Long-Term Melatonin Therapy for Adolescents and Young Adults with Chronic Sleep Onset Insomnia and Late Melatonin Onset: Evaluation of Sleep Quality, Chronotype, and Lifestyle Factors Compared to Age-Related Randomly Selected Population Cohorts

Melatonin use in managing insomnia in typically developing (TD) children: A technical report

Although melatonin is widely used globally for the management of insomnia in children and adolescents, there are few clinical guidelines available for healthcare practitioners, particularly in typically developing (TD) children. Because existing data are either sparse or inconclusive, a task force comprised of pediatric sleep researchers and clinicians was established by the International Pediatric Sleep Association (IPSA) to first examine the available literature and to develop a set of evidence-based (when possible) and consensus-based recommendations to guide practitioners in decision-making regarding melatonin use in pediatric insomnia. A summary of the evidence pertaining to melatonin's use in pediatric clinical settings, and efficacy and safety in TD children is presented below as a companion to an accompanying list of specific recommendations.

Patient-level analysis of the cost and variation in melatonin prescribing patterns in those under 18 in the North East of England

BACKGROUND

Melatonin is widely used to promote sleep in both normally developing children and adolescents and those with neurodevelopmental disorders. It has an evidence base as both hypnotic and chronobiotic although the optimum dose and timing remain unclear. There are now a wide variety of different preparations of melatonin both immediate and prolonged release. We reviewed annual national and regional prescribing data and undertook a detailed review of one year of melatonin prescriptions issued to those under 18 within one of the UK's dedicated paediatric hospitals, this included a cost analysis. This was to understand whether prescribing was appropriate, whether behavioural therapies had been recommended first and whether there had been consideration of other causes of poor sleep, such as sleep apnoea.

METHODS

Between November 2020 and October 2021, 220 patients under 18 had one or more melatonin prescriptions issued to treat poor sleep. The audit assessed whether prescriptions were issued in accordance with local Melatonin Shared Care Guidance standards that emphasise: an initial behavioural approach, fixed timing, use of licensed preparations and review of benefit. This included a detailed review of electronic patient care records. A cost analysis of the different preparations was also made.Results adherence to the audit were not met for any of the audit standards, only 9% had a prior behavioural intervention, and only 15% had another sleep disorder considered. Community prescribers were more likely to give advice on timing and review any subsequent benefit. The total costs of prescriptions were £13 299 of which £8736 was issued as off licence, liquid suspension.

CONCLUSION

The audit highlighted a lack of knowledge about appropriate melatonin prescribing and led to a trust-wide sleep education programme. It additionally highlighted the cost and potential risk of inappropriate prescribing and a clear need for better access to effective behavioural interventions.

Mensorio M, Cisneros Hernández AA, Lourenço dos Santos R, Nieto Ramos EG, Albán-Terán MG, Mateu-Mollá J, Ramírez-Martínez FR, Colmenero Guadián AM, Martínez-Rubio D, Langer ÁI, Araya C, Castellanos-Vargas RO. Internet-based self-administered intervention to reduce anxiety and depression symptomatology and improve well-being in 7 countries: protocol of a randomized control trial

Background

Online psychological interventions have emerged as a treatment alternative because they are accessible, flexible, personalized, and available to large populations. The number of Internet interventions in Latin America is limited, as are Randomized Controlled Trials (RCTs) of their effectiveness and a few studies comparing their effectiveness in multiple countries at the same time. We have developed an online intervention, Well-being Online, which will be available to the public free of charge in 7 countries: Mexico, Ecuador, Peru, Chile, Brazil, Spain, and the Netherlands. We expect a reduction in depression and anxiety symptoms and an increase in well-being of the participants.

