Association between puberty and delayed phase preference

Morningness-Eveningness Questionnaire: Reliability and factorial structure of the full and reduced versions in Spanish adolescents

This study analyzed the suitability of the Morningness-Eveningness Questionnaire (MEQ) for Spanish adolescents, focusing on reliability, structure, and age/sex invariance. 2,268 adolescents (49.1% girls, aged 12-17) participated. Four MEQ items were unsuitable, leading to a 15-item version (MEQ-15) with good reliability and fit to a bifactor model: general morningness-eveningness factor and awakening time, sleep time, and time of greatest efficiency factors. The reduced MEQ (rMEQ) also fit a one-factor model. Sex and age invariance were tenable for the general factor of MEQ-15 and rMEQ. Morningness declines during adolescence, with boys showing more morningness than girls. Both versions show good psychometric properties.

Chronotype, sleep, and glycemic control in children and adolescents with type 1 diabetes: a case-control study

OBJECTIVES

This study aimed to explore the relationships between sleep parameters, chronotype preferences, and glycemic control in children and adolescents with type 1 diabetes (T1DM), compared to healthy peers.

METHODS

A total of 96 children and adolescents with T1DM and 95 healthy controls aged 8-18 years participated in this case-control study. Anthropometric measurements were collected, and participants completed the Munich Chronotype Questionnaire and the Pittsburgh Sleep Quality Index (PSQI). Glycemic control was assessed using HbA1c levels.

RESULTS

Children with T1DM demonstrated significantly shorter sleep durations, poorer sleep quality, and a later chronotype compared to controls (p<0.05). Poor glycemic control (HbA1c>7.5 %) was observed in 72.9 % of the T1DM group, with 34.3 % exhibiting very poor control (HbA1c>9 %). Logistic regression identified poor sleep quality (PSQI score, OR: 1.47, p<0.001) and later chronotype (OR: 5.14, p<0.01) as independent predictors of poor glycemic control. Generalized linear modeling (GLM) further revealed significant associations between HbA1c levels, insulin dosage (p<0.001), and chronotype (p=0.090).

CONCLUSIONS

Late chronotype and poor sleep quality are closely linked to suboptimal glycemic control in pediatric T1DM populations. These findings underscore the importance of integrating sleep-focused strategies into routine diabetes management.

The hidden clock: how chronotype is related to depression, anxiety, and stress in adolescents - insights from the EHDLA study

BACKGROUND

Depression, anxiety, and stress symptoms are common among adolescents; however, studies exploring their relationship with chronotype in European youth populations is scarce. This study aimed to evaluate the association between chronotype status and depression, anxiety, and stress symptoms in adolescents.

METHODS

A secondary analysis of the Eating Healthy and Daily Life Activities (EHDLA) cross-sectional study was performed in 703 adolescents (56.3% girls) between 12 and 17 years from the Valle de Ricote, Spain. Chronotype preference was assessed using the Morningness/Eveningness Scale in Children (MESC), while symptoms were evaluated using the Depression, Anxiety, and Stress Scale (DASS-21). A robust generalized linear regression model was used to evaluate the associations between chronotype prefernces and symptoms of depression, anxiety and stress in adolescents.

RESULTS

After adjusting for potential covariates (sex, age, socioeconomic status, body mass index, sleep duration, physical activity, sedentary behavior, and energy intake), the highest probability of having depression, anxiety, and stress was identified in those with an eveningness chronotype preference (depression: 27.4%, 95% confidence interval [CI] 17.5-40.1%; anxiety: 28.5%, 95% CI 18.6-41.0%; stress: 47.6%, 95% CI 34.1-61.5%). Conversely, the lowest probability was observed in adolescents with a morningness chronotype preference (depression: 11.9%, 95% CI 8.3-16.8%; anxiety: 15.4%, 95% CI 11.2-28.9%; stress: 19.5%, 95% CI 14.7-25.5%). Significant differences were found when comparing participants with the eveningness chronotype to those with a morningness or intermediate chronotype preference (p < 0.05 for all comparisons).

CONCLUSIONS

Depression, anxiety, and stress symptoms were more likely in adolescents with an eveningness chronotype preference than in those with morningness or intermediate chronotypes. Chronotype preferences should be taken into account for developing interventions that promote better mental health and healthy sleep habits in adolescents.

Sleep Hygiene Among Adolescents Clinically Referred to Behavioral Sleep Medicine: Comparisons to the Validation Sample and Associations with Sleep Problems

OBJECTIVES

1) Compare the sleep hygiene of our clinical sample to the community-based validation sample and established clinical thresholds and 2) clarify the relationship between sleep hygiene and sleep problems in adolescents referred for Behavioral Sleep Medicine (BSM) treatment.

METHODS

Clinical participants included BSM patients aged 11-18 years (n = 354) with insomnia. Adolescents completed the Adolescent Sleep Hygiene Scale (ASHS) and the Pediatric Insomnia Severity Index. Caregivers completed the Sleep Disorders Inventory for Students. Independent samples t-tests compared sleep hygiene between our clinical sample and the community-based ASHS validation sample (572 American adolescents). We report which sleep hygiene subscales fell below thresholds indicating clinically significant problems. Multiple linear regressions determined whether demographics and sleep hygiene subscales predicted sleep problems.

RESULTS

Adolescents referred to our BSM clinic had better overall sleep hygiene than the community-based validation sample, p < .001. They had inadequate sleep hygiene practices related to sleep stability, behavioral arousal, and cognitive/emotional arousal. Demographics and sleep hygiene factors significantly predicted both adolescent-reported insomnia severity and caregiver-reported sleep disturbance, ps < 0.001.

CONCLUSION

Poor sleep hygiene may result from maladaptive coping and can compound existing sleep problems. It is important to have consistent definitions of sleep hygiene that limit overlap with other key intervention targets.

Prenatal and Childhood Phthalate Mixtures and Adolescent Sleep Health in the HOME Study

BACKGROUND

The biological mechanisms linking early life phthalate exposure with adverse behaviors and cardiometabolic conditions also impact sleep health, but whether early life exposure impacts adolescent sleep is unknown.

OBJECTIVES

We evaluated whether gestational and childhood urinary phthalate metabolite mixtures were associated with sleep characteristics during adolescence. We also examined periods of heightened susceptibility to individual phthalates.

METHODS

In the Health Outcomes and Measures of the Environment (HOME) Study (Cincinnati, Ohio; 2003-2006; n = 156 ), we quantified urinary metabolites of eight parent phthalate diesters during pregnancy (16- and 26-wk) and childhood (ages 1, 2, 3, 4, 5, 8, and 12 years). Using regression calibration approaches, we estimated average measurement error-corrected phthalate metabolite concentrations during pregnancy and childhood. We used wrist actigraphy to assess sleep characteristics for 1 wk among participants at age 12. Using quantile-based g-computation, we estimated covariate-adjusted differences in sleep efficiency (%), sleep fragmentation index scores (%), sleep duration (minutes) per quartile increase in all phthalate metabolite concentrations (ψ ), and weights indicating the contribution of each metabolite to ψ . Using multiple informant models, we examined whether associations between individual phthalate metabolites and sleep characteristics varied by timing of exposure.

RESULTS

Increasing all gestational phthalate metabolites by a quartile was associated with lower sleep efficiency [ψ = - 1.3 % ; 95% confidence interval (CI): - 2.4 , - 0.3 ] and higher sleep fragmentation (ψ = 1.6 % ; 95% CI: 0.3, 3.0); mono-n-butyl phthalate (MnBP) and di(2-ethylhexyl) phthalate (DEHP) metabolites contributed most to these relations. Higher childhood phthalate metabolite mixture quartiles were associated with shorter sleep duration (ψ = - 21 minutes; 95% CI: - 34 , - 9 ); monoethyl phthalate (MEP) and monocarboxyoctyl phthalate (MCOP) contributed most to this association. We found that higher DEHP metabolite concentrations during pregnancy were more strongly related to higher sleep fragmentation than childhood concentrations. In contrast, higher MEP and MnBP concentrations during childhood, but not pregnancy, were consistently associated with shorter sleep duration.

DISCUSSION

Phthalate metabolite concentrations during pregnancy and childhood were associated with poorer adolescent sleep health. https://doi.org/10.1289/EHP15221.

The sleep health composite and chronotype among children and adolescents with type 1 diabetes compared to case-control peers without diabetes

STUDY OBJECTIVES

Our objectives were to compare sleep health composite dimensions and chronotype in children and adolescents with and without type 1 diabetes (T1D) and to explore the relationship between sleep and glycemic variability in T1D.

METHODS

The study comprised 84 participants with T1D aged between 6 to 18 years and age- and sex-matched controls. The sleep health composite was measured using actigraphy, sleep diaries, and self or parental reports. Sleep disturbance was evaluated using the DSM-5 Level 2 Sleep Disorders Scale Short Form. Chronotype was determined using the Children's Chronotype Questionnaire.

RESULTS

The median total sleep health composite score for both the T1D and control groups was 3.0 (3.0-4.0) (P = .485). Sleep quality was reported as good by 89.3% of participants with T1D and 96.4% of controls (P = .072). Objective data from actigraphy indicated poor sleep quality in 56% of participants with T1D and 59.5% of controls (P = .639). Additionally, 88% of participants with T1D and 84.5% of controls had inadequate total age-appropriate sleep duration (P = .501). Among participants with T1D, those with a stable glycemic variability (coefficient of variation < 36%) had an earlier midpoint sleep (P = .008).

