.

Methods

The patients who were diagnosed definitely as having DSWPD by board-certified physicians specialized in sleep medicine and started to receive strategically timed ramelteon medications after the diagnosis were included. Data on the initial ramelteon dose and follow-up duration (up to 24 months) were collected retrospectively. Patients with treatment discontinuation, changes in ramelteon dose, or the addition of other sleep-related medications were considered dropouts. Kaplan-Meier estimates, log-rank tests, and Cox regression analyses were performed.

Results

Overall, 373 patients were analyzed. The findings revealed that the 2 mg dose of ramelteon was associated with a lower dropout rate compared to the other doses (8 mg, 4 mg, and 1 mg). The dropout rate for the 2 mg group was estimated to have a hazard ratio (HR) of 0.5762 when compared with the 8 mg dose group. Sex did not reveal a significant HR, whereas older age exhibited a small but significant HR (0.9858).

Conclusion

For achieving better adherence, a dosing regimen of strategically timed 2 mg ramelteon may be the best for the treatment of DSWPD. The therapeutic dose window for better adherence seems to center approximately 2 mg of ramelteon. Furthermore, caution should be exercised when treating younger patients to prevent dropouts.

Physical activity and morningness: A helpful combination in improving the sleep quality of active Italian university students

University students are commonly described as having worsened sleep quality, especially when inactive and Evening-type (E-type) subjects. This study aimed to examine the interactions between physical activity and chronotype on sleep quality among a sample of active Sports Science university students. In November 2019, 433 participants (mean age: 19.7 ± 1.56 years; 70% males) completed the Pittsburgh Sleep Quality Index, the Godin-Shepard Leisure-Time Physical Activity Questionnaire (tertiles categorisation), and the Morningness-Eveningness Questionnaire. Females and E-type slept significantly worse than males and Neither-(N-types) and Morning-types (M-types), respectively. However, there were no significant differences in sleep quality based on physical activity levels. The three-way ANOVA revealed that sleep quality in N- and E-types appeared to be independent of physical activity, whereas M-types showed an improvement in sleep classification with increased physical activity. Moderation analysis indicated that physical activity significantly moderated the relationship between chronotypes and sleep quality. Specifically, M-types demonstrated a more pronounced improvement in sleep quality with increasing physical activity compared to the other chronotypes. In conclusion, M-type university students derived the greatest benefits from physical activity in improving sleep quality. Conversely, physical activity seemed to have a limited impact on sleep quality among active E-type university students.

Parental drinking, mental health and educational level, and offspring's subsequent prescription drugs treatment for sleep problems. A longitudinal HUNT survey and registry study

BACKGROUND

Parental drinking, mental health and family socioeconomic status are all associated with offspring sleep problems, but there is a paucity of research that considers the effect of risk factors, as they co-occur within and across families. Also, sleep problems are closely linked with mental health problems. Disentangling the effects on one or the other are important. We examined whether parental risk constellations are differently associated with offspring's subsequent prescription drug use for sleep problems during nine years with or without prescription drug use for anxiety and/or depression.

METHODS

The sample included 8773 adolescent offspring of 6696 two-parent families who participated in the Nord-Trøndelag Health Study in Norway. The exposures were five parental risk constellations, previously identified via Latent Profile Analysis, characterized by drinking frequencies and quantities, mental health, and years of education. The outcomes were dispensed prescription drugs in offspring during 2008-2016 for (a) only sleep problems (b) sleep problems and anxiety/depression or (c) only anxiety/depression. We used multinomial logistic regression to model the odds of the outcomes.