Methods

A multi-country, randomized controlled trial will be conducted. The intervention is multicomponent (Cognitive Behavioral Therapy, Behavioral Activation Therapy, Mindfulness, Acceptance and Commitment Therapy, and Positive Psychology), with 10 sessions. In each country, eligible participants will be randomized to one of three groups: Enriched Intervention (interactive web design with videos, infographics, text, audio, and forum), Text Intervention (text on the website), and Wait List (control group). Repeated measures will be obtained at 5-time points. Our primary outcomes will be anxiety symptomatology, depressive symptomatology, and mental well-being. MANOVA analysis will be used for our main analysis.

Discussion

This protocol describes the design of a randomized trial to evaluate the efficacy of a web-based intervention to reduce anxiety and depression symptomatology and increase subjective well-being. The intervention will be made available in four languages (Spanish, Portuguese, Dutch, and English). Its results will contribute to the evidence of effectiveness in terms of randomized trials and Internet interventions, mainly in Latin America and Europe.

Quality of melatonin use in children and adolescents: findings from a UK clinical audit

BACKGROUND

Melatonin is commonly used to treat sleep disturbance in children and adolescents, although uncertainties about its optimal use remain.

OBJECTIVE

To determine to what extent prescribing of melatonin complies with evidence-based clinical practice standards.

METHODS

As part of a quality improvement programme, the Prescribing Observatory for Mental Health conducted a retrospective clinical audit in UK services for children and adolescents.

FINDINGS

Data were submitted for 4151 children and adolescents up to 18 years of age, treated with melatonin: 3053 (74%) had a diagnosis of neurodevelopmental disorder. In 2655 (73%) of the 3651 patients prescribed melatonin to be taken regularly, the main reason was to reduce sleep latency (time taken to fall asleep). In 409 patients recently starting melatonin, a non-pharmacological intervention had already been tried in 279 (68%). The therapeutic response of patients early in treatment (n=899) and on long-term treatment (n=2353) had been assessed and quantified in 36% and 31%, respectively, while for review of side effects, the respective proportions were 46% and 43%. Planned treatment breaks were documented in 317 (13%) of those on long-term treatment.

CONCLUSIONS

Melatonin was predominantly prescribed for evidence-based clinical indications, but the clinical review and monitoring of this treatment fell short of best practice.

CLINICAL IMPLICATIONS

With limited methodical review of melatonin use in their patients, clinicians will fail to garner reliable information on its risks and benefits for individual patients. The lack of such practice-based evidence may increase the risk of melatonin being inappropriately targeted or continued despite being ineffective or no longer indicated.

Sleep problems in children and adolescents in an attention deficit hyperactivity disorder service

OBJECTIVES

Sleep problems are common amongst children and adolescents with attention deficit hyperactivity disorder (ADHD). The purpose of this study was to investigate sleep problems in children and adolescents attending a specialist ADHD service.

METHODS

This was a cross-sectional online survey combined with a retrospective chart review, conducted in the ADHD Assessment, Diagnosis, Management, initiation, Research and Education (ADMiRE) service, the first public specialist ADHD service for young people in Ireland. Participants were caregivers of children and adolescents with ADHD attending ADMiRE. Sleep was assessed using The Children's Sleep Habits Questionnaire (CSHQ) and ADHD symptoms were assessed using an abbreviated version of the Swanson, Nolan and Pelham Teacher and Parent Rating Scale (SNAP-IV). Details regarding patient demographics, co-morbidities and medication were collected from patient records.

RESULTS

Eighty-four percent of young people scored above the clinical cut-off for a sleep disorder. The most frequently reported sleep problems were related to sleep onset and sleep duration, and 64% of respondents met the criteria for two or more sleep problems. ADHD severity was associated with greater sleep problems. Co-morbid physical, neurodevelopmental, and mental health disorders as well as stimulant use were not associated with greater sleep problems.

CONCLUSION

Sleep problems are very common amongst children and adolescents with ADHD. This study has demonstrated an association between more sleep problems and ADHD severity. These findings highlight the need for both effective ADHD treatment to ensure optional sleep in young people as well as effective interventions for sleep problems to prevent worsening of ADHD symptoms.

