Natural history of insomnia symptoms in the transition from childhood to adolescence: population rates, health disparities, and risk factors

Association of Novel EEG Biomarkers of Sleep Depth and Cortical Arousability with Cardiac Autonomic Modulation in Adolescents

STUDY OBJECTIVES

To examine the developmental association of the odds ratio product (ORP), an electroencephalographic measure of sleep depth, during non-rapid eye movement (NREM) sleep with 24-hour heart rate variability (HRV), an electrocardiographic measure of cardiac autonomic modulation (CAM), in the transition to adolescence.

METHODS

Leveraging data from the Penn State Child Cohort, we performed longitudinal analyses on 313 children (median [Md] age 9 years) followed-up after Md=7.4y and cross-sectional analyses on 344 adolescents (Md=16y). We extracted ORP during NREM sleep and in the 9 seconds following cortical arousals (ORP-9) from 9-hour, in-lab polysomnography, and frequency- and time-domain HRV indices from 24-h Holter ECG monitoring. Longitudinal and cross-sectional, multivariable-adjusted, regression models examined the association between ORP and ORP-9 with adolescent 24-h HRV indices.

RESULTS

Longitudinally, a greater increase in ORP-9 since childhood was associated with lower daytime Log-LF, SDNN, RMSSD and higher HR in adolescence (p<0.05). A greater increase in ORP since childhood was associated with lower nighttime Log-LF and SDNN (p<0.05). Cross-sectionally, higher ORP and ORP-9 were associated with lower daytime and nighttime Log-LF, SDNN or RMSSD and higher HR within adolescence (p<0.05).

CONCLUSIONS

A greater increase in cortical arousability since childhood is a strong developmental predictor of daytime cardiac autonomic imbalance in adolescence. Shallower sleep depth additionally arises as a proximal determinant of both daytime and nighttime cardiac autonomic imbalance within adolescence. These data suggest a coupling between fine-grained spectral measures of the sleeping brain and those of CAM, which may inform sleep-related cardiovascular risk early in life.

The trajectories and associations of sleep disturbance symptoms with suicidal ideation in adolescents: A three-wave longitudinal study

BACKGROUND

This study aimed to investigate the developmental trajectories of sleep disturbance symptoms and examine whether specific trajectory memberships of sleep disturbance symptoms could prospectively predict suicidal ideation (SI) among a large sample of Chinese adolescents over one year.

METHODS

A three-wave longitudinal study was conducted from April 2021 to June 2022, with a sample of 19,095 adolescents from Shenzhen in Guangdong Province, China (51.2 % males; mean age = 12.4 ± 1.6 years at baseline). Socio-demographics (at baseline), SI, sleep disturbance symptoms (at each assessment), depressive symptoms (at the last follow-up), and negative life events (at two follow-ups) were assessed. Data were analyzed employing Growth Mixture Modeling and binary logistic regressions.

RESULTS

The Growth Mixture Modeling identified four trajectories of sleep disturbance symptoms over one year: resistant group (76.2 %), delayed-dysfunction group (8.8 %), recovery group (7.4 %), and chronic-dysfunction group (7.6 %). Binary logistic regression analysis revealed that adolescents in the group of delayed-dysfunction (OR = 2.86, 95 % CI = 2.51-3.27) and chronic-dysfunction (OR = 2.14, 95 % CI = 1.84-2.47) exhibited higher risks of developing SI compared to those in the resistant group, even after controlling for socio-demographics, negative life events, depressive symptoms, and baseline SI.

CONCLUSIONS

These findings underscore the importance of identifying individuals at higher risks of sleep disturbance and providing personalized and effective mental health services to reduce the incidence of SI.

Somatic Symptoms in a Population-Based Sample from Childhood to Adolescence: Stability and Concurrent and Longitudinal Predictors

The present study investigated group and individual stability and predictors of somatic symptoms from childhood to adolescence in a population-based sample. 259 youth were evaluated at 6-12 years (M 8.1) and 8 years later (M 15.2). Sixteen somatic symptoms from the parent-rated Pediatric Behavior Scale were used for analyses, in addition to psychopathology subscales. Most somatic symptom prevalence rates decreased from childhood to adolescence. Group mean scores were relatively stable over time. Individual stability for the absence of somatic symptoms in childhood and adolescence was high, yet individual stability for the presence of somatic symptoms at both time points was low. Most symptoms remitted for the majority of youth. New cases in adolescence were common. Significant correlates of childhood and adolescent somatic symptoms varied. Longitudinal predictors were childhood somatic symptoms and adolescent medication status. Childhood psychopathology scores did not predict the total adolescent somatic symptom score.