RESULTS

Compared to the overall low-risk parental constellation, none of the risky constellations were significantly associated with increased risk of being dispensed prescription drugs only for sleep problems. Offspring from two different risk profiles were at increased risk for being dispensed both sleep and anxiety/depression prescription drugs. These were parental profiles marked by (1) low education, symptoms of mental health problems and weekly binge drinking in both parents (OR 1.90, CI = 1.06;3.42); and (2) frequent heavy drinking in both parents and symptoms of mental health problems in fathers (OR 3.32, CI = 1.49;7.39). Offspring from the risk profile with lowest parental education had increased risk of only anxiety/depression prescription drugs (OR 1.25, CI = 1.05;1.49).

CONCLUSION

Our findings suggest that parental risk constellations are not associated with increased risk of offspring receiving sleep medications without also receiving anxiety/depression medications, as two risk constellations were associated with increased risk of dispensation of both sleep and anxiety/depression prescription drugs. Receiving both may be an indication of severity. The findings underscore the importance of including measures of mental health problems when investigating sleep problems to avoid misattribution of effects.

Self-Directed Home-Based Dim-Light Melatonin Onset Collection: The Circadia Pilot Study

Study Objectives

To test the feasibility of a novel at-home salivary Dim Light Melatonin Onset (DLMO) assessment protocol to measure the endogenous circadian phase of 10 individuals ( 1 Advanced Sleep-Wake Phase Disorder patient (ASWPD), 4 Delayed Sleep-Wake Phase Disorder patients (DSWPD), and 5 controls).

Methods

The study involved 10 participants (sex at birth: females = 9; male= 1), who ranged between 27 to 63 years old, with an average age of 38 years old. Our study population consisted of 7 individuals who identified as white and 3 who identified as Asian. Our participants were diverse in gender identity (woman = 7, male = 1, transgender = 1, nonbinary = 1, none = 1).The study tracked the sleep and activity patterns of 10 individuals over a 5-6 week period using self-reported online sleep diaries and objective actigraphy data. Participants completed two self-directed DLMO assessments, approximately one week apart, adhering to objective compliance measures. Participants completed the study entirely remotely: they completed all sleep diaries and other evaluations online and were mailed a kit with all materials needed to perform the actigraphy and at-home sample collections.

Results

Salivary DLMO times were calculated for 8/10 participants using the Hockeystick method. DLMO times were on average 3 hours and 18 minutes earlier than self-reported sleep onset times (DSPD: 12:04 AM, controls: 9:55 PM.) Among the 6 participants for whom we calculated two separate DLMO times, DLMOs 1 and 2 were 96% correlated (p<0.0005.).

Conclusions

Our results indicate that self-directed, at-home DLMO assessments are feasible and accurate. The current protocol may serve as a framework to reliably assess circadian phase in both clinical and general populations.

Delayed sleep-wake phase disorder and its related sleep behaviors in the young generation

Delayed sleep-wake phase disorder (DSWPD) is a sleep disorder in which the habitual sleep-wake timing is delayed, resulting in difficulty in falling asleep and waking up at the desired time. Patients with DSWPD frequently experience fatigue, impaired concentration, sleep deprivation during weekdays, and problems of absenteeism, which may be further complicated by depressive symptoms. DSWPD is typically prevalent during adolescence and young adulthood. Although there are no studies comparing internationally, the prevalence of DSWPD is estimated to be approximately 3% with little racial differences between Caucasians and Asians. The presence of this disorder is associated with various physiological, genetic and psychological as well as behavioral factors. Furthermore, social factors are also involved in the mechanism of DSWPD. Recently, delayed sleep phase and prolonged sleep duration in the young generation have been reported during the period of COVID-19 pandemic-related behavioral restrictions. This phenomenon raises a concern about the risk of a mismatch between their sleep-wake phase and social life that may lead to the development of DSWPD after the removal of these restrictions. Although the typical feature of DSWPD is a delay in circadian rhythms, individuals with DSWPD without having misalignment of objectively measured circadian rhythm markers account for approximately 40% of the cases, wherein the psychological and behavioral characteristics of young people, such as truancy and academic or social troubles, are largely involved in the mechanism of this disorder. Recent studies have shown that DSWPD is frequently comorbid with psychiatric disorders, particularly mood and neurodevelopmental disorders, both of which have a bidirectional association with the pathophysiology of DSWPD. Additionally, patients with DSWPD have a strong tendency toward neuroticism and anxiety, which may result in the aggravation of insomnia symptoms. Therefore, future studies should address the effectiveness of cognitive-behavioral approaches in addition to chronobiological approaches in the treatment of DSWPD.