The short-term and long-term adverse effects of melatonin treatment in children and adolescents: a systematic review and GRADE assessment

Background

Currently, melatonin is used to treat children and adolescents with insomnia without knowing the full extent of the short-term and long-term consequences. Our aim was to provide clinicians and guideline panels with a systematic assessment of serious-and non-serious adverse events seen in continuation of melatonin treatment and the impact on pubertal development and bone health following long-term administration in children and adolescents with chronic insomnia.

Methods

We searched PubMed, Embase, Cinahl and PsycINFO via Ovid, up to March 17, 2023, for studies on melatonin treatment among children and adolescents (aged 5-20 years) with chronic insomnia. The language was restricted to English, Danish, Norwegian, and Swedish. Outcomes were non-serious adverse events and serious adverse events assessed 2-4 weeks after initiating treatment and pubertal development and bone health, with no restriction on definition or time of measurement. Observational studies were included for the assessment of long-term outcomes, and serious and non-serious adverse events were assessed via randomised studies. The certainty of the evidence was assessed using Grades of Recommendation, Assessment, Development and Evaluation (GRADE). The protocol is registered with the Danish Health Authority.

Findings

We identified 22 randomised studies with 1350 patients reporting on serious-and non-serious adverse events and four observational studies with a total of 105 patients reporting on pubertal development. Melatonin was not associated with serious adverse events, yet the number of patients experiencing non-serious adverse events was increased (Relative risk 1.56, 95% CI 1.01-2.43, 17 studies, I² = 47%). Three studies reported little or no influence on pubertal development following 2-4 years of treatment, whereas one study registered a potential delay following longer treatment durations (>7 years). These findings need further evaluation due to several methodological limitations.

Interpretation

Children who use melatonin are likely to experience non-serious adverse events, yet the actual extent to which melatonin leads to non-serious adverse events and the long-term consequences remain uncertain. This major gap of knowledge on safety calls for caution against complacent use of melatonin in children and adolescents with chronic insomnia and for more research to inform clinicians and guideline panels on this key issue.

Funding

The Danish Health Authority. The Parker Institute, Bispebjerg and Frederiksberg Hospital, supported by the Oak Foundation.

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

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

Factors associated with melatonin use in child sleep disturbance: A survey of Australian parents

OBJECTIVE

Sleep disturbances are prevalent in Australian children and cause a significant amount of stress to both children and their parents. If sleep disturbances are left untreated, they can result in detrimental consequences to both child and parental wellbeing. While behavioural interventions are recognised as the gold standard treatment for paediatric insomnia, there is a growing use of melatonin from both prescription and non-prescription sources in paediatrics. However, empirical research on the efficacy and safety of melatonin for children is sparse, conflicting, and inconsistent. This first Australian study aimed to investigate correlates of melatonin use in a sample of children with sleep disturbance in Australia and assess whether melatonin is being administered to children contrary to Therapeutic Goods Administration Guidelines.

METHODS

An exploratory online study was undertaken with 318 parents of Australian children with sleep disturbance (95.30% females). Logistic regression, mediation and descriptive analysis were conducted.

RESULTS

As hypothesised, higher parental stress, older child age, and a diagnosis of ADHD were significantly associated with melatonin use in this sleep disturbed sample. Other potential correlates such as financial stress, number of household dependents, child sleep disturbance, and autism were not significantly associated with melatonin use in adjusted analyses.

CONCLUSION

Findings show off-label melatonin use in children with sleep disturbance is prevalent. For the first time, this study showed an indirect path linking child sleep disturbances with melatonin use via parental stress. Overall, while the safety of melatonin use remains unknown, there is a clear need to mitigate parental stress to minimise potentially unmonitored and improper use of melatonin in children.