Individualized approaches to pediatric chronic insomnia: Advancing precision medicine in sleep disorders

The manifestations of chronic insomnia undergo age-related changes. In younger infants and children, behavioral insomnia emerges as the most prevalent form and typically responds to behavioral interventions. However, distinct clusters of clinical presentations suggest the presence of various phenotypes, potentially implicating the primary involvement of specific neurotransmitters. These conceptualizations, coupled with genetic studies on pleiotropy and polygenicity, may aid in identifying individuals at risk of persistent insomnia into adulthood and shed light on novel treatment options. In school-age children, the predominant presentation is sleep-onset insomnia, often linked with nighttime fears, anxiety symptoms, poor sleep hygiene, limit-setting issues, and inadequate sleep duration. The manifestations of insomnia in adolescence correlate with the profound changes occurring in sleep architecture, circadian rhythms, and homeostatic processes. The primary symptoms during adolescence include delayed sleep onset, sleep misperception, persistent negative thoughts about sleep, and physiological hyperarousal-paralleling features observed in adult insomnia. An approach centered on distinct presentations may provide a framework for precision-based treatment options. Enhanced comprehension of insomnia's manifestations across diverse developmental stages can facilitate accurate assessment. Efforts to subtype insomnia in childhood align with this objective, potentially guiding the selection of appropriate treatments tailored to individual neurobiological, clinical, and familial features.

The mediating effect of after-midnight use of digital media devices on the association of internet-related addictive behavior and insomnia in adolescents

Background

There is evidence that overexposure to digital media devices (DMD) can not only lead to addictive patterns of internet use, but also cause insomnia symptoms. The aim of this cross-sectional study among adolescents is to provide an estimate of the prevalence of sleep impairments and to explore the mediating role of after-midnight use of DMD between internet-related addictive behavior (IRAB) and insomnia.

Methods

2,712 school students from Styrian schools participated in a population-representative online survey in a supervised school setting in spring 2022. School students were screened using established and validated scales. Data analysis was carried out using multiple imputation, linear multilevel regression and mediation analysis.

Results

Prevalence estimation indicates high proportions of clinically relevant moderate [12.6% (11.3%; 14.1%)] and severe [3.6% (2.9%; 4.4%)] insomnia, with an additional 30.6% (29.0%; 32.2%) at subthreshold level. DMD are typically used after midnight an average of 1.66 (1.58; 1.75) evenings with subsequent school day per school week. Linear multilevel regression analysis shows significant associations for sleep disparities as outcome variable e.g., with generalized anxiety [b = 0.329 (0.287; 0.371)], after-midnight use of DMD [b = 0.470 (0.369; 0.572)] and IRAB [b = 0.131 (0.097; 0.165)]. Mediation analysis shows a mediated proportion of 18.2% (13.0%; 25.0%) of the association of IRAB and insomnia by after-midnight use of DMD [Indirect effect: b = 0.032 (0.023; 0.040), direct effect: b = 0.127 (0.083; 0.170)].

Conclusions

Although the cross-sectional nature of this study limits causal inference, the results indicate a need for policies, which are already in preparation in Styria as part of a respective action plan.

Diagnosis of sleep disorders in child healthcare settings

OBJECTIVES

Sleep disorders impact at least 10 % of children, pose risks to overall wellbeing, and are key targets of preventive interventions. The objectives of this study were to describe the prevalence of pediatric sleep disorder diagnoses across sociodemographic characteristics and co-occurring conditions, and to explore potential sociodemographic disparities.

METHODS

Cross-sectional analysis of 12,394,902 children (0-17 years; 50.9 % Medicaid-insured) in the 2017 MarketScan database. Prevalence was assessed utilizing ICD-10 codes, with multivariate logistic regressions examining disparities (insurance coverage; race and ethnicity in Medicaid-insured) for diagnoses in ≥0.10 % of children.