Joint Contributions of Depression and Insufficient Sleep to Self-Harm Behaviors in Chinese College Students: A Population-Based Study in Jiangsu, China

Self-harm in young people is common, and previous studies have shown that insufficient sleep or depression was associated with self-harm. However, the joint association of insufficient sleep and depression with self-harm is unknown. We employed representative population-based data from the "Surveillance for Common Disease and Health Risk Factors Among Students in Jiangsu Province 2019" project. College students reported their self-harm behavior over the past year. Rate ratios (RRs) and corresponding 95% confidence intervals (CIs) for self-harm in relation to sleep and depression were modeled using negative binomial regression with a sample population as an offset, adjusting for age, gender, and region. The instrumental variable approach was used for the sensitivity analyses. Of the study population, approximately 3.8% reported self-harm behaviors. Students with sufficient sleep experienced a lower risk of self-harm than those with insufficient sleep. Compared with students with sufficient sleep and the absence of depression, the adjusted risk of self-harm was elevated 3-fold (1.46-4.51) in those reporting insufficient sleep in the absence of depression, 11-fold (6.26-17.77) in those with sufficient sleep and definite depression, and 15-fold (8.54-25.17) in those with both insufficient sleep and definite depression. The sensitivity analyses indicate that insufficient sleep remained a contributing risk factor for self-harm. Lack of sleep in young people is significantly associated with self-harm, particularly in the presence of depression. The provision of mental health care and attention to sleep deprivation are particularly important for college students.

Melatonin for sleep disorders in people with autism: Systematic review and meta-analysis

Melatonin is a potential therapeutic intervention for improving sleep quality in people with autistic spectrum disorder (ASD). We investigate the effect of using melatonin as a sleep disorder treatment in people with ASD. Interventionist studies were searched in seven databases. A total of 595 references were identified, 15 of which were eligible for the systemic review and meta-analysis. Melatonin use presented a positive effect on total sleep time (standardized mean difference- SMD = 0.78; 95%CI = 0.35; 1.21; I² = 91%), on sleep latency (SMD = 1.23; 95%CI = 0.35; 2.11; I² = 94%), and on sleep efficiency (SMD = -0.70; 95%CI = -1.23; -0.16; I² = 91%) when comparing the intervention group with the placebo/control group via the global analysis. According to the global analysis, the wake after sleep onset and night awakening parameters were not statistically significant. Melatonin has possible efficacy over total time, latency, and efficiency sleep parameters.

Validation of the Self-Rating of Biological Rhythm Disorder for Adolescents (SBRDA) Scale by Dim Light Melatonin Onset in Healthy Young Adults

Understanding the biological rhythms that influence young adult health is vital because the combination of biological changes and a circadian phase delay lead to young adults being at high risk of circadian misalignment. We have previously established a self-rating of biological rhythm disorder for adolescents (SBRDA). However, we did not externally validate the SBRDA against objective measures of biological rhythms such as dim light melatonin onset (DLMO)-the gold standard of the endogenous circadian phase. The purpose of this study was to verify the effectiveness of SBRDA in identifying individuals with biological rhythm disorders. Our participants were 42 (47.2%) boys and 47 (52.8%) girls with an average age of 18.5 ± 1.2 years. Saliva samples were collected from 4 h before bed time to 2 h after sleep every 60 min in a dim-light (<50 lx) laboratory environment. Biological rhythm parameters were assessed using questionnaires, including SBRDA, MEQ, and MCTQ. The mean DLMO time (h) was 22.2 ± 1.9. The DLMO correlated significantly with the SBRDA score (r = 0.33, p < 0.001), MEQ score (r = -0.24, p < 0.05), and MSFsc (r = 0.26, p < 0.05). ROC curve analysis showed that SBRDA was of diagnostic value for biological rhythm disorder (p < 0.05). Our observations demonstrate that SBRDA, which is consistent with MEQ and MCTQ, can be used to reflect endogenous circadian rhythm disorders in young adults. Exposure to dim light may activate melatonin secretion and lead to an earlier peak in young adults with biological rhythm disorder.