Chronic Administration of Melatonin: Physiological and Clinical Considerations

Background: Exogenous melatonin is commonly used to treat insomnia, other sleep problems, and numerous medical illnesses, including Alzheimer’s disease, autism spectrum disorder, and mild cognitive impairment in adults and children. There is evolving information regarding issues with the use of chronic melatonin. Methods: The present investigation was a narrative review. Results: Melatonin usage has risen dramatically in recent years. Many countries only allow melatonin prescriptions. In the United States (U.S.), it is classified as a dietary supplement accessible over the counter and can be derived from animals, microorganisms, or, most commonly, made synthetically. No regulatory agency oversees its manufacturing or sale in the U.S. melatonin concentration of marketed preparations varies widely between product labels and manufacturers. Melatonin’s ability to induce sleep is detectable. However, it is modest for most people. Sleep length appears to be less important in sustained-release preparations. The optimal dosage is unknown, and routinely used amounts vary substantially. Melatonin’s short-term negative effects are minimal, resolve at medicine cessation, and do not usually prevent usage overall. Much research on long-term melatonin administration has found no difference between exogenous melatonin and placebo in terms of long-term negative effects. Conclusion: Melatonin at low to moderate dosages (approximately 5–6 mg daily or less) appears safe. Long-term usage appears to benefit certain patient populations, such as those with autism spectrum disorder. Studies investigating potential benefits in reducing cognitive decline and increased longevity are ongoing. However, it is widely agreed that the long-term effects of taking exogenous melatonin have been insufficiently studied and warrant additional investigation.

Adverse events in long-term studies of exogenous melatonin

INTRODUCTION

Exogenous melatonin is regulated as a drug in the UK and EU but is available as an over-the-counter dietary supplement in the US and Canada. In the last 15 years, melatonin use has increased rapidly in many countries, in particular, in children and adolescents who frequently have many years of continuous exposure. Despite this, the potential risks associated with extended use continue to be unclear, and there remains a lack of systematically assessed safety data from long-term prospective trials.

AREAS COVERED

This review focuses on adverse event data reported in long-term (≥6 months) prospective trials of melatonin.

METHODS

The Embase and Medline electronic databases were searched from inception to 12 September 2022 for long-term studies of melatonin, in which adverse events were systematically monitored and reported.

EXPERT OPINION

Although the reported frequency of possible adverse events associated with long-term melatonin use is low and few clinically significant adverse events have been reported, the scarcity of data from double-blind randomized placebo-controlled trials should caution against complacency. Ideally, analysis of data from large well-established research databases should be conducted to provide good quality evidence on which to base a more rigorous evaluation of the safety profile.

Melatonin Treatment for Pediatric Patients with Insomnia: Is There a Place for It?

Sleep is a vital physiological function that is impaired in ranges from 10% in the typically developing pediatric population to over 80% in populations of children with neurodevelopmental disorders and/or psychiatric comorbidities. Pediatric insomnia disorder is an increasing public health concern given its negative impact on synaptic plasticity involved in learning and memory consolidation but also on mood regulation, hormonal development and growth, and its significant impact on quality of life of the child, the adolescent and the family. While first-line treatment of pediatric insomnia should include parental education on sleep as well as sleep hygiene measures and behavioural treatment approaches, pharmacological interventions may be necessary if these strategies fail. Melatonin treatment has been increasingly used off-label in pediatric insomnia, given its benign safety profile. This article aims to identify the possible role of melatonin treatment for pediatric insomnia, considering its physiological role in sleep regulation and the differential effects of immediate release (IR) versus prolonged release (PR) melatonin. For the physician dealing with pediatric insomnia, it is particularly important to be able to distinguish treatment rationales implying different dosages and times of treatment intake. Finally, we discuss the benefit-risk ratio for melatonin treatment in different pediatric populations, ranging from the general pediatric population to children with different types of neurodevelopmental disorders, such as autism spectrum disorder or ADHD.

What do we really know about the safety and efficacy of melatonin for sleep disorders?