RESULTS

The prevalence of sleep disorder diagnoses was 2.36 %. The most common diagnoses were obstructive sleep disordered breathing (oSDB, 1.17 %), unspecified sleep disorders (0.64 %), insomnia (0.52 %), and other SDB (0.10 %), with <0.10 % for all other diagnoses. Insomnia and parasomnias diagnoses were much lower than diagnostic estimates. Sleep diagnoses were more prevalent in Medicaid versus commercially insured youth, 2-5-year-olds, and in children with co-occurring medical, neurodevelopmental, or behavioral health conditions. Girls and boys were generally equally likely to be diagnosed with any sleep disorder. In Medicaid-insured children, white children were more likely to have any sleep diagnosis compared to all other racial and ethnic groups. Black/African American children were more likely than white children to have oSDB.

CONCLUSIONS

Compared to diagnostic estimates, claims data suggest sleep disorders are under-diagnosed, with notable sociodemographic disparities. Findings suggest a need for clinical resources to identify and address sleep disorders and to understand biases potentially driving disparities, given that sleep is a modifiable determinant of child wellbeing.

European expert guidance on management of sleep onset insomnia and melatonin use in typically developing children

Sleeping problems are prevalent among children and adolescents, often leading to frequent consultations with pediatricians. While cognitive-behavioral therapy has shown effectiveness, especially in the short term, there is a lack of globally endorsed guidelines for the use of pharmaceuticals or over-the-counter remedies in managing sleep onset insomnia. An expert panel of pediatric sleep specialists and chronobiologists met in October 2023 to develop practical recommendations for pediatricians on the management of sleep onset insomnia in typically developing children. When sleep onset insomnia is present in otherwise healthy children, the management should follow a stepwise approach. Practical sleep hygiene indications and adaptive bedtime routine, followed by behavioral therapies, must be the first step. When these measures are not effective, low-dose melatonin, administered 30-60 min before bedtime, might be helpful in children over 2 years old. Melatonin use should be monitored by pediatricians to evaluate the efficacy as well as the presence of adverse effects.    Conclusion: Low-dose melatonin is a useful strategy for managing sleep onset insomnia in healthy children who have not improved or have responded insufficiently to sleep hygiene and behavioral interventions.

Racial/ethnic disparities in the trajectories of insomnia symptoms from childhood to young adulthood

STUDY OBJECTIVES

To examine differences in the longitudinal prevalence of childhood insomnia symptoms across black/African American, Hispanic/Latinx, and non-Hispanic white groups.

METHODS

Participants were 519 children from the Penn State Child Cohort (baseline [V1] from 2000-2005) who were followed up 8 years later as adolescents (V2) and 15 years later as young adults (S3). Mean age at S3 was 24.1 ± 2.7 years. Approximately, 76.5% identified as non-Hispanic white, 12.9% as black/African American, 7.1% as Hispanic/Latinx, and 3.5% as "other" race/ethnicity. Insomnia symptoms were defined as parent-reported (childhood) or self-reported (adolescence and young adulthood) moderate-to-severe difficulties initiating/maintaining sleep. Longitudinal trajectories of insomnia symptoms were identified across three-time points and the odds of each trajectory were compared between racial/ethnic groups, adjusting for sex, age, overweight, sleep apnea, periodic limb movements, psychiatric/behavioral disorders, and psychotropic medication use.

RESULTS

Black/African Americans compared to non-Hispanic whites were at significantly higher odds of having a childhood-onset persistent trajectory through young adulthood (OR = 2.58, 95% CI [1.29, 5.14]), while Hispanics/Latinx were at nonsignificantly higher odds to have the same trajectory (OR = 1.81, 95% CI [0.77, 4.25]). No significant racial/ethnic differences were observed for remitted and waxing-and-waning trajectories since childhood or incident/new-onset trajectories in young adulthood.

CONCLUSIONS

The results indicate that disparities in insomnia symptoms among black/African American and, to a lesser extent, Hispanic/Latinx groups start early in childhood and persist into young adulthood. Identifying and intervening upon upstream determinants of racial/ethnic insomnia disparities are warranted to directly address these disparities and to prevent their adverse health sequelae.

CLINICAL TRIAL INFORMATION

N/A; Not a clinical trial.