Genetics of circadian rhythms and sleep in human health and disease

Circadian rhythms and sleep are fundamental biological processes integral to human health. Their disruption is associated with detrimental physiological consequences, including cognitive, metabolic, cardiovascular and immunological dysfunctions. Yet many of the molecular underpinnings of sleep regulation in health and disease have remained elusive. Given the moderate heritability of circadian and sleep traits, genetics offers an opportunity that complements insights from model organism studies to advance our fundamental molecular understanding of human circadian and sleep physiology and linked chronic disease biology. Here, we review recent discoveries of the genetics of circadian and sleep physiology and disorders with a focus on those that reveal causal contributions to complex diseases.

Bidirectional associations between sleep problems and behavioural difficulties and health-related quality of life in adolescents: Evidence from the SCAMP longitudinal cohort study

Background

Sleep problems show associations with negative outcomes in both physical and mental health in adolescents, but the associations may be reciprocal. We aimed to assess bidirectional associations between sleep problems and mental health symptoms including behavioural difficulties (internalising and externalising difficulties) and low health-related quality of life (HRQoL).

Methods

A total of 6616 adolescents (52.4% females) across Greater London completed baseline assessments when they were aged 11-12 years, and 3803 of them (57.2% females) completed follow-up assessments at aged 13-15 years. Weekday and weekend sleep duration were derived from self-reported bedtime, sleep onset latency and wake time. Sleep disturbance was assessed using a standardized sleep disturbance scale. Internalising and externalising difficulties were assessed using subscales of the Strength and Difficulties Questionnaire. HRQoL was assessed using the KIDSCREEN-10 questionnaire. Cross-lagged structural equation modelling was used with multiple imputation to examine bidirectional associations between sleep problems and mental health symptoms.

Results

Females had greater internalising difficulties, worse HRQoL and more sleep disturbance than males. Persistent insufficient weekday and weekend sleep, and sleep disturbance (i.e., at both baseline and follow-up) were associated with internalising and externalising difficulties and low HRQoL at follow-up (ORs ranged from 1.53 to 3.63). Persistent externalising difficulties and low HRQoL were also associated with insufficient weekend sleep and sleep disturbance at follow-up (ORs ranged from 1.68 to 4.25). Using continuous variables, we found bidirectional associations between weekday sleep duration and HRQoL, weekend sleep duration and externalising score, sleep quality and internalising score, and sleep quality and HRQoL. The association magnitudes were mostly similar in the two directions.

Conclusions

Our study showed bidirectional associations between sleep problems and mental health symptoms during adolescence, indicating that early intervention and treatment on the first-occurring symptom may prevent the development of subsequent problems.

Prevalence and Factors Associated With the Risk of Delayed Sleep-Wake Phase Disorder in Japanese Youth

BACKGROUND

Delayed sleep-wake phase disorder (DSWPD) is more prevalent among the younger generation. However, the prevalence of this disorder in Asia, particularly Japan, has not yet been elucidated. Furthermore, the impact of DSWPD morbidity on daytime functioning and factors associated with the presence of the disorder remain unclear.