Melatonin is a hormonal product of the pineal gland, a fact that is often forgotten. Instead it is promoted as a dietary supplement that will overcome insomnia, as an antioxidant and as a prescription only drug in most countries outside the United States of America and Canada. The aim of this review is to step back and highlight what we know about melatonin following its discovery 60 years ago. What is the role of endogenous melatonin; what does melatonin do to sleep, body temperature, circadian rhythms, the cardiovascular system, reproductive system, endocrine system and metabolism when administered to healthy subjects? When used as a drug/dietary supplement, what safety studies have been conducted? Can we really say melatonin is safe when it has not been systematically studied and many studies show interactions with a wide range of physiological processes? Finally the results of studies investigating the efficacy of melatonin as a drug to alleviate insomnia are critically evaluated. In summary, melatonin is an endogenous pineal gland hormone with specific physiological functions in animals and humans, with its primary role in humans to maintain synchrony of sleep with the day/night cycle. When administered as a drug it affects a wide range of physiological systems and has clinically important drug interactions. With respect to efficacy for treating sleep disorders, melatonin can advance the time of sleep onset but the effect is modest and variable. In children with neurodevelopmental disabilities melatonin appears to have the greatest impact on sleep onset but little effect on sleep efficiency.

Pediatric use of prescribed melatonin in Sweden 2006-2017: a register based study

Sleep disturbances are common in the pediatric population and should primarily be treated non-pharmacologically. Most medicines for sleep disturbances are not approved for pediatric use and data on long-term safety is scarce. In Sweden, melatonin is classified as a prescription medicine. The aim of the present study was to characterize the prevalence and incidence of dispensed melatonin prescriptions, long-term treatment, concomitant dispensation of psychotropic medication, and psychiatric comorbidity, in children and adolescents aged 0-17 years living in Sweden during 2006-2017. Data was retrieved by linking the national population-based registers, the Swedish Prescribed Drug register and the National Patient register. In 2017, nearly 2% of the pediatric population 0-17 years was dispensed at least one prescription of melatonin, which was more than a 15-fold increase for girls and a 20-fold increase for boys, when compared to 2006. Among the children in the age group 5-9 who initiated a melatonin treatment in 2009, 15% of girls and 17% of boys were found to be continuously prescribed melatonin 8 years later. Nearly 80% of all children with dispensed melatonin had concomitant dispensations of psychotropic medications. The most common combination was melatonin together with centrally acting sympathomimetic medicines (23% of girls and 43% of boys). About half of the children (47% of girls and 50% of boys) had at least one registered diagnosis of mental or behavioral disorders. The most common diagnosis was attention deficit hyperactive disorder, across all age groups and genders. The continuous increase of use of melatonin in children, often concomitant with other psychotropic medications, together with a high proportion of younger children with prescriptions of melatonin on a long-term basis, suggests the need for further structured follow up studies, in particular of long-term use.

Myths and Evidence Regarding Melatonin Supplementation for Occasional Sleeplessness in the Pediatric Population

Occasional sleeplessness in children is common, with as many as 25% of all healthy children experiencing a problem sleeping at some point over the course of their childhood. Occasional sleeplessness is poorly understood, has a significant impact on quality of life in children and their families, and is often challenging to manage. There is substantial evidence supporting the safe and effective use of the widely available dietary supplement melatonin for children with chronic conditions. This article summarizes the views expressed in a recent Consensus Panel meeting convened to evaluate the use of melatonin in children, as well as the published scientific literature related to the effectiveness and safety of melatonin, with a focus on occasional sleeplessness in healthy children. We provide an evidence-based framework for the implementation of a standard process to effectively manage occasional sleeplessness in children and adolescents. Unsubstantiated concerns in the past may have limited melatonin's use in children with conditions for which the supplement may support a better sleep pattern and, by doing so, may help to improve quality of life. Melatonin dietary supplements using high quality standards may be provided to children together with cognitive-behavioral therapy after proper sleep evaluation and after improved sleep hygiene, family education, and sleep diary activities have failed to resolve sleep difficulties. [Pediatr Ann. 2021;50(9):e391-e395.].