Edward O. Bixler, PhD: from the Apollo project and chimpanzees to sleep epidemiology

What an honor to write about Dr. Edward O. Bixler's contributions to the sleep field. In 1967, Dr. Bixler published a case report on a chimpanzee with implanted brain electrodes while working at an Air Force base in New Mexico. A few years later, in 1971, he published on the sleep effects of flurazepam in individuals with insomnia together with Dr. Anthony Kales, data that he had collected when the Sleep Research & Treatment Center (SRTC) was housed at the University of California Los Angeles. Dr. Bixler, a meticulous scientist, learned from Dr. Kales, a devoted clinician, to study "the whole patient, and all aspects of sleep," a legacy that continued when the SRTC moved to Penn State in Hershey. Indeed, Dr. Bixler's tenure at Penn State from 1971 until 2019 kept the science of the SRTC focused on that premise and helped translate scientific evidence into clinical care. He not only contributed early to the pharmacology of sleep and the effects of hypnotics, but he was also a pioneer in "sleep epidemiology." His "Prevalence of sleep disorders in the Los Angeles metropolitan area" study of 1979 was the first rigorous epidemiological study on sleep disturbances. Starting in 1990, he established the Penn State Adult Cohort to estimate the prevalence and natural history of sleep-disordered breathing and other sleep disorders in adults. Inspired by life-course epidemiology, he established in 2001 the Penn State Child Cohort to estimate the same phenomena in children. This Living Legend paper captures and highlights Dr. Bixler's enduring legacy to sleep science.

The relationship between multiple sleep dimensions and obesity in adolescents: A systematic review

Sleep is an involuntary behaviour, biologically fundamental to survival and wellbeing. However, sleep is increasingly neglected, with significant health implications. Recent research has identified associations between sleep duration, quality, timing and risk of overweight/obesity in children and adults. The aim of this review was to systematically identify and examine research that investigates the relationships between multiple objective and subjective sleep outcomes and objective adiposity measures in adolescents. A systematic review of literature, published to December 2022, was conducted using ten bibliographic databases. Search terms included objective and subjective sleep/circadian rhythm outcomes, objective adiposity measurements, and adolescents aged 8-18 years. Eighty-nine studies were included in the final review. Sleep outcomes were synthesized into three sleep domains: pre-sleep, during sleep and post-sleep outcomes. In summary, pre-sleep outcomes (including poor sleep hygiene, later chronotype and increased variability and later sleep timings) and increased sleep disturbance are consistently significantly associated with increased obesity and adiposity in adolescents. The relationship between during-sleep outcomes (sleep quality and efficiency) with adiposity and obesity measures was mixed. These findings suggest that adapting an individual's schedule to best suit chronotype preference and improving sleep hygiene, including a consistent bedtime routine, could reduce adiposity and obesity in adolescents.

The association between sleep quality and obstructive sleep apnea with health-related quality of life in children with obesity

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) and poor sleep quality are highly prevalent in children with obesity, but their individual associations with health-related quality of life (HRQOL) are unknown in this population. The primary objective was to describe the independent association of OSA and sleep quality with HRQOL in children with obesity.

METHODS

This was a cross-sectional study of children with obesity at 2 tertiary care centers. Sleep quality and HRQOL were measured with the Pittsburgh Sleep Quality Index and Pediatric Quality of Life Inventory questionnaires, respectively. Multivariable regression models were created to evaluate associations between OSA and sleep quality with HRQOL.

RESULTS

There were 98 children (median age 15.0 years, median body mass index z-score 3.8, 44% females). Among the study population, 49/98 (50%) children reported poor sleep quality, 41/98 (42%) children had OSA, and 52/98 (53%) children reported impaired HRQOL. Self-reported poor sleep quality was independently associated with reduced HRQOL, whereas the presence of OSA was not. Children with poor sleep quality had a reduced Pediatric Quality of Life Inventory score by 8.8 compared to children with good sleep quality (95% confidence interval, 2.6-14.9; P = .006), when adjusting for age, sex, body mass index z-score, attention-deficit/hyperactivity disorder, mood/anxiety disorder, and study site.

CONCLUSIONS

In the current study of children with obesity, we found that HRQOL was more strongly associated with the self-reported experience of sleep than the presence of OSA. Clinicians should assess and optimize sleep quality as part of the evaluation for OSA in children with obesity.

CITATION

Xiao L, Voutsas G, Ryan CM, Katz SL, Narang I. The association between sleep quality and obstructive sleep apnea with health-related quality of life in children with obesity. J Clin Sleep Med. 2023;19(11):1877-1883.