CONCLUSIONS

Our study indicates that there are no significant differences in the sleep health composite and chronotype between children and adolescents with and without T1D. Although most participants reported good sleep quality, objective assessments indicated poor sleep quality. These findings suggest that children and adolescents may overestimate their sleep quality.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Sleep Patterns and Chronotype in Children With and Without Type 1 Diabetes; URL: https://clinicaltrials.gov/study/NCT06318611; Identifier: NCT06318611.

CITATION

İpar N, Boran P, Barış HE, et al. The sleep health composite and chronotype among children and adolescents with type 1 diabetes compared to case-control peers without diabetes. J Clin Sleep Med. 2025;21(5):825-834.

The effect of chronotype characteristics on cardiovascular health behaviors in school-age children: A cross-sectional study

This study aimed to investigate the effect of chronotype characteristics on cardiovascular health behaviors in school-age children. This descriptive, correlational, and cross-sectional study involved 424 school-age children aged 10-12. Participants completed the Morningness-Eveningness Scale for Children (MESC) and the Cardiovascular Health Behavior Scale for Children (CHBSC). The results were analyzed using descriptive statistics and multivariate regression analysis, adhering to ethical principles throughout the study. The mean MESC and CHBSC scores for the children were 28.37 ± 5.20 and 57.04 ± 11.34, respectively. 53.8% of the children exhibited moderate cardiovascular health behaviors, while 79% had a moderate chronotype. A moderate negative correlation was observed between MESC and CHBSC scores (r = -0.39, p < 0.01), with the MESC explaining 16% of the variance in cardiovascular health behaviors. The MESC influenced cardiovascular health behaviors and its subscales nutrition, exercise, sedentary lifestyle, self-love, and stress subscales. Most school-age children display intermediate chronotype characteristics and cardiovascular health behaviors. Children with an evening chronotype demonstrated lower levels of cardiovascular health behaviors. Chronotype characteristics had the most negative impact on the sedentary lifestyle aspect of cardiovascular health behaviors. Furthermore, chronotype plays a significant role in explaining the key factors influencing cardiovascular health behaviors.

Short-term prospective and reciprocal relations between social anxiety symptoms and sleep quality among community-recruited adolescents

OBJECTIVE

Research conducted with socially anxious youth suggests that there is an increased risk for poor sleep quality; however, this link is not consistent across the few studies and there is evidence to suggest that poor sleep quality may increase the risk for elevated social anxiety symptoms. The present study investigates both prospective and reciprocal associations between levels of self-reported social anxiety and global sleep quality while also distinguishing between within-person and between-person variations in these associations.

METHOD AND MEASURES

Community-recruited adolescents from the United States (N = 71; Mage=16.04, SD = 1.08; 64.8% girls; 80.3% White) completed a battery of questionnaires across three time-points within a six-month period; each wave occurred three months apart. A random-intercepts cross-lagged panel model was used for the analysis.

RESULTS

Findings indicated a positive relation between social anxiety and poor sleep quality at both within- and between-person levels. Higher levels of social anxiety were associated with poorer sleep quality three months later, but the reverse relation was not observed.

CONCLUSIONS

These findings provide evidence supporting the link between elevated social anxiety symptoms and future sleep problems among adolescents and lay groundwork for investigation of mechanisms driving this link. Findings suggests a need to screen for and treat sleep problems in socially anxious youth.

Associations between real-life light exposure patterns and sleep behaviour in adolescents

One of the most striking changes in the regulation of sleep-wake behaviour during adolescence is circadian phase delay. Light exposure synchronises circadian rhythms, impacting sleep regulation, however, the influence of real-life light exposure on sleep variations remains less clear. We aimed to describe the sleep and light exposure patterns of high school students with comparable schedules and socio-economic backgrounds, and to evaluate whether there was any association between them, considering chronotype. We analysed five school days and two free days of actigraphy records, from 35 adolescents (24 female, mean age: 16.23 ± 0.60). The sample was described using the Sleep Regularity Index (SRI), chronotype (actigraphy MSFsc), and self-reported diurnal preference (Morning/Evening Scale). Regression models were constructed to assess the impact of light exposure (daytime and nighttime) on subsequent sleep episodes; and to confirm whether the associations could be an indirect consequence of chronotype. Despite following similar routines, the SRI varied considerably (48.25 to 88.28). There was compatibility between the actigraphy proxy for chronotype and the self-reported diurnal preference, extracted using the circadian rhythm scale for adolescents. Less light exposure during the day was associated with later sleep onset and shorter sleep duration. An increase of 100 lux in average daytime light exposure advance of 8.08 minutes in sleep onset and 7.16 min in sleep offset. When the regressions were controlled for chronotype, these associations persisted. These findings facilitate discussions regarding the behavioural aspect of the impact of real-life light exposure on sleep and its potential as a target for interventions aiming to enhance adolescents' sleep quality.

Associations between sleep habits and different impulsivity facets in adolescence

BACKGROUND

Sleep patterns change during adolescence due to physiological maturation and psychosocial factors, leading to progressively higher eveningness, sleep deprivation and social jetlag (SJL). These sleep changes are associated with impulsivity, a common behavioral trait in adolescence which can make those with developmental disabilities more vulnerable to behavioral, cognitive and clinical difficulties. However, it is unclear which aspects of sleep and what types of impulsivity are involved.

AIMS

To investigate the relationships between sleep/circadian variables and self-reported impulsivity.

METHODS AND PROCEDURES

Three sleep/circadian variables (time in bed on weekdays, eveningness and SJL) and five dissociable facets of self-reported impulsivity (UPPS-P scale) were answered by 389 healthy 9-17-year-olds (225 girls).

OUTCOMES AND RESULTS

A significant (but small) association between eveningness and a multivariate composed of the five facets of impulsivity (5 % of variance explained) was found and negative urgency was the main driver (4 %) of this relationship.

CONCLUSION AND IMPLICATIONS

Typically developing adolescents with high eveningness traits display slight difficulty controlling their behavior when in a state of negative affect. This finding deserves an in-depth investigation in youth with neurodevelopmental disabilities, who are more prone to presenting sleep/circadian changes, externalizing problems like impulsiveness and internalizing one such as mood alterations.

The relevance of morning affect, eveningness and distinctness in regard to the mental health of adolescents

Previous studies conducted in adults indicated that the distinctness, that is, the subjective feeling of fluctuations in mood and activation - was associated with health to a greater extent than were morning affect and eveningness, but few studies have examined these relationships among adolescents. A sample of 342 Spanish adolescents (11-14 years; 44.7% girls) were assessed for morning affect, eveningness, distinctness, health-related quality of life, life satisfaction, depression symptoms, sleep habits, and self-reported academic performance. The results indicated that distinctness was associated with worse health indicators. Girls reported higher scores on distinctness and depressive symptoms whereas boys reported higher scores on morning affect, life satisfaction, physical well-being and psychological well-being. The interaction between distinctness and sex indicated that girls with greater distinctness reported greater depression, lower physical and psychological well-being, and less autonomy. The interaction between morning affect and sex indicated that girls with greater morning affect reported lower peer and social support. The results obtained in this study underline the influence of distinctness on daily functioning, especially in girls, and highlight how this characteristic is related to other aspects of health. These findings suggest that the subjective feeling of fluctuations in mood and activation during the day may have a greater impact on adolescents' quality of life than do morning affect and eveningness, highlighting the importance of considering the circadian component of distinctness when designing programs to improve adolescent health.

Melatonin secretion across puberty: A systematic review and meta-analysis

BACKGROUND

Melatonin levels decrease with aging and substantially during puberty. Studies have presented distinct melatonin levels in patients with disorders related to their pubertal development compared to healthy controls. The discrepancy suggests that a decrease in melatonin concentrations seen during adolescence might be related to the physical, hormonal, and/or neuronal alterations that occur during the pubertal period. The aim of this review was to analyze the literature reporting melatonin levels in healthy children and adolescents during puberty, and to look for a potential relationship.

METHODS

The Medline and Embase databases were searched on November 28th 2024, including all articles published from 1974 to 2024. Moreover, in the studies eligible for full-text review, a "snowball" search based by backwards referencing was carried out to identify additional studies. This means going through the references of the eligible studies, to find potential other articles relevant for our review and met our inclusion criteria. Lastly, a meta-analysis on serum melatonin concentrations with increasing age and Tanner status was performed.

RESULTS

21 studies were included. 12 studies found a decrease, 5 found no difference and 3 reported an increase in melatonin levels during pubertal advancement. One study could not report secretory alterations but was eligible for inclusion in the meta-analysis. This analysis revealed that Tanner stages were significantly associated with decreasing average as well as peak concentrations of melatonin.

CONCLUSION

The simultaneous occurrence of pubertal progression and chronological aging complicates potential reasons to the decrease observed. However, possible explanations could be related to sex hormones, physical properties of puberty or light exposure. To justify these explanations research in controlled conditions along with biochemical and clinical assessment of pubertal status is needed.

Temporal Tendencies: Exploring the Impact of Chronotype Timing on Youth Depression Risk

Developmental changes in youth sleep preferences (chronotype) and pubertal development are consequential for youth risk for depression. Previous research has identified individual differences in chronotype in risk for psychopathology. However, little is known regarding how the timing of chronotype may confer risk in youth. This study addressed this gap by examining associations between chronotypal timing and symptoms of depression in youth. Community youth (N = 155; M age =12.7) completed self-report measures of chronotype, pubertal status and depression every six months for a period of one year (three assessment points). Regression analyses showed that chronotypal timing predicted change in depressive symptoms across six months (b = -0.66, p = 0.019), but not across any other timeframe. Findings suggested that youth experiencing more of a morning preference compared to same-aged peers were at increased risk for later depression across six months. Chronotypal timing continued to predict changes in symptoms of depression controlling for gender (b = -0.63, p = 0.023) and pubertal timing (b = -0.72, p = 0.012). These findings suggest that chronotypal timing is prospectively related to changes in youth symptoms of depression. Results indicate that attention to the timing of normative changes in chronotype is warranted, in addition to mean-level differences.