Sleep and Puberty

In the 1970's, Boyar and colleagues made the seminal observation that during the early stages of puberty, there is a sleep-specific augmentation of pulsatile luteinizing hormone (LH) secretion. Building on this tantalizing association between sleep and the re-awakening of the neuro-reproductive axis, a number of investigators have since mapped the dynamic relationship between sleep and reproductive hormones across the pubertal transition. In this review, we focus on the complex, reciprocal relationship between sleep and reproductive hormones during adolescence as well as the potential effects of melatonin and orexin on gonadotropin-releasing hormone (GnRH) activity in children with chronic insomnia and narcolepsy, respectively. Given the important interaction between the reproductive and somatotropic axes during puberty, we end with a discussion of sleep and growth hormone (GH) secretion in children.

Intraindividual Variability and Temporal Stability of Mid-Sleep on Free and Workdays

People differ in their sleep timings that are often referred to as a chronotype and can be operationalized as mid-sleep (midpoint between sleep onset and wake-up). The aims of the present studies were to examine intraindividual variability and longer-term temporal stability of mid-sleep on free and workdays, while also considering the effect of age. We used data from a 2-week experience sampling study of British university students (Study 1) and from a panel study of Estonian adults who filled in the Munich Chronotype Questionnaire twice up to 5 years apart (Study 2). Results of Study 1 showed that roughly 50% of the variance in daily mid-sleep scores across the 14-day period was attributed to intraindividual variability as indicated by the intraclass correlation coefficient. However, when the effect of free versus workdays was considered, the intraindividual variability in daily mid-sleep across 2 weeks was 0.71 the size of the interindividual variability. In Study 2, mid-sleep on free and workdays showed good levels of temporal stability-the retest correlations of mid-sleep on free and workdays were 0.66 and 0.58 when measured twice over a period of 0-1 to 5 years. The retest stability of mid-sleep scores on both free and workdays sharply increased from young adulthood and reached their peak when participants were in late 40 to early 50 years of age, indicating that age influences the stability of mid-sleep. Future long-term longitudinal studies are necessary to explore how age-related life circumstances and other possible factors may influence the intraindividual variability and temporal stability of mid-sleep.

Sleep, Growth, and Puberty After 2 Years of Prolonged-Release Melatonin in Children With Autism Spectrum Disorder

OBJECTIVE

A recent 3-month double-blind, placebo-controlled study demonstrated efficacy and safety of pediatric prolonged-release melatonin (PedPRM) for insomnia in children with autism spectrum disorder. This study examined the long-term effects of PedPRM treatment on sleep, growth, body mass index, and pubertal development.

METHOD

Eighty children and adolescents (2-17.5 years of age; 96% with autism spectrum disorder) who completed the double-blind, placebo-controlled trial were given 2 mg, 5 mg, or 10 mg PedPRM nightly up to 104 weeks, followed by a 2-week placebo period to assess withdrawal effects.

RESULTS

Improvements in child sleep disturbance and caregiver satisfaction with child sleep patterns, quality of sleep, and quality of life were maintained throughout the 104-week treatment period (p < .001 versus baseline for all). During the 2-week withdrawal placebo period, measures declined compared with the treatment period but were still improved compared with baseline. PedPRM was generally safe; the most frequent treatment-related adverse events were fatigue (6.3%), somnolence (6.3%), and mood swings (4.2%). Changes in mean weight, height, body mass index, and pubertal status (Tanner staging done by a physician) were within normal ranges for age with no evidence of delay in body mass index or pubertal development.

CONCLUSION

Nightly PedPRM at optimal dose (2, 5, or 10 mg nightly) is safe and effective for long-term treatment in children and adolescents with autism spectrum disorder and insomnia. There were no observed detrimental effects on children's growth and pubertal development and no withdrawal or safety issues related to the use or discontinuation of the drug.

CLINICAL TRIAL REGISTRATION INFORMATION

Efficacy and Safety of Circadin in the Treatment of Sleep Disturbances in Children With Neurodevelopment Disabilities; https://clinicaltrials.gov/; NCT01906866.

Effect of Chronotype on Sleep Quality in a Laboratory Setting

Sleep is undoubtedly important for human health as insufficient sleep has been associated with a plethora of diseases. Adequate sleep assessment is critical in clinical and research settings, however current sleep assessment protocols fail to account for circadian rhythms, despite the fact that sleep is a well-recognized circadian process.