Disparities in Sleep-Disordered Breathing: Upstream Risk Factors, Mechanisms, and Implications

Sleep-disordered breathing (SDB) refers to a spectrum of disorders ranging from habitual snoring without frank episodes of obstructed breathing or desaturation during sleep to obstructive sleep apnea, where apneas and hypopneas repetitively occur with resultant intermittent hypoxia, arousal, and sleep disruption. Disparities in SDB reflect its overall high prevalence in children and adults from racially and ethnically minoritized or low socioeconomic status backgrounds coupled with high rates of underdiagnosis and suboptimal treatment.

Sleep Disorders in Childhood

OBJECTIVE

This article provides a comprehensive review of pediatric sleep disorders including the clinical features, diagnosis, and treatment of sleep-disordered breathing, insomnia, parasomnias, restless sleep disorder, restless legs syndrome, narcolepsy in childhood, and Kleine-Levin syndrome.

LATEST DEVELOPMENTS

Our understanding of pediatric sleep pathophysiology continues to evolve, and diagnostic and treatment modalities have expanded. A low-sodium oxybate formulation was approved in July 2020 in the United States to treat cataplexy and excessive daytime sleepiness in patients 7 years old and older with narcolepsy. A validated pediatric hypersomnolence survey for pediatric narcolepsy and idiopathic hypersomnia with high sensitivity, specificity, and interrater reliability is now available.

ESSENTIAL POINTS

The clinical presentation, diagnostics, and treatment of children with sleep disorders differ from those of adults. Untreated sleep disorders in childhood can lead to adverse physical and psychological consequences in adults. Correctly diagnosing and treating sleep disorders in youth can prevent a significant burden of disease in adulthood.

Pediatric sleep: current knowledge, gaps, and opportunities for the future

This White Paper addresses the current gaps in knowledge, as well as opportunities for future studies in pediatric sleep. The Sleep Research Society's Pipeline Development Committee assembled a panel of experts tasked to provide information to those interested in learning more about the field of pediatric sleep, including trainees. We cover the scope of pediatric sleep, including epidemiological studies and the development of sleep and circadian rhythms in early childhood and adolescence. Additionally, we discuss current knowledge of insufficient sleep and circadian disruption, addressing the neuropsychological impact (affective functioning) and cardiometabolic consequences. A significant portion of this White Paper explores pediatric sleep disorders (including circadian rhythm disorders, insomnia, restless leg and periodic limb movement disorder, narcolepsy, and sleep apnea), as well as sleep and neurodevelopment disorders (e.g. autism and attention deficit hyperactivity disorder). Finally, we end with a discussion on sleep and public health policy. Although we have made strides in our knowledge of pediatric sleep, it is imperative that we address the gaps to the best of our knowledge and the pitfalls of our methodologies. For example, more work needs to be done to assess pediatric sleep using objective methodologies (i.e. actigraphy and polysomnography), to explore sleep disparities, to improve accessibility to evidence-based treatments, and to identify potential risks and protective markers of disorders in children. Expanding trainee exposure to pediatric sleep and elucidating future directions for study will significantly improve the future of the field.

Short-term and intermediate-term fine particulate air pollution are synergistically associated with habitual sleep variability in adolescents - A cross-sectional study

BACKGROUND

Both air pollution and poor sleep have been associated with increased risk of cardiovascular diseases. However, the association between air pollution and sleep health, especially among adolescents, is rarely investigated.

METHODS

To investigate the association between fine particulate (PM2.5) air pollution and habitual sleep patterns, we analyzed data obtained from 246 adolescents who participated in the Penn State Child Cohort follow-up examination. We collected their individual-level 24-h (short-term) PM2.5 concentration by using a portable monitor. We estimated their residential-level PM2.5 concentration during the 60-day period prior to the examination (intermediate-term) using a kriging approach. Actigraphy was used to measure participants' sleep durations for seven consecutive nights. Habitual sleep duration (HSD) and sleep variability (HSV) were calculated as the mean and SD of the seven-night sleep duration. Multivariable-adjusted linear regression models were used to assess the association between PM2.5 exposures and HSD/HSV. An interaction between short-term and intermediate-term PM2.5 was created to explore their synergistic associations with HSD/HSV.

RESULTS

Elevated short-term and intermediate-term PM2.5 exposure were significantly (p < 0.05) associated with higher HSV, but not HSD. Specifically, the mean (95% CI) increase in HSV associated with 1 SD higher 24-h (26.3 μg/m3) and 60-day average (2.2 μg/m3) PM2.5 were 14.6 (9.4, 14.8) and 4.9 (0.5, 9.2) minutes, respectively. In addition, there was a synergistic interaction (p = 0.08) between short-term and intermediate-term PM2.5 exposure on HSV, indicative that the association between intermediate-term PM2.5 and HSV became stronger as short-term PM2.5 increases, and vice versa.