Trait mindfulness in adolescents with and without Attention-Deficit/Hyperactivity Disorder

BACKGROUND AND OBJECTIVES

Mindfulness-based interventions (MBIs) are proposed to cultivate trait mindfulness through mindfulness practice, which may in turn to lead improved clinical outcomes. Individuals who report lower levels of this trait may be promising candidates for MBIs because they present with the opportunity for growth in this area. Attention-Deficit/Hyperactivity Disorder (ADHD) has been associated with low trait mindfulness, though facets of trait mindfulness and ADHD features beyond core symptoms have not been examined among youth with the disorder. The goal of this study was to examine trait mindfulness-including facets of trait mindfulness-in adolescents with and without ADHD in relation to ADHD symptoms and related ADHD characteristics.

METHODS

Adolescents (29 ADHD, 30 non-ADHD) and their caregivers completed measures of ADHD symptoms and related characteristics. Adolescents completed a trait mindfulness measure.

RESULTS

The ADHD group scored significantly lower than the non-ADHD group in trait mindfulness. ADHD symptoms and multiple related characteristics were also inversely associated with trait mindfulness. A series of regressions controlling for sex and age indicated that trait mindfulness-particularly acting with awareness-is inversely associated with ADHD symptoms, cognitive disengagement syndrome symptoms, executive functioning, and sleep.

CONCLUSIONS

Trait mindfulness, particularly acting with awareness, is lower among adolescents with ADHD and is inversely associated with ADHD and related characteristics. Because mindfulness is thought to be particularly therapeutic for those low in trait mindfulness, findings indicate the need to develop MBIs for adolescents with ADHD.

Factor structure of the Brazilian version of the Morningness-Eveningness Scale for Children (MESC) for chronotype assessment in adolescents

To translate and adapt the Morningness-Eveningness Scale for Children into Brazilian Portuguese, translation, back-translation, technical review, expert evaluation, focus group, test-retest, and factorial structure of the instrument were performed. The total sample consisted of 676 students from the 6th to 9th grade of elementary school and from the 1st to 3rd year of high school, aged between 10 and 19 years, 343 girls (51%) and 333 boys (49%), with a mean age of 13.98 (2.00) years. Of these, 40 students from the 6th grade, aged between 10 and 13 years, participated in the test-retest, 24 girls (60%) and 16 boys (40%), with a mean age of 11.17 (0.50) years. Descriptive and inferential analyses were performed, including exploratory and confirmatory factor analyses. High levels of internal consistency (α = 0.742) and test-retest (0.974) were obtained, in addition to high values for clarity of language (0.88), practical relevance (1.00) and theoretical relevance (1.00). In the confirmatory factor analysis, the model presented satisfactory validity indices: χ2 = 40.811 (df = 34), p = 0.196, RMSEA = 0.025 (90% CI: <0.001-0.049), CFI = 0.990 and TLI = 0.987, with no need for adjustments between the covariances between the items. Therefore, the MESC-BR was considered an adequate instrument to assess circadian preferences in Brazilian adolescents, given its test-retest psychometric properties and construct validity.

Transdiagnostic Sleep and Circadian Intervention in Youth: Long-Term Follow-Up of a Randomized Controlled Trial

OBJECTIVE

This preregistered study compared the effects of the Transdiagnostic Sleep and Circadian Intervention (TranS-C) with psychoeducation (PE) about sleep, health, yoga, meditation, and outdoor appreciation activities on sleep and circadian functioning, health risk, and sleep health behaviors at long-term follow-up (LTFU), an average of 8 years following treatment. We also examined if more sleep health behaviors at LTFU were associated with better sleep and circadian functioning at LTFU and if better sleep and circadian functioning were associated with lower health risk at LTFU.

METHOD

At baseline, we randomly assigned adolescents with an eveningness chronotype to TranS-C (n = 89) or PE (n = 87). Of this sample, we assessed 106 young adults (mean age at follow-up = 22.5 years; n = 55 from TranS-C; n = 51 from PE) an average of 8 years following treatment.

RESULTS

Despite TranS-C (vs PE) sustaining improvement in circadian functioning through 12-month follow-up, at LTFU, there were no significant differences between the conditions on any outcome, including sleep and circadian functioning, risks in 5 health domains indexed by self-report and ecological momentary assessment, sleep health behaviors, and physical measurements. Across both conditions, measures indicating poorer sleep and circadian functioning were associated with higher health risk across multiple domains, and more sleep health behaviors were associated with lower levels of eveningness at LTFU.

CONCLUSION

These results provide an important window into the influence of development on long-term outcomes for youth and raise the possibility that interventions for youth could be enhanced with a focus on habit formation.

PLAIN LANGUAGE SUMMARY

This study evaluated the effects of a psychological treatment (the Transdiagnostic Sleep and Circadian Intervention [TranS-C]), relative to a psychoeducation active control (PE) at 8 years following treatment, on sleep problems, the preference and tendency for later bedtimes and health risk (ie, risk for worse health). Across both groups combined, the study also examined whether more sleep health behaviors are related to better sleep and whether better sleep is related to lower health risk. At long-term follow-up, there were no differences between TranS-C and PE on any outcome. However, overall poorer sleep was related to greater health risk, and those who engaged in better sleep habits tended to have an earlier "feeling best" sleep rhythm at long-term follow-up. Given evidence that youth tend to outgrow their preference and tendency for later bedtimes with age, our findings shed light on the potential impact of development on long-term outcomes for youth and raise the question of whether treatments for youth could be improved with evidence-based tools for promoting habit formation of positive sleep behaviors.

CLINICAL TRIAL REGISTRATION INFORMATION

Maintaining Behavior Change: A 6-Year Follow-up of Adolescent 'Night-owls'; https://www.

CLINICALTRIALS

gov/; NCT05098782.

STUDY PREREGISTRATION INFORMATION

Long-term Follow-up of Young Adults Who Received TranS-C to Modify Eveningness Chronotype in Adolescence; https://osf.io/; d5a4g.

DIVERSITY & INCLUSION STATEMENT

We worked to ensure race, ethnic, and/or other types of diversity in the recruitment of human participants. We worked to ensure that the study questionnaires were prepared in an inclusive way. We worked to ensure sex and gender balance in the recruitment of human participants. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented racial and/or ethnic groups in science. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented sexual and/or gender groups in science. One or more of the authors of this paper self-identifies as living with a disability. One or more of the authors of this paper received support from a program designed to increase minority representation in science.

Impaired sleep-dependent memory consolidation in pediatric narcolepsy type 1

STUDY OBJECTIVES

Disrupted nighttime sleep is common in pediatric narcolepsy type 1, yet its cognitive impact is unknown. As N2 sleep spindles are necessary for sleep-dependent memory consolidation, we hypothesized that narcolepsy type 1 impairs memory consolidation via N2 sleep fragmentation and N2 sleep spindle alterations.

METHODS

We trained 28 pediatric narcolepsy type 1 participants and 27 healthy controls (HCs) on a spatial declarative memory task before a nocturnal in-lab polysomnogram and then gave them a cued recall test upon awakening in the morning. We extracted wake and sleep stage bout numbers and N2 spindle characteristics from the polysomnogram and conducted mixed model analysis of sleep-dependent memory consolidation to identify group differences.

RESULTS

Narcolepsy type 1 participants had shorter N2 bout durations and associated shorter N2 spindles versus HC, but other N2 spindle features were similar. Narcolepsy type 1 participants had worse memory performance postsleep than HCs after adjusting for age and gender (mean memory consolidation HC: -3.1% ± 18.7, NT1: -15.6 ± 24.8, main effect group × time of testing F = 5.3, p = .03). We did not find significant relationships between sleep-dependent memory consolidation and N2 spindle characteristics. Notably, increased N1% was associated with worse sleep-dependent memory consolidation with results driven by the narcolepsy type 1 group.

CONCLUSIONS

Sleep-dependent memory consolidation is mildly impaired in youth with narcolepsy type 1 and findings may be attributed to increases in N1 sleep. Further studies are needed to determine if these findings are generalizable and reversible with sleep-based therapies.

Sex Differences in Circadian Timing and Biological Night in Adolescents

Circadian rhythms, intrinsic 24-h cycles that drive rhythmic changes in behavior and physiology, are important for normal physiology and health. Previous work in adults has identified sex differences in circadian rhythms of melatonin, temperature, and the intrinsic period of the human circadian timing system. However, less is known about sex differences in circadian rhythms at other developmental stages. To address this gap, we considered a secondary analysis of sleep and circadian data from two studies involving adolescent participants during the academic year: (n = 32, 15 females). We collected 1 week of in-home actigraphy data to calculate sleep-wake parameters and in-laboratory salivary melatonin data collection in dim-light conditions was used to compute dim-light melatonin onset (DLMO) and offset (DLMOff) using a threshold of 4 pg/mL. We found that DLMO was an average of 96 min earlier, the time between DLMO and bedtime was an average of 56 min greater, and the biological night (time between DLMO and DLMOff) was 60 min longer in females compared to males, even though bedtimes and waketimes were not statistically different between the groups. In addition, after accounting for differences in bedtime, sex was still a significant predictor of DLMO. Conversely, no evidence was found indicating a difference in DLMOff or the phase angle between DLMOff and waketime by sex. These findings suggest that sex differences in circadian rhythms are present in adolescents and may have implications for circadian health during this important developmental period.