PURPOSE

The purpose of this study was to determine if circadian parameters, such as chronotype, influence sleep quality in a sleep laboratory setting.

METHODS

In order to investigate this, twenty participants (10 men and 10 women) aged 18-31 years old had their sleep recorded by electroencephalography in a sleep lab. Participants also complete surveys which provided data on chronotype, social jet lag and subjective sleep quality. Participants were allowed to self-select sleep time for the study, and sleep discrepancy, defined as the difference between reported and experienced mid-sleep, was determined.

RESULTS

Interestingly, results indicated a significant correlation between self-reported sleep quality and social jet lag, with those who typically experience more social jet lag being more satisfied with their sleep during the study (r = 0.549, p = 0.012). In addition, when participants were separated into groups based on chronotype, sleep discrepancy and social jet lag, sizeable differences were noted for parameters such as sleep onset latency, number of awakenings, and percent of time spent in REM sleep.

CONCLUSION

These results suggest circadian parameters serve as predictors of both subjective and objective sleep quality, and thus illuminates a necessity for these parameters to be taken into account in the assessment and research of sleep.

Efficacy and safety of supplemental melatonin for delayed sleep-wake phase disorder in children: an overview

Delayed sleep–wake phase disorder (DSPD) is the most frequently occurring intrinsic circadian rhythm sleep–wake disorder, with the highest prevalence in adolescence. Melatonin is the first-choice drug treatment. However, to date melatonin (in a controlled-release formulation) is only authorised for the treatment of insomnia in children with autism or Smiths-Magenis syndrome. Concerns have been raised with respect to the safety and efficacy of melatonin for more general use in children, as melatonin has not undergone the formal safety testing required for a new drug, especially long-term safety in children. Melatonin is known to have profound effects on the reproductive systems of rodents, sheep and primates, as well as effects on the cardiovascular, immune and metabolic systems.

The objective of the present article was therefore to establish the efficacy and safety of exogenous melatonin for use in children with DSPD, based on in vitro, animal model and clinical studies by reviewing the relevant literature in the Medline database using PubMed.

Acute toxicity studies in rats and mice showed toxic effects only at extremely high melatonin doses (>400 mg/kg), some tens of thousands of times more than the recommended dose of 3–6 mg in a person weighing 70 kg. Longer-term administration of melatonin improved the general health and survival of ageing rats or mice. A full range of in vitro/in vivo genotoxicity tests consistently found no evidence that melatonin is genotoxic. Similarly long term administration of melatonin in rats or mice did not have carcinogenic effects, or negative effects on cardiovascular, endocrine and reproductive systems.

With regard to clinical studies, in 19 randomised controlled trials comprising 841 children and adolescents with DSPD, melatonin treatment (usually of 4 weeks duration) consistently improved sleep latency by 22–60 min, without any serious adverse effects. Similarly, 17 randomised controlled trials, comprising 1374 children and adolescents, supplementing melatonin for indications other than DSPD, reported no relevant adverse effects. In addition, 4 long-term safety studies (1.0–10.8 yr) supplementing exogenous melatonin found no substantial deviation of the development of children with respect to sleep quality, puberty development and mental health scores. Finally, post-marketing data for an immediate-release melatonin formulation (Bio-melatonin), used in the UK since 2008 as an unlicensed medicine for sleep disturbance in children, recorded no adverse events to date on sales of approximately 600,000 packs, equivalent to some 35 million individual 3 mg tablet doses (MHRA yellow card adverse event recording scheme).

In conclusion, evidence has been provided that melatonin is an efficacious and safe chronobiotic drug for the treatment of DSPD in children, provided that it is administered at the correct time (3–5 h before endogenous melatonin starts to rise in dim light (DLMO)), and in the correct (minimal effective) dose. As the status of circadian rhythmicity may change during long-time treatment, it is recommended to stop melatonin treatment at least once a year (preferably during the summer holidays).