CONCLUSION

Short-term individual-level and intermediate-term residential-level PM2.5 exposures are adversely and synergistically associated with increased sleep variability, an indicator of instability of sleep quantity, in adolescents. Through such an association with sleep pattern, PM2.5 air pollution may increase long-term cardiometabolic risks.

Health Disparities in Pediatric Sleep

This article reviews disparities in pediatric sleep health and sleep disorders from early childhood through adolescence (birth to age 18 years). Sleep health is a multidimensional construct including sleep duration, consolidation, and other domains, whereas sleep disorders reflect both behaviorally (eg, insomnia) and medically based (eg, sleep disordered breathing) sleep diagnoses. Using a socioecological framework, we review multilevel (ie, child, family, school, health-care system, neighborhood, and sociocultural) factors linked to sleep health disparities. Mechanistic research and studies using an intersectional lens to understand overlapping marginalized identities are needed to inform multilevel interventions to promote sleep health equity in pediatrics.

Associations of Changes in Sleep and Emotional and Behavioral Problems From Late Childhood to Early Adolescence

Importance

Sleep problems and psychopathology symptoms are highly comorbid and bidirectionally correlated across childhood and adolescence. Whether these associations are specific to discrete profiles of sleep problems and specific internalizing and externalizing phenomena is currently unclear.

Objective

To characterize individual changes in profiles of sleep problems and their prospective associations with psychopathology symptoms across the transition from childhood to adolescence.

Design, Setting, and Participants

This observational cohort study used baseline data (participant age of 9 to 11 years) and 2-year follow-up data (participant age of 11 to 13 years) from the community-setting, multicenter Adolescent Brain Cognitive Development (ABCD) study. Individuals were assessed for a range of sleep problems at both waves and categorized into profiles via latent profile analysis. The stability and change in these profiles over time was assessed via latent transition analysis. Logistic regression models examined whether psychopathology symptoms were cross-sectionally associated with profile membership and whether transitions between profiles were associated with changes psychopathology symptoms over time. Data were collected from September 2016 to January 2020, and data were analyzed from August 2021 to July 2022.

Exposures

Sleep problems were assessed at both baseline and follow-up via the parent-reported Sleep Disturbance Scale for Children (SDSC).

Main Outcomes and Measures

Psychopathology symptoms at both baseline and follow-up were assessed using the internalizing and externalizing dimension scores derived from the parent-reported Child Behavior Checklist.

Results

A total of 10 313 individuals (4913 [47.6%] were female) were categorized into 4 latent profiles of sleep problems at both baseline and follow-up: a low disturbance profile, a sleep onset/maintenance problems profile, a moderate and nonspecific disturbance profile (termed mixed disturbance), and a high disturbance profile. Individuals in the 3 more severe problem profiles displayed greater risk of concurrent internalizing symptoms (sleep onset/maintenance problems: odds ratio [OR], 1.30; 95% CI, 1.25-1.35; P < .001; mixed disturbance: OR, 1.29; 95% CI, 1.25-1.33; P < .001; high disturbance: OR, 1.44; 95% CI, 1.40-1.49; P < .001) and externalizing symptoms (sleep onset/maintenance problems: OR, 1.20; 95% CI, 1.16-1.23; P < .001; mixed disturbance: OR, 1.17; 95% CI, 1.14-1.20; P < .001; high disturbance: OR, 1.24; 95% CI, 1.21-1.28; P < .001). Transitions between sleep profiles over time were associated with prospective internalizing and externalizing symptoms, but not vice versa.

Conclusions and Relevance

There are substantial changes in sleep problems across the transition to adolescence that are associated with later internalizing and externalizing symptoms. Sleep profiles could be targeted in future intervention and treatment programs to improve sleep-related and mental health-related outcomes across development.