Sleep and circadian disturbances in children with neurodevelopmental disorders

Sleep is essential for brain development and overall health, particularly in children with neurodevelopmental disorders (NDDs). Sleep disruptions can considerably impact brain structure and function, leading to dysfunction of neurotransmitter systems, metabolism, hormonal balance and inflammatory processes, potentially contributing to the pathophysiology of NDDs. This Review examines the prevalence, types and mechanisms of sleep disturbances in children with NDDs, including autism spectrum disorder, attention-deficit hyperactivity disorder and various genetic syndromes. Common sleep disorders in these populations include insomnia, hypersomnia, circadian rhythm disorders, sleep-related breathing disorders and parasomnias, with underlying factors often involving genetic, neurobiological, environmental and neurophysiological influences. Sleep problems such as insomnia, night awakenings and sleep fragmentation are closely linked to both internalizing symptoms such as anxiety and depression, and externalizing behaviours such as hyperactivity and aggression. Assessment of sleep in children with NDDs presents unique challenges owing to communication difficulties, comorbid conditions and altered sensory processing. The Review underscores the importance of further research to unravel the complex interactions between sleep and neurodevelopment, advocating for longitudinal studies and the identification of predictive biomarkers. Understanding and addressing sleep disturbances in NDDs is crucial for improving developmental outcomes and the overall quality of life for affected individuals and their families.

Sleep Physiology and Neurocognition Among Adolescents With Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Few studies have characterized the nature of sleep problems among adolescents with attention-deficit/hyperactivity disorder (ADHD) using polysomnography (PSG). Additionally, although adolescents with ADHD and adolescents with sleep disturbances display similar neurocognitive deficits, the role of sleep in contributing to neurocognitive impairment in adolescent ADHD is unknown. This study investigated differences in PSG-measured sleep among adolescents with ADHD compared with non-psychiatric controls and associations with neurocognition.

METHOD

Medication-free adolescents aged 13 to 17 (N = 62, n = 31 with ADHD; mean age = 15.3 years; 50% female) completed a diagnostic evaluation, 3 nights of ambulatory PSG, the Cambridge Neuropsychological Test Automated Battery, and subjective reports of sleep and executive functioning. Linear regressions covarying for age, sex, and pubertal status examined group differences in sleep indices, and partial Pearson correlations assessed relations between sleep and neurocognition.

RESULTS

Although adolescents with ADHD did not exhibit differences in PSG-measured sleep duration, awakenings, or latency (ps > .05) compared with non-psychiatric controls, they displayed lower slow wave sleep percentage (β = -.40) and non-rapid eye movement (NREM) electroencephalogram (EEG) delta power (β = -.29). They also exhibited greater stage 2 percentage (β = .41), NREM EEG sigma power (β = .41), and elevated self-reported sleep disturbances (ps < .05). Lower NREM EEG delta power, increased high-frequency power, and slower decline in NREM EEG delta power overnight were associated with poorer neurocognition among adolescents with ADHD.

CONCLUSION

Adolescents with ADHD reported more sleep disturbances than non-psychiatric controls and exhibited differences in sleep stage distribution and NREM sleep EEG frequency. Sleep-EEG spectral indices were associated with impaired neurocognition, suggesting that physiological sleep processes may underlie neurocognitive deficits in ADHD. Future studies may clarify whether sleep plays a causal role in neurocognitive impairments in adolescent ADHD and whether interventions normalizing sleep improve neurocognition.

PLAIN LANGUAGE SUMMARY

This study investigated the sleep physiology in a sample of 62 adolescents, 31 with attention-deficit/hyperactivity disorder (ADHD) and 31 with no psychiatric diagnoses, aged 13 to 17. The authors found that medication-free adolescents with ADHD displayed reduced time in deep slow wave sleep, and increased time in lighter stage 2 sleep, than adolescents without a psychiatric diagnosis. Results indicate that disruptions in the amount and pattern of slow wave electroencephalogram (EEG) activity, as well as increased high frequency EEG power during sleep, were associated with lower cognitive performance among adolescents with ADHD. The study findings suggest that sleep physiology may contribute to cognitive deficits in ADHD and future research should assess whether interventions normalizing sleep improve cognitive performance in adolescents with ADHD.

CLINICAL TRIAL REGISTRATION INFORMATION

Sleep Dysfunction and Neurocognitive Outcomes in Adolescent ADHD; https://clinicaltrials.gov/; NCT02897362.

DIVERSITY & INCLUSION STATEMENT

We worked to ensure sex and gender balance in the recruitment of human participants. We worked to ensure race, ethnic, and/or other types of diversity in the recruitment of human participants. We worked to ensure that the study questionnaires were prepared in an inclusive way. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented sexual and/or gender groups in science. We actively worked to promote sex and gender balance in our author group. While citing references scientifically relevant for this work, we also actively worked to promote sex and gender balance in our reference list.

Advancing adolescent bedtime by motivational interviewing and text message: a randomized controlled trial

BACKGROUND

Sleep deprivation is a prevalent problem among adolescents which is closely related to various adverse outcomes. The lack of efficacy of current sleep education programs among adolescents argues for the need to refine the content and format of the intervention. This study aimed to evaluate the effectiveness of a group-based sleep intervention using motivational interviewing plus text reminders in changing adolescent sleep habits.

METHODS

This study is a randomized controlled trial comparing motivational group-based sleep intervention with nonactive control group. The primary outcomes were the sleep-wake patterns measured by both sleep diary and actigraphy at postintervention, 3 and 6 months after the intervention. The trial was registered with the Clinical Trial Registry (NCT03614572).

RESULTS

A total of 203 adolescents with school day sleep duration of <7 hr (mean age: 15.9 ± 1.0 years; males: 39.9%) were included in the final analysis. Sleep diary and actigraphy data both showed that adolescents in the intervention group had earlier weekday bedtime at postintervention (sleep diary: estimated mean difference: 33.55 min, p = .002; actigraphy: 33.02 min, p = .009) and later wake-up time at 3-month follow-up compared to the control group (sleep diary: -28.85 min, p = .003; actigraphy: -30.03 min, p = .01), and the changes in diary measured weekday bedtime were sustained up to 6-month follow-up. In addition, adolescents in the intervention group had longer sleep diary reported weekday sleep duration at 3- (35.26 min, p = .003) and 6-month follow-up (28.32 min, p = .03) than the controls. Adolescents in the intervention group also reported improved daytime alertness postintervention, which was maintained at the 6-month follow-up.

CONCLUSIONS

The motivational group-based sleep intervention is effective in advancing bedtime with improved sleep duration and daytime alertness in sleep-deprived adolescents.

Efficacy of brief behavioral and sleep hygiene education with mindfulness intervention on sleep, social jetlag and mental health in adolescence: a pilot study

OBJECTIVES

Sleep is often compromised in adolescents, affecting their health and quality of life. This pilot-study was conducted to evaluate if implementing brief-behavioral and sleep-hygiene education with mindfulness intervention may positively affect sleep-health in adolescents.

METHOD

Participants in this community-based non-randomized cohort-study volunteered for intervention (IG)- or control-group (CG). Sleep was recorded during regular school-schedule for 3-school-nights and 2-non-school-nights with an FDA-cleared/EU-Medical Device Regulation (CE-2862) compliant home sleep test, and Questionnaires were utilized to evaluate chronotype, sleepiness, insomnia-, anxiety- and depression-symptoms. The four-week intervention included sleep-hygiene education, mindfulness- and breathing-practices for one-hour, twice weekly. Data was collected during the last-week of February and first two-weeks of March 2023 and repeated after intervention.

RESULTS

Fifty-five participants completed the study, IG (86%) and CG (77%). Average age was 17.3-years and prevalence of severe social-jetlag (SJL) 72%. Participants who quit participation (n = 10) after baseline data-collection all females (3-IG/7-CG) in comparison to participants who completed the study were sleepier than the IG and CG (+ 2.6-p = 0.04; + 3.8-p = 0.001), with more symptoms of insomnia- (+ 3.8-p = 0.002; + 4.7-p < 0.0001), and depression (+ 16.7-p < 0.0001; + 19.6-p < 0.0001), and report being later-chronotypes, (-18.2, p < 0.0001;-13.1, p < 0.0001). On average the IG advanced sleep-onset (32-min; p = 0.030), decreased SJL (37-min; p = 0.011) and increased total sleep time (TST, 29-min; p = 0.088) compared to the CG. Average sleep duration did not differ significantly comparing IG and CG after intervention. Stratifying participants with severe SJL (> 2-h) at baseline; 1) responders (61%) advanced sleep-onset on non-school-nights (96-min) and decreased SJL (103-min; p < 0.001) 2) non-responders (39%) increased sleep-duration on school-nights (36-min) and non-school-nights (63-min) but maintained severe-SJL.

CONCLUSION

Teacher-lead sleep-education and mindfulness program can improve TST and SJL in adolescence.

Validation of the Morningness-Eveningness Scale for Children (MESC) with ambulatory circadian monitoring of temperature, light exposure and activity

The external validity of the Morningness-Eveningness Scale for Children was analysed via objective measures of skin temperature, light exposure and motor activity with the ambulatory circadian monitoring methodology. A total of 138 adolescents (57 boys and 81 girls) aged 12-13 years, who in addition to completing the Morningness-Eveningness Scale for Children to determine their circadian typology wore a wrist activity device (Kronowise 3.0; Kronohealth SL) during school days and a weekend, participated. Circadian parameters, such as mesor, amplitude and acrophase, were estimated for skin temperature, light exposure and motor activity, as were sleep parameters, such as risetime, bedtime and social jetlag. The results indicated that during the weekend E-type adolescents experienced later acrophases in temperature, light and activity than I-type and M-type adolescents did, whereas boys experienced earlier acrophases in temperature and activity. When school weekdays were compared with the weekend, there was a weekend delay in the acrophases of temperature (1:03), light exposure (2:03) and activity (3:15). The results obtained in this study provide external validity for applying the Morningness-Eveningness Scale for Children in the naturalistic context of high school while considering sex and type-of-day differences as important variables in chronopsychological studies.