METHODS

A web-based survey was conducted among youth aged 15-30 years. In total, 7,810 individuals completed the questionnaire. The questionnaire included items on sociodemographic variables as well as the Japanese version of the Biological Rhythms Interview of Assessment in Neuropsychiatry self-report (J-BRIAN-SR), which assesses the risk of DSWPD, sleep behaviors and possibly related lifestyle variables, productivity loss [WHO Health and Work Performance Questionnaire (HPQ)], and health-related quality of life (HRQOL). The risk of DSWPD was indicated by a J-BRIAN-SR score greater than or equal to 40 points and days of absence ≥4 days per month. After comparing these variables for participants at risk of DSWPD and those who were not, the factors associated with the risk of DSWPD were examined using logistic regression analysis, with sociodemographic and lifestyle variables as independent variables.

RESULTS

The overall prevalence of participants at risk DSWPDs was 4.3%. Compared with participants without DSWPD, those at risk of DSWPD presented significantly worse HPQ and HRQOL scores. The risk of DSWPD was positively associated with the presence of currently treated diseases, length of nighttime liquid crystal display (LCD) viewing, and being a high school/university students. It was negatively associated with habitual exercise.

CONCLUSION

The risk of DSWPD seemed to be consistent with reports from Western countries, and individuals possibly affected by the disorder were thought to have deteriorated daytime functioning. In addition, lifestyle specific to youth, such as long-term LCD viewing at night and relatively loose social constraints, could be associated with the presence of DSWPD in this generation.

The Clinical Effect of Blue Light Therapy on Patients with Delayed Sleep-Wake Phase Disorder

OBJECTIVE

To investigate the feasibility and patient acceptance of applying blue light glasses to treat delayed sleep-wake phase disorder (DSWPD).

METHODS

Fifteen patients with DSWPD were collected as the observation group and 15 healthy people as the control group. The patients wore blue light glasses with a continuous radiation wavelength of about 470 nm for 1h to 2h during the period from 06:30 to 09:00 in the morning after waking up, respectively. Assessment of Hamilton Anxiety Scale 14 items (HAMA14), Hamilton Depression Rating Scale 24 items (HAMD24), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Morningness-Eveningness Questionnaire (MEQ), and Insomnia Severity Index (ISI) scores before and after 1 week of treatment. Pearson correlation was used to analyze the correlation between the efficacy of patients with sleep-wake phase delay disorder and HAMA14, HAMD24, PSQI, ISI, ESS, MEQ, SL (sleep time), TST (total sleep time), TTiB (total time in bed), SQ (sleep quality), TOA (total arousal time), WASO (wake after sleep onset), AAT (average arousal time), and SE (sleep efficiency percent). Multi-factor logistic regression analysis of factors influencing the efficacy of patients with sleep-wake phase delay disorder.

RESULTS

After treatment, PSQI-G scores, number of nighttime awakenings and time of awakening recorded in the sleep diary decreased significantly in the observation group (P < 0.05), and subjective sleep quality and MEQ scores increased (P < 0.05). MEQ score shifted from "moderate night type" to "intermediate type", sleep-wake phase tended to shift forward. The total PSQI score and Pittsburgh Sleep Quality Index Global (PSQI-G) score were significantly lower in the control group after treatment (P < 0.05). By Pearson correlation analysis, the efficacy of patients with sleep-wake phase delay disorder was significantly correlated with HAMA14, HAMD24, PSQI, ISI, ESS, MEQ, SL, TST, TTiB, SQ, TOA, WASO, AAT, and SE. Multifactorial logistic regression analysis revealed that the factors influencing the efficacy of patients with sleep-wake phase delay disorder were PSQI, ISI, ESS, MEQ, SL, TST, TTiB, SQ, TOA, WASO, AAT, and SE.

CONCLUSION

Blue light therapy has a positive effect on improving subjective sleep quality, reducing the number of nocturnal awakenings and the duration of nocturnal awakenings, improving daytime function, and shifting the sleep phase forward in patients with DSWPD. Blue light therapy improves subjective sleep quality and daytime function the following day in normal individuals.