Sleep Deprivation and Insomnia in Adolescence: Implications for Mental Health

Sleep changes significantly throughout the human lifespan. Physiological modifications in sleep regulation, in common with many mammals (especially in the circadian rhythms), predispose adolescents to sleep loss until early adulthood. Adolescents are one-sixth of all human beings and are at high risk for mental diseases (particularly mood disorders) and self-injury. This has been attributed to the incredible number of changes occurring in a limited time window that encompasses rapid biological and psychosocial modifications, which predispose teens to at-risk behaviors. Adolescents' sleep patterns have been investigated as a biunivocal cause for potential damaging conditions, in which insufficient sleep may be both a cause and a consequence of mental health problems. The recent COVID-19 pandemic in particular has made a detrimental contribution to many adolescents' mental health and sleep quality. In this review, we aim to summarize the knowledge in the field and to explore implications for adolescents' (and future adults') mental and physical health, as well as to outline potential strategies of prevention.

The trajectories and associations of insomnia symptoms with addictive behaviours in adolescents: A two-year longitudinal study

Insomnia displays heterogeneous trajectories across adolescence, which may induce addictive behaviours, including internet gaming disorder and substance use. This study aimed to investigate the latent trajectory classes of insomnia symptoms over 2 years and to examine the associations between insomnia trajectories and these addictive behaviours. Participants were 910 adolescents from six middle schools in Shanghai, China (52.7% males; mean age = 13.17 years). The three-wave survey measured insomnia symptoms, internet gaming disorder, substance use, depressive symptoms, and sociodemographic characteristics from 7th to 9th grade. Latent class growth modelling was performed to identify the latent trajectory classes of insomnia symptoms. Then multivariable logistic regressions were conducted within the best-fitting latent class growth model to examine the associations of insomnia trajectories with internet gaming disorder and substance use. Two latent trajectory classes of insomnia symptoms were recognised: the non-insomnia group (71.8%) and the insomnia group (28.2%). In the multivariable analysis controlling for baseline demographic variables and depressive symptoms, the insomnia group had a higher risk of developing internet gaming disorder (OR = 2.203 [95% CI: 1.258-3.858]) and substance use (OR = 2.215 [95% CI: 1.324-3.705]) compared with the non-insomnia group. These findings add to a growing body of research on heterogeneous trajectories of insomnia symptoms during adolescence, suggesting that intervention strategies are needed to target the characteristics or developmental patterns of different insomnia subgroups. The ultimate goal is to mitigate the impact of insomnia symptoms on adolescent addictive behaviours.

Chronic insomnia of early childhood: Phenotypes and pathophysiology

This paper aims to review the limitations of the current classification of insomnia of early childhood and propose a new conceptual model allowing a better understanding of its pathophysiology. Our hypothesis is that chronic insomnia of childhood has different phenotypical expressions, associated to different pathophysiological mechanisms. Based on a long-lasting experience in evaluating a very large number of children with specific insomnia symptoms (nocturnal awakenings, difficulty in falling asleep, nocturnal restlessness, early morning awakenings) and on published data, we hypothesize that different phenotypes of insomnia might exist with different therapeutic implications. We describe three phenotypes of insomnia in early childhood: a) insomnia with motor restlessness; b) insomnia characterized without difficulties in falling asleep but with long-lasting early morning awakenings; c) insomnia with multiple night awakenings and falling asleep difficulty. This type of categorization might have important implications for treatment, based on the different hypothetical neurotransmitter dysfunctions. The early identification of a phenotype of insomnia might guide to specific behavioral and/or pharmacological interventions with the aim to prevent chronic insomnia.

Association of a novel EEG metric of sleep depth/intensity with attention-deficit/hyperactivity, learning, and internalizing disorders and their pharmacotherapy in adolescence

STUDY OBJECTIVES

Psychiatric/learning disorders are associated with sleep disturbances, including those arising from abnormal cortical activity. The odds ratio product (ORP) is a standardized electroencephalogram metric of sleep depth/intensity validated in adults, while ORP data in youth are lacking. We tested ORP as a measure of sleep depth/intensity in adolescents with and without psychiatric/learning disorders.

METHODS

Four hundred eighteen adolescents (median 16 years) underwent a 9-hour, in-lab polysomnography. Of them, 263 were typically developing (TD), 89 were unmedicated, and 66 were medicated for disorders including attention-deficit/hyperactivity (ADHD), learning (LD), and internalizing (ID). Central ORP during non-rapid eye movement (NREM) sleep was the primary outcome. Secondary/exploratory outcomes included central and frontal ORP during NREM stages, in the 9-seconds following arousals (ORP-9), in the first and second halves of the night, during REM sleep and wakefulness.