Examining sex differences in morningness-eveningness and inter-individual variability across years of age: A cross-sectional study

This study investigated the impact of age on morningness-eveningness (ME) and its inter-individual variability, with a focus on sex-specific patterns. A sample of 2890 participants aged 12-94 years (55.85% female) completed the Composite Scale of Morningness. Multiple linear regression analyses revealed a significant Age × Sex interaction, indicating distinct age-dependent patterns for males and females in both ME and its inter-individual variability. We conducted segmented regression analyses to explore these dynamics further and identify breakpoints. Eveningness increased across adolescence, with both males and females reaching peak lateness at 20 years. Morningness increased thereafter until 64.94 years for females and until 59 years for males. Following these sex-specific breakpoints, morningness remained constant for females and increased at a reduced rate for males. After the age of 48, males exhibited greater morningness than females. Inter-individual variability in ME (VME) changed with age, increasing until 33 years for men and 36.80 years for women, followed by a decrease for both sexes. From 50.30 years onward, females showed greater VME compared to men. This study suggests that ME and VME shift across age, and differences between sexes were observed from middle age onwards. Diurnal preferences are likely influenced by internal and environmental variables.

Concussion history is associated with poor sleep quality in adolescent athletes: a cross-sectional study

STUDY OBJECTIVES

Whereas previous research has primarily focused on the immediate effects of concussion within the first year postinjury, this study examines the persistent effects of concussion on subsequent sleep quality in adolescent soccer players.

METHODS

This study used a cross-sectional design, recruiting a convenience sample of adolescent athletes from US Youth Soccer camps. Participants completed a self-reported questionnaire including the Pittsburgh Sleep Quality Index to assess their sleep quality. Athletes were also asked to report sport participation information, any past occurrence of concussion or knee injury, and any sport-related injury in the past 12 months. Independent samples t tests were performed to identify significant differences in Pittsburgh Sleep Quality Index scores between injured and noninjured participants.

RESULTS

A total of 177 participants (103 male, 14.61 ± 1.88 years of age) were included in the analysis. The concussion injury group exhibited later bedtimes (difference: 0.32 ± 0.05 hours, P = .047), fewer hours of sleep (difference: 0.56 ± 0.11 hours, P = .015), and more frequent sleep disturbances (P = .012). Furthermore, these athletes reported lengthened sleep latency (difference: 2.55 ± 3.36 minutes, P = .016) and higher levels of daytime dysfunction (P = .041) following their concussion injuries. Moreover, athletes in the concussion injury group displayed worse sleep quality scores (difference: 0.42 ± 0.06, P < .001) and higher total Pittsburgh Sleep Quality Index scores (difference: 1.91 ± 0.41, P < .001). No significant differences were found based on past knee injury or sport-related injury in the past 12 months.

CONCLUSIONS

These findings suggest the need for targeted interventions aimed at improving sleep quality in adolescent athletes with a history of concussion.

CITATION

Sahin S, Erdman AL, Loewen A, et al. Concussion history is associated with poor sleep quality in adolescent athletes: a cross-sectional study. J Clin Sleep Med. 2025;21(1):129-135.

Reliability and validity of the Persian version of the Children's Chronotype Questionnaire in school and preschool-aged children (CCTQIR)

Chronotype refers to individual differences in the circadian phase that affect a person's biological and psychological functioning. One of the most useful tools for measuring chronotype in children aged 4 - 11 years is the Children's Chronotype Questionnaire (CCTQ). Therefore, due to the importance of measuring chronotype in children and also the lack of a standard scale in Iran, this study aimed to examine the reliability and validity of the Persian version of this questionnaire for children. The participants of this cross-sectional study were 272 Iranian children aged five to eleven years with their parents, selected by convenience sampling method. To collect data, all participants completed the CCTQ and the Children's Sleep Habits Questionnaire (CSHQ), which were examined by the researchers for their construct and concurrent validity. Over a period of three weeks, 50 mothers participated in a test of the test-retest reliability of the CCTQ. During this time, their sleep patterns were monitored using a sleep diary to test for reliability. The Cronbach's alpha of the CCTQ-M/E was 0.71. Test-retest reliability using the Spearman correlation coefficient between two observations with an interval of three weeks was 0.83. The MSFsc index was significantly correlated with M/E, CT, and most of the parent-reported sleep/wake parameters. In addition, the three indicators of the CCTQ were significantly associated with most of the sleep/wake parameters of the sleep diary and the components of the CSHQ. The Persian version of the CCTQ has desirable psychometric properties for the assessment of chronotype in five- to eleven-year-old children.

Anxiety in emerging adults: The role of chronotype, emotional competence, and sleep quality

Anxiety is being increasingly linked to circadian rhythms, including chronotype, in addition to its intricate links with sleep quality. Emotional competence is thought to be a strong predictor of wellbeing and mental health. This study aimed to examine whether a combination of chronotype, sleep quality, and intrapersonal emotional competence can predict anxiety in emerging adults (aged 18-29), who have the greatest prevalence of adult anxiety. One hundred and seventeen participants completed self-report measures of chronotype, sleep quality, emotional competence, and anxiety. A multiple linear regression, with anxiety as the criterion variable, showed that while all predictors were significant, sleep quality was the strongest predictor of anxiety. A later chronotype, poorer sleep quality and lower intrapersonal emotional competence were related to higher anxiety. Thus, integrating intrapersonal emotional competence and chronotype considerations into interventions may address the interplay between sleep quality and anxiety in emerging adults more effectively.

Integrating habit science and learning theory to promote maintenance of behavior change: does adding text messages to a habit-based sleep health intervention (HABITs) improve outcomes for eveningness chronotype young adults? Study protocol for a randomized controlled trial

BACKGROUND

Eveningness chronotype-the tendency for later sleep and wake times-arises from a confluence of psychosocial, behavioral, and biological factors. With the onset and progression of puberty, many young people develop an eveningness chronotype, which remains prevalent through the transition into adulthood. Eveningness has been associated with increased risk for poorer health. While eveningness is modifiable, maintaining the necessary behavior changes can be challenging. The science on habits demonstrates that habit formation is a key mechanism for maintaining behavior change over time. Learning theory offers schedules of reinforcement that also hold promise for enhancing the maintenance of behavior change. The present study will evaluate the Habit-based Sleep Health Intervention (HABITs)-which combines the Transdiagnostic Intervention for Sleep and Circadian Dysfunction (TranS-C) with the science of habits-and a text message intervention informed by learning theory to attempt to sustainably modify the contributors to eveningness among young adults (18-30 years of age).

METHODS

Participants (N = 160) will be randomly allocated to HABITs and HABITs + Texts. Both interventions include HABITs which involves three 50-min sessions followed by six 30-min sessions. Alongside the latter six sessions, HABITs + Texts will concurrently receive the text message intervention. Aims 1-3 will compare HABITs + Texts to HABITs on improvements in the outcomes of (1) utilization of sleep health behaviors and habit formation, (2) sleep and circadian functioning, and (3) functioning in five health-relevant domains, in the short (post-treatment) and longer (6-month and 12-month follow-up) term. Exploratory analysis will (1) compare HABITs and HABITs + Texts on (a) if sleep health behavior habit formation mediates the effects of intervention on improvement in outcomes and (b) if intervention effects are moderated by select variables, and (2) to evaluate if HABITs (regardless of the text message intervention) is associated with an improvement in outcomes in the short and longer term.

DISCUSSION

This study has the potential to advance knowledge on (1) the value of leveraging the science of habits and learning theory in behavior change interventions, (2) the use of a low-cost and efficient intervention for habit formation and maintenance, (3) interventions that address eveningness chronotype, and (4) processes related to behavior change during emerging adulthood.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05167695. Registered on December 22, 2021.

The relationship between chronotype video game addiction and sleep quality in school-age children: A structural equation modeling approach

This study aimed to investigate the relationship between chronotype, video game addiction, and sleep quality in school-age children using structural equation modeling. It was performed using structural equation modeling, with 545 secondary school students in northern Turkey meeting the inclusion criteria. Data were collected through face-to-face interviews utilizing the Personal Information Form, the Morningness Eveningness Scale for Children (MESC), the Video Game Addiction Scale for Children (VASC), and the Sleep Quality Scale. The findings revealed that the average video game addiction score of children was 55.22, which was associated with poor sleep quality and efficiency. Additionally, chronotype was found to mediate the relationship between video game addiction and both sleep quality (β = 0.024; p < 0.001) and sleep efficiency (β = -0.068; p < 0.001). The model was found to be close to acceptable levels for the variables according to the fit indices.

Supporting healthy sleep: a qualitative assessment of adolescents with type 1 diabetes and their parents

OBJECTIVE

Poor sleep health is common in adolescence due to a combination of physiological, psychosocial, and environmental factors. Adolescents with type 1 diabetes (T1D) may be at increased risk for poor sleep health due to physiological and behavioral aspects of diabetes and its management. This article describes a qualitative analysis of interviews with adolescents with T1D and their parents about facilitators and barriers to sleep health and family strategies to balance teens' sleep with competing demands.

METHODS

Separate interviews were conducted with 20 adolescents with T1D and 20 parents. Interviews were recorded and transcribed verbatim and analyzed thematically. Participants were on average 15.8 ± 1.2 years old, 45% female, and 85% non-Hispanic White.

RESULTS

Overnight diabetes management was the most frequently reported barrier to sleep. Families reported different strategies for taking responsibility of overnight diabetes management, which differentially impacted sleep. Families worked to balance diabetes management and sleep with other aspects of adolescent life, including school demands, social activities, and electronics use. Facilitators to healthy sleep identified by families included diabetes assistive technology and maintaining a consistent sleep/wake schedule. Both adolescents and parents voiced beliefs that their diabetes care team is not able to help with sleep health.

CONCLUSIONS

Pediatric psychologists should be aware of the specific sleep barriers experienced by adolescents with T1D and their parents. A focus on overnight diabetes management strategies may facilitate psychologists' support of families in the adolescent's transition to independent diabetes management. Research is needed on the impact of optimizing sleep health in adolescents with T1D.

The interplay among sleep patterns, social habits, and environmental cues: insights from the Spanish population and implications for aligning daily rhythms

Introduction

The interplay among sleep patterns, social habits and environmental cues is becoming increasingly more important for public health and wellbeing due to its connection to circadian desynchronization. This paper explores said connections in Spain (which has an official and solar time mismatch), introducing the "Three Times Score" ‒which is based on questions widely used in the field‒ as a complementary tool for exploring the interplay of daily rhythms.

Methods

The questionnaire covers sleep-related habits, social time, and environmental time. The study includes 9,947 participants (34.89 ± 12.15 y/o, mean ± SD; 5,561 women) from different Spanish regions. Sleep parameters were obtained for work and free days, as well as a modified version of the sleep-corrected midsleep on free days (MBFbc) and a parameter similar to social jet lag, both derived from bed time rather than sleep time. A number of indexes were computed to compare bed and work-related habits, together with natural light/dark cycle, along with the Three Times Score. Mixed-effect regression analysis was used to test whether the biological, social and environmental factors included in the study significantly predicted the sleep-related parameters: bedtime, wake-up time, time in bed and mid-bedtime.

Results and discussion

Temporal differences were found between work and free days, with waking-up occurring 2 h earlier on work days (7:10 ± 0:01) than on free days (9:15 ± 0:01). Bed times were 1 h earlier on work days (23:46 ± 0:01) than on free days (00:45 ± 0:01), whereas time in bed was over 1 h shorter on work (7 h 23 min) versus free (8 h 29 min) days. Strong correlations were found between work starting time and waking-up and bedtimes on workdays. Women went to bed earlier and woke up later, spending more time in bed. Differences in sleep habits were observed between work and free days across all age groups. The group of younger adults (18-30) reported going to bed later than older and younger groups, especially on free days. Adolescents and young adults also woke-up later than other age groups, especially on free days. Social jet lag (relative to bed time) and desynchronization indexes also varied with age, with younger adult participants exhibiting higher levels. Seasonal differences were limited, with minor variations between winter and summer. According to the multiple regression analysis, social (day type, work start time, alarm clock usage), biological (age, gender, in most cases related to sex) and environmental (sunset time) factors significantly contribute to predicting sleep/bed related schedules. This study provides insights into sleep habits in the Spanish population, introducing the Three Times Score as a complementary tool for exploring the interactions between sleep/bed-related habits, natural darkness and work-related schedules. Understanding this interplay is crucial for developing tailored interventions to improve sleep and wellbeing.

New Insights into Health Conditions Related to Malfunctions in Clock Genes

Chronotypes play a crucial role in regulating sleep-wake cycles and overall health. The aim of this study was to investigate chronotype, sleep quality, polymorphisms of clock genes and the level of leptin in serum. We used standardized questionnaires to assess chronotype and sleep quality. Genetic analysis was performed to determine the selected clock gene polymorphism. Serum leptin level was measured by the Elisa method. The results showed that serum leptin concentration was elevated in women, as well as in men who had a high waist-to-hip ratio (WHR) and body mass index (BMI). The evidence indicated that younger students (<22 years old) were most likely to experience poor sleep quality. Nevertheless, our multivariate analysis revealed that young age and a morning-oriented chronotype were associated with better sleep quality. We noted that clock gene polymorphisms were present in 28.6% of the participants. Moreover, polymorphisms of PER1 c.2247C>T (rs2735611) and PER2 c.-12C>G (rs2304672) genes were associated with serum leptin level and chronotype, respectively. These findings provide insights into the relationships between chronotype, sleep quality, clock gene polymorphisms and obesity risk in biomedical students. Understanding these factors can contribute to better sleep management and potential interventions to improve health outcomes in humans.

The relationship between chronotype and mental toughness in adolescents: Is resilience a mediator?

OBJECTIVE

This study was designed to examine the mediator role of resilience in the relationship between chronotype and mental toughness in adolescents.

METHODS

The descriptive correlational study was completed with 342 high school students from one school in Türkiye (mean age 17.25±1.11 years). Data were collected with the Morningness-Eveningness Scale for Children, Child and Youth Resilience Measure, and Mental Toughness Scale for Adolescents. Hierarchical regression analyses with PROCESS Model 4 were used to evaluate the mediator effect.

RESULTS

It was observed that the morning chronotype tendency increased resilience (p < 0.001) mental toughness (p < 0.001). Higher resilience led to increased mental toughness. When the mediation effect was examined, resilience was a full mediator in the relationship between chronotype characteristics and mental toughness (β=0.396; p = 0.000).

CONCLUSIONS

According to these results, a morning chronotype tendency in adolescents increases their resilience and, therefore, mental toughness. These results suggest that effective methods for enhancing mental toughness in adolescents should be multifaceted. Additionally, it highlights the importance of identifying and regulating chronotype tendencies among adolescents, while also emphasizing the need to increase resilience in this demographic.

Determination of chronotype at preschoolers: psychometric properties of the Turkish adaptation of the Morningness/Eveningness Scale (Parent Report Form)

The aim of this study is to examine the psychometric properties of the Turkish adaptation of the Morningness/Eveningness Scale (M/E Scale-Parent Report Form) family evaluation form for preschool children. The study sample consisted of 276 parents with children aged 4-6 years. The study calculated Cronbach's alpha internal consistency coefficient and corrected item-total correlations of the scale. It also determined the scale's distinctiveness, stability analyses, and convergent validity. The Turkish version of the M/E Scale (Parent Report Form), consisting of 10 items, is unidimensional. The Cronbach's alpha internal consistency coefficient of the scale was 0.80 and the corrected item-total correlation values varied between 0.51 and 0.76. There was a positive correlation at the level of 0.75 between the applications of the scale with two-week intervals and at the level of 0.63 between the single-item chronotype scale within the scope of convergent validity and the M/E Scale (Parent Report Form). This study determined a low correlation between the child's chronotype and the father's chronotype, and a moderate correlation with the mother's chronotype. The Turkish M/E Scale (Parent Report Form) was found to be valid and reliable. This scale is a short and easy-to-use measurement tool for determining the chronotypes of 4-6-year-old children.

Puberty interacts with sleep and brain network organization to predict mental health

Introduction

Along with pubertal development, the transition to adolescence brings about increased risk for sleep disturbances and mental health problems. Functional connectivity of overlapping large-scale brain networks, such as increased connectivity between the default mode and dorsal attention networks, has been reported to relate to both sleep and mental health problems. Clarifying whether pubertal development interacts with sleep disturbances and functional brain networks to predict mental health may provide information to improve the timing and design of interventions targeting sleep disturbances in adolescents.

Methods

To examine how pubertal status and tempo relate to sleep disturbances and shape the relationship between sleep disturbances and mental health problems, we harnessed a large sample of children aged 10-14 years from the Adolescent Brain and Cognitive Development (ABCD) Study (N ~ 3,000-10,000). We used graph theoretical tools to probe how pubertal development concurrently interacts with sleep disturbances and brain network organization to predict mental health problems.

Results

We found that advanced pubertal status, but not pubertal tempo, predicted sleep disturbances; however, both pubertal status and tempo interact with sleep disturbances to predict mental health problems and engage in three-way interactions with sleep and brain network organization to predict mental health problems.

Discussion

Overall, this work suggests that less advanced pubertal status and slower tempo are risk factors for the strongest links between sleep disturbances, brain organization, and mental health problems. Further, our findings speak to the importance of accounting for interactions in the constellation of factors that surround complex behavioral and clinical syndromes, here internalizing and externalizing disorders, and provide new context to consider for targeted interventions.

Racial/Ethnic Differences in the Age-Varying Association Between Adherence to 8-5-2-1-0 Guidelines in Adolescents with High BMI

PURPOSE

To examine the association between adherence to sleep, dietary, screen time, and physical activity (PA) (8-5-2-1-0) guidelines and risk of high body mass index (BMI ≥ 85 percentile) among U.S. adolescents and to assess for racial inequities and age-varying effects in these associations.

METHODS

Data from the 2019 Youth Risk Behavior Surveillance System survey were used to conduct multivariable logistic regression models and moderation analysis by race/ethnicity and age using time-varying varying effect models (TVEM) and estimate associations of interest.

RESULTS

Of the 13,518 adolescents aged ≥ 14 years, only 0.5% met all guidelines. Adolescents adhering to sleep guidelines had a 21% reduction in their odds of having a high BMI (OR 0.79, 95% CI 0.67-0.93). Those adhering to PA guidelines had a 34% reduction in their odds of having a high BMI (OR 0.66, 95% CI 0.56-0.79), and those adhering to screen time guidelines had a 17% reduction in their odds of having a high BMI (OR 0.83, 95% CI 0.72-0.95). TVEM showed associations between adherence to sleep and screen time guidelines with high BMI fluctuate and are at specific ages. TVEM revealed substantial racial/ethnic differences in the age-varying association between adherence to 8-5-2-1-0 guidelines and high BMI throughout adolescence.