RESULTS

Unmedicated youth with ADHD/LD had greater central ORP than TD during stage 3 and in central and frontal regions during stage 2 and the second half of the sleep period, while ORP in youth with ADHD/LD on stimulants did not significantly differ from TD. Unmedicated youth with ID did not significantly differ from TD in ORP, while youth with ID on antidepressants had greater central and frontal ORP than TD during NREM and REM sleep, and higher ORP-9.

CONCLUSIONS

The greater ORP in unmedicated youth with ADHD/LD, and normalized levels in those on stimulants, suggests ORP is a useful metric of decreased NREM sleep depth/intensity in ADHD/LD. Antidepressants are associated with greater ORP/ORP-9, suggesting these medications induce cortical arousability.

Trajectories of Insomnia Symptoms From Childhood Through Young Adulthood

OBJECTIVES

Insomnia symptoms are transdiagnostic to physical and mental health disorders. Given the lack of population-based cohorts with objective sleep measures and long-term follow-ups, little is known about the chronicity of childhood insomnia symptoms. We determined the developmental trajectories of insomnia symptoms, their evolution into adult insomnia, and the role of objective sleep duration in the transition to adulthood.

METHODS

A total of 502 children (median 9 years old, 71.7% response rate) were studied 7.4 years later as adolescents (median 16 years old) and 15 years later as adults (median 24 years old). Insomnia symptoms were ascertained as moderate-to-severe difficulties initiating and/or maintaining sleep via parent- or self reports at all 3 time points, adult insomnia via self-report in young adulthood, and objective short-sleep duration via polysomnography in childhood and adolescence.

RESULTS

Among children with insomnia symptoms, the most frequent trajectory was persistence (43.3%), followed by remission (26.9% since childhood, 11.2% since adolescence) and a waxing-and-waning pattern (18.6%). Among children with normal sleep, the most frequent trajectory was persistence (48.1%), followed by developing insomnia symptoms (15.2% since adolescence, 20.7% in adulthood) and a waxing-and-waning pattern (16.0%). The odds of insomnia symptoms worsening into adult insomnia (22.0% of children, 20.8% of adolescents) were 2.6-fold and 5.5-fold among short-sleeping children and adolescents, respectively.

CONCLUSIONS

Early sleep interventions are a health priority because pediatricians should not expect insomnia symptoms to developmentally remit in a high proportion of children. Objective sleep measures may be clinically useful in adolescence, a critical period for the adverse prognosis of the insomnia with short-sleep duration phenotype.

Evidence of a maturational disruption in non-rapid eye movement sleep slow wave activity in youth with attention-deficit/hyperactivity, learning and internalizing disorders

BACKGROUND

Sleep slow wave activity (SWA) peaks during childhood and declines in the transition to adolescence during typical development (TD). It remains unknown whether this trajectory differs in youth with neuropsychiatric disorders.

METHODS

We analyzed sleep EEGs of 664 subjects 6 to 21 y (449 TD, 123 unmedicated, 92 medicated) and 114 subjects 7-12 y (median 10.5 y) followed-up at 18-22 y (median 19 y). SWA (0.4-4 Hz) power was calculated during non-rapid eye movement sleep.

RESULTS

TD and unmedicated youth showed cubic central and frontal SWA trajectories from 6 to 21 y (p-cubic<0.05), with TD youth showing peaks in central SWA at 6.8 y and frontal at 8.2 y. Unmedicated attention-deficit/hyperactivity (ADHD) and/or learning disorders (LD) showed peak central SWA 2 y later (at 9.6 y, coinciding with peak frontal SWA) than TD, followed by a 67% steeper slope by 19 y. Frontal SWA peak and slope in unmedicated ADHD/LD, and that of central and frontal in internalizing disorders (ID), were similar to TD. Unmedicated ADHD/LD did not differ in the longitudinal SWA percent change by 18-22 y; unmedicated ID showed a lower longitudinal change in frontal SWA than TD. Medicated youth showed a linear decline in central and frontal SWA from 6 to 21 y (p-linear<0.05).

CONCLUSIONS

ADHD/LD youth show a maturational delay and potential topographical disruption in SWA during childhood and steeper decline throughout adolescence, suggesting faster synaptic pruning. Youth with ID experience less changes in frontal SWA by late adolescence. Psychotropic medications may impact the maturational trajectory of SWA, but not the magnitude of developmental decline by late adolescence.