CONCLUSIONS

Associations between adherence to sleep and screen time guidelines and high BMI fluctuate with age, highlighting the need for nuanced interventions targeting 24-h movement guidelines (sleep, PA, and screen time) across adolescence, particularly given racial/ethnic disparities.

Construction and Initial Examination of Inter-Rater Reliability of a Structured Clinical Interview for DSM-5-TR Sleep Disorders (SCISD) - Kid

STUDY OBJECTIVES

To construct and evaluate the inter-rater reliability of the Structured Clinical Interview for DSM-5-TR Sleep Disorders - Kid (SCISD-Kid).

METHOD

The SCISD-Kid was modeled on the adult SCISD-R and accounted for pediatric developmental and sociocultural factors. Fifty sleep-disturbed children (Mage = 11.9, SD = 2.9) and 50 caregivers responded to the final SCISD-Kid. Video recordings were double-scored to evaluate inter-rater reliability.

RESULTS

The final SCISD-Kid contained approximately 90 questions. Eight of the nine covered disorders had prevalence rates sufficient for analyses for both samples (i.e., k > 2). Inter-rater reliability was examined using Cohen kappa coefficients (κ); reliability estimates ranged from excellent to good. For youth, restless legs syndrome yielded the lowest reliability (.48), while nightmare disorder, narcolepsy, and NREM sleep arousal disorder - sleepwalking type showed the highest reliability (1.00). Across caregivers, NREM sleep arousal disorder - sleep terror type (.49) and hypersomnolence (.54) had the lowest reliability. In contrast, circadian rhythm - delayed sleep phase type, nightmare disorder, and NREM sleep arousal disorder - sleepwalking type showed the highest reliability (1.00).

CONCLUSIONS

The SCISD-Kid is a promising tool for screening sleep disorders. It showed good to excellent reliability across both samples. Next steps for validation will be discussed.

Improvement of Jet Lag and Travel Fatigue Symptoms and Their Association with Prior International Travel Experience in Junior Athletes

Jet lag and travel fatigue can occur after crossing multiple time zones in a short period of time, possibly affecting various aspects of an athlete's behavior. However, there are few studies regarding this issue, particularly considering junior athletes. This study aimed to investigate and quantify the symptoms of jet lag and travel fatigue and the factors impacting these conditions. A survey was completed by 41 Japanese junior athletes (21 men and 20 women), competing at an international game in Finland, to assess their performance, sleeping habits, digestion, fatigue, and jet lag on the first day of arrival and on the opening day of the competition. Although athletes awoke less often during sleep on the opening day of the competition compared with the first day, sleep time, ease of falling asleep, and sleep quality decreased significantly. Prior experience traveling abroad for international competitions was positively associated with improvements regarding ease of falling asleep (coefficient = 2.22, p = 0.01), quality of sleep (coefficient = 2.16, p = 0.02), and alertness after waking up (coefficient = 1.85, p = 0.05) by the opening day of the competition when compared with the results for athletes who had no such prior experiences. Junior athletes experience symptoms of jet lag and travel fatigue that may persist until the day of competition, and prior experience traveling abroad may help in alleviating their symptoms.

What Is the Relationship between Chronotype and Disordered Eating in Adolescents? The EHDLA Study

BACKGROUND

Evidence assessing the relationship between chronotype and disordered eating in adolescents is scarce. The current study tried to evaluate the association between chronotype and disordered eating in a sample of Spanish adolescents.

METHODS

This secondary cross-sectional study analyzed data from the Eating Healthy and Daily Life Activities (EHDLA) study. The sample consisted of 703 adolescents (56.3% girls) aged between 12 and 17 years from the Valle de Ricote (Region of Murcia, Spain). Chronotype was assessed using the Morningness/Eveningness Scale in Children (MESC). Disordered eating was evaluated by two psychologists using the Sick, Control, One, Fat, and Food (SCOFF) questionnaire.

RESULTS

Adolescents with an eveningness chronotype showed a higher SCOFF score (estimated marginal mean [M] = 1.1; 95% confidence interval [CI] 0.7 to 1.5) in comparison with adolescents with a morningness chronotype (M = 0.7; 95% CI 0.5 to 0.8) (p = 0.010), as well as with those with an intermediate chronotype (M = 0.6; 95% CI 0.5 to 0.8) (p = 0.032). A higher predictive probability of having disordered eating was identified in adolescents with an eveningness chronotype (39.5%; 95% CI 22.8% to 59.1%), compared to adolescents with an intermediate chronotype (14.9%; 95% CI 10.8% to 20.1%) (p = 0.008) and with their counterparts with a morningness chronotype (16.9%; 95% CI 11.6% to 24.0%) (p = 0.021).

CONCLUSIONS

This study reveals that adolescents with an eveningness chronotype are more likely to exhibit disordered eating behaviors compared to those with morningness or intermediate chronotypes. These findings highlight the importance of considering chronotype in adolescent health, particularly in developing targeted interventions to prevent eating disorders.

Sleep duration and social jetlag in healthy adolescents. Association with anxiety, depression, and chronotype: a pilot study

PURPOSE

Misalignment between sleep opportunity and chronotype preference during adolescence may affect sleep and mental health. The aim of this study was to objectively evaluate sleep duration and social jetlag (SJL) to observe if there is a relationship with anxiety, depression, or chronotype.

METHODS

Community based cohort study (n = 65) was conducted in Northern Europe. Participants recorded their sleep during the regular school schedule for 3 school nights and 2 free nights with FDA-cleared/EU Medical Device Directive (CE-02862) compliant home sleep test. They also completed validated questionnaires to assess (Morningness Eveningness Questionnaire; MEQ), sleepiness (Epworth Sleepiness Scale; ESS), and insomnia (Insomnia Severity Index; ISI), anxiety (General Anxiety Disorder-7; GAD-7), and depression symptoms (Beck's Depression Inventory-II; BDI-II). Data were collected during the last week of February and the first 2 weeks of March, 2023.

RESULTS

Average sleep duration on school nights was 7 h, 15 min, with 18% of participants on average sleeping ≥ 8 h. Average sleep onset was significantly later on free nights (1 hour, 47 minutes; p < 0.0001) causing a high prevalence of moderate-severe SJL, in 71% of participants. Evening chronotypes (prevalence 15.4%) fell asleep later on free nights, causing them to have significantly more SJL (2 hours, 58 minutes) than morning chronotypes (1 hour, 32 minutes) and intermediary chronotypes (1 hour, 36 minutes). Evening chronotypes also had more severe insomnia (ISI + 4.4, p = 0.006; + 4.0, p = 0.001) and greater depressive symptoms (BDI-II + 21.6, p < 0.0001; + 17.1, p < 0.0001). A significant negative correlation was observed between MEQ scores and ESS (r =  - 0.287; p = 0.001), ISI (r =  - 0.343, p < 0.0001), GAD-7 (r =  - 0.185, p < 0.0001), BDI-II (r =  - 0.501, p = 0.0001), and suicidal thoughts (r =  - 0.294, p = 0.017).

CONCLUSION

Adolescents are sleep-deprived and have a high prevalence of SJL that is positively correlated with depressive symptoms and evening chronotype. That evening chronotypes have shorter sleep duration, more severe SJL, and significantly more sleepiness and insomnia, anxiety, and depressive symptoms may indicate possible benefits in identifying this group with the aim to assist them in improving their sleep habits with potentially positive effects on mental health.

Sex Differences in Temporal Sleep Patterns, Social Jetlag, and Attention in High School Adolescents

Insufficient sleep and irregular sleep hours are common in adolescents, who experience a delayed sleep phase due to biopsychosocial changes associated with puberty, resulting in later sleep times. However, early morning class hours shorten sleep duration on weekdays. This condition is harmful to cognitive performance, which may be accentuated in girls due to a greater sleep need and less resistance to sleep deprivation. In this study, we evaluated sex differences concerning temporal sleep patterns, social jetlag, and attention in high school adolescents attending morning classes. Students ( n  = 146 - F: 73-16.1 ± 0.8 years; M: 73-16.2 ± 0.9 years) completed a Health and Sleep questionnaire, kept a sleep diary for 10 days, which incorporated a Maldonado Sleepiness Scale, and performed a Continuous Performance Task. Girls went to bed earlier and woke up on weekends, and spent more time in bed at night and in 24 h on weekdays and weekends, while they also had a greater irregularity in wake-up times ( p  < 0.05). There were no differences between sexes in terms of social jetlag, sleep debt, and sleepiness upon awakening ( p  > 0.05). Regarding attention, the girls had a longer reaction time in phasic alertness ( p  < 0.01) and a tendency to have fewer errors in selective attention ( p  = 0.06). These results persisted when controlled for sleep parameters. Therefore, we suggest that girls have a greater sleep need and less resistance to sleep deprivation, while the differences in attention performance could be due to different strategies, the girls could be making a trade, increasing reaction time in favor of better accuracy, while the boys could be prioritizing a faster response time.

Which adolescents are more likely to complete home-based sleep manipulation trials?

OBJECTIVES

Attrition and nonadherence are common concerns that can distort findings in clinical trials. This study examines the potential for systematic attrition in the largest sample to date of adolescents undergoing sleep manipulation.

METHODS

Using pooled data across two trials involving 242 adolescents, a cumulative logistic regression tested whether demographics and baseline sleep predicted study completion/adherence.

RESULTS

Race, a composite measure of socioeconomic status, and its elements (e.g., income, education) individually predicted completion/adherence. When entered concurrently into a multivariate predictive model, only socioeconomic status and study (trial A vs. B) were significant. Adolescents from households with higher socioeconomic status were more likely to complete or adhere to the protocol than those from households with lower socioeconomic status, p < .001.

CONCLUSIONS

Systematic attrition in sleep manipulation research could distort conclusions about under-resourced groups. Future sleep trials should intentionally measure systemic/structural factors and adopt strategies to recruit and retain participants from various backgrounds.

Sink or Swim? Sleep Patterns in Highly Trained Adolescent Swimmers during the In-Season Phase of Training

Objectives  The aim of this study was to investigate the sleeping patterns of highly-trained adolescent swimmers. Further objectives were to compare subjective and objective measures of sleep and to evaluate the relationship between electronic device use and sleep in this cohort. Methods  Fifteen national-level swimmers (age: 16.4 ± 1.0 years) wore wrist actigraphs while completing sleep diaries over a two-week training period. Types of nights were classified as early morning training (≤7am - EARLY), day training (>7am - DAY), and no training (REST). Information on electronic device use before bed and other sleep behaviors was collected via questionnaires. Results  Total sleep time (TST) was significantly ( p  < 0.05) shorter on nights preceding EARLY (5:53 ± 1:06 hour:min) compared with nights preceding DAY (7:40 ± 1:12 hour:min) and REST (7:59 ± 1:19 hour:min). Participants overestimated subjective TST by ∼54 minutes when compared with objectively measured TST ( p  < 0.05). Discussion  Adolescent athletes obtained a greater amount of sleep prior to later training the next day or before rest days, when compared with early morning swim training the next day. Adolescents also overestimated their sleep duration by ∼1 hour per night. There were no significant relationships between electronic device use at night and measured sleep indices.

The Impact of the Double School Shift System on Lifestyle Behaviors Among Mexican Adolescents

PURPOSE

Early school start times could adversely impact adolescent sleep duration. They could also impact other behaviors like diet and physical activity, either directly or indirectly through effects on sleep. We examined whether the double school shift system was associated with sleep, diet, and physical activity behaviors among Mexican adolescents.

METHODS

The analytic sample included 305 Mexican adolescents from a cohort study (on average 14.53 ± 1.75 years old and 51% male). Sleep and physical activity were measured with wrist actigraphy, while diet and other lifestyle behaviors were assessed with questionnaires. Regression analyses were conducted to compare lifestyle behaviors between the morning and afternoon school shifts, adjusting for potential confounders.

RESULTS

Adolescents attending the morning school shift (44%) had pronounced differences in sleep compared to those attending afternoon shift, including a 1.77-hour shorter sleep duration on weekdays (95% CI -1.55, -2.00), a 0.40-hour longer sleep duration on weekends (95% CI 0.10, 0.70), higher social jetlag (1.07 hours with a 95% CI of 0.87, 1.27), and an earlier chronotype. Morning shift students also had 0.85 hours longer sedentary time (95% CI 0.61, 1.10) and higher consumption of a meat and starchy food dietary pattern. Among boys only, morning shift was associated with a lower likelihood of smoking and higher consumption of a breakfast pattern.

DISCUSSION

Overall, attending a morning school shift was associated with shorter sleep, more social jetlag, greater sedentary time, and higher consumption of a meat and starchy diet. However, among boys, a few healthier behaviors were observed for the morning versus afternoon shift.

Subtyping at-risk adolescents for predicting response toward insomnia prevention program

BACKGROUND

Previous study has shown that a brief cognitive-behavioral prevention insomnia program could reduce 71% risk of developing insomnia among at-risk adolescents. This study aimed to evaluate the differential response to insomnia prevention in subgroups of at-risk adolescents.

METHODS

Adolescents with a family history of insomnia and subthreshold insomnia symptoms were randomly assigned to a 4-week insomnia prevention program or nonactive control group. Assessments were conducted at baseline, 1 week, and 6- and 12-month after the intervention. Baseline sleep, daytime, and mood profiles were used to determine different subgroups by using latent class analysis (LCA). Analyses were conducted based on the intention-to-treat approach.

RESULTS

LCA identified three subgroups: (a) insomnia symptoms only, (b) insomnia symptoms with daytime sleepiness and mild anxiety, and (c) insomnia symptoms with daytime sleepiness, mild anxiety, and depression. The incidence rate of insomnia disorder over the 12-month follow-up was significantly reduced for adolescents receiving intervention in subgroup 3 compared with the controls (hazard ratio [HR] = 0.37; 95% confidence interval [CI]: 0.13-0.99; p = .049) and marginally for subgroup 2 (HR = 0.14; 95% CI: 0.02-1.08; p = .059). In addition, adolescents who received intervention in subgroups 2 and 3 had a reduced risk of excessive daytime sleepiness (subgroup 2: adjusted OR [AdjOR] = 0.45, 95% CI: 0.23-0.87; subgroup 3: AdjOR = 0.32, 95% CI: 0.13-0.76) and possible anxiety (subgroup 2: AdjOR = 0.47, 95% CI: 0.27-0.82; subgroup 3: AdjOR = 0.33, 95% CI: 0.14-0.78) compared with the controls over the 12-month follow-up.

CONCLUSIONS

Adolescents at risk for insomnia can be classified into different subgroups according to their psychological profiles, which were associated with differential responses to the insomnia prevention program. These findings indicate the need for further phenotyping and subgrouping at-risk adolescents to develop personalized insomnia prevention.

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.

Effects of cognitive behavioural therapy and bright light therapy for insomnia in youths with eveningness: study protocol for a randomised controlled trial

BACKGROUND

Insomnia and eveningness are common and often comorbid conditions in youths. While cognitive behavioural therapy for insomnia (CBT-I) has been suggested as a promising intervention, it remains unclear whether it is sufficient to also address circadian issues in youths. In addition, despite that light has been shown to be effective in phase-shifting one's circadian rhythm, there has been limited data on the effects of bright light therapy and its combination with CBT-I on sleep and circadian outcomes in youths. The current protocol outlines a randomised controlled trial that examines the efficacy of CBT-I and CBT-I plus bright light therapy (BLT) in reducing insomnia severity, improving mood symptoms and daytime functioning (e.g. sleepiness, fatigue, cognitive function), and improving subjective and objective sleep and circadian measures compared to a waitlist control group.

METHODS

We will carry out a randomised controlled trial (RCT) with 150 youths aged 12-24 who meet the criteria of insomnia and eveningness. Participants will be randomised into one of three groups: CBT-I with bright light therapy, CBT-I with placebo light, and waitlist control. Six sessions of CBT-I will be delivered in a group format, while participants will be currently asked to use a portable light device for 30 min daily immediately after awakening throughout the intervention period for bright light therapy. The CBT-I with light therapy group will receive bright constant green light (506 lx) while the CBT-I with placebo light group will receive the modified light device with the LEDs emitting less than 10 lx. All participants will be assessed at baseline and post-treatment, while the two active treatment groups will be additionally followed up at 1 month and 6 months post-intervention. The primary outcome will be insomnia severity, as measured by the Insomnia Severity Index. Secondary outcomes include self-reported mood, circadian, daytime functioning, and quality of life measures, as well as sleep parameters derived from actigraphy and sleep diary and neurocognitive assessments. Objective measures of the circadian phase using dim-light melatonin onset assessment and sleep parameters using polysomnography will also be included as the secondary outcomes.

DISCUSSION

This study will be the first RCT to directly compare the effects of CBT-I and BLT in youths with insomnia and eveningness. Findings from the study will provide evidence to inform the clinical management of insomnia problems and eveningness in youths.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04256915. Registered on 5 February 2020.

Longitudinal associations of screen time, physical activity, and sleep duration with body mass index in U.S. youth

BACKGROUND

Youth use different forms of screen time (e.g., streaming, gaming) that may be related to body mass index (BMI). Screen time is non-independent from other behaviors, including physical activity and sleep duration. Statistical approaches such as isotemporal substitution or compositional data analysis (CoDA) can model associations between these non-independent behaviors and health outcomes. Few studies have examined different types of screen time, physical activity, and sleep duration simultaneously in relation to BMI.

METHODS

Data were baseline (2017-2018) and one-year follow-up (2018-2019) from the Adolescent Brain Cognitive Development Study, a multi-site study of a nationally representative sample of U.S. youth (N = 10,544, mean [SE] baseline age = 9.9 [0.03] years, 48.9% female, 45.4% non-White). Participants reported daily minutes of screen time (streaming, gaming, socializing), physical activity, and sleep. Sex-stratified models estimated the association between baseline behaviors and follow-up BMI z-score, controlling for demographic characteristics, internalizing symptoms, and BMI z-score at baseline.

RESULTS

In females, isotemporal substitution models estimated that replacing 30 min of socializing (β [95% CI] = -0.03 [-0.05, -0.002]), streaming (-0.03 [-0.05, -0.01]), or gaming (-0.03 [-0.06, -0.01]) with 30 min of physical activity was associated with a lower follow-up BMI z-score. In males, replacing 30 min of socializing (-0.03 [-0.05, -0.01]), streaming (-0.02 [-0.03, -0.01]), or gaming (-0.02 [-0.03, -0.01]) with 30 min of sleep was associated with a lower follow-up BMI z-score. In males, replacing 30 min of socializing with 30 min of gaming was associated with a lower follow-up BMI z-score (-0.01 [-0.03, -0.0001]). CoDA estimated that in males, a greater proportion of time spent in baseline socializing, relative to the remaining behaviors, was associated with a higher follow-up BMI z-score (0.05 [0.02, 0.08]). In females, no associations between screen time and BMI were observed using CoDA.

CONCLUSIONS

One-year longitudinal associations between screen time and BMI may depend on form of screen time, what behavior it replaces (physical activity or sleep), and participant sex. The alternative statistical approaches yielded somewhat different results. Experimental manipulation of screen time and investigation of biopsychosocial mechanisms underlying the observed sex differences will allow for causal inference and can inform interventions.