•

Melatonin improves sleep onset without serious adverse effects in youths with DSPD. Change th text after the fourth bullet into: Melatonin is an efficacious and safe chronobiotic drug for the treatment of DSPD in youths.

•

Melatonin for indications other than DSPD, dose not cause relevant adverse effects.

•

Long term melatonin treatment does not impair sleep, puberty, and mental health.

•

Melatonin is an efficacious and safe chronobiotic drug for the treatment of DSPD in youths.

•

Melatonin should be administered at the correct time and in the minimal effective dose.

The association between sleep duration, bedtimes, and early pubertal timing among Chinese adolescents: a cross-sectional study

BACKGROUND AND OBJECTIVE

Early pubertal timing is associated with sleep among Western adolescents, but little is known about this association in Chinese adolescents, especially with regard to the association between bedtimes and early pubertal timing. This paper aimed to identify the association between sleep duration, bedtimes, and early pubertal timing in Chinese adolescents.

METHODS

An anonymous cross-sectional survey was conducted among primary and junior middle students (grades 3 to 9) from QiJiang District, ChongQing, China. Participants were recruited by applying stratified cluster sampling. Pubertal timing, sleep duration, and bedtimes were assessed using the Pubertal Development Scale and a self-designed sleep questionnaire. We utilized multivariable logistic linear regression (MLLR) to test the association between sleep duration, bedtimes, and pubertal timing.

RESULTS

A total of 5461 adolescents were evaluated, with mean age and BMI values of 11.41 ± 2.05 and 18.03 ± 3.03, respectively, of whom 1257 (23.02%) were in early pubertal timing. In MLLR controlling for age, BMI, family economic status, and other covariates, sufficient sleep (b = - 0.214, P = 0.032, OR = 0.808, 95% CI 0.664-0.982) was negatively related to early pubertal timing, and later bedtime (b = 0.195, P < 0.001, OR = 1.215, 95% CI 1.104-1.338) was positively associated with early pubertal timing.

CONCLUSION

Students with early pubertal timing had less sleep duration and later bedtimes, which may be the result of increased stress caused by physical and psychological changes. Therefore, more attention should be paid to pubertal health education for adolescents during puberty. Further longitudinal studies are needed to confirm the causality between sleep and early pubertal timing in Chinese adolescents.

Role of biological rhythm dysfunction in the development and management of bipolar disorders: a review

Disturbance of biological rhythms contributes to the onset of bipolar disorders and is an important clinical feature of the condition. To further explore the role of biological rhythms in bipolar disorders, 95 English articles published between 1968 and 2019 were retrieved from the PubMed database and analysed. We herein review the outcomes of studies on biological rhythm disturbance in bipolar disorders, including the epidemiology, aetiology, clinical features (eg, sleep, feeding and eating disorders) and treatment of the condition evaluated by patients’ self-report and biological indicators such as melatonin. Our report supports the characterisation of biological rhythm disturbance as a significant clinical feature affecting the onset and development of bipolar disorders and reviews classical and novel treatments, such as chronotherapy, that can be applied in the clinical practice. Our analysis indicates that a more comprehensive study of the pathophysiology, clinical phenomenology and treatment of biological rhythm disturbance is required.

Adverse Events Associated with Melatonin for the Treatment of Primary or Secondary Sleep Disorders: A Systematic Review

BACKGROUND

Melatonin is widely available either on prescription for the treatment of sleep disorders or as an over-the-counter dietary supplement. Melatonin has also recently been licensed in the UK for the short-term treatment of jetlag. Little is known about the potential for adverse events (AEs), in particular AEs resulting from long-term use. Concern has been raised over the possible risks of exposure in certain populations including pre-adolescent children and patients with epilepsy or asthma.

OBJECTIVES

The aim of this systematic review was to assess the evidence for AEs associated with short-term and longer-term melatonin treatment for sleep disorders.

METHODS

A literature search of the PubMed/Medline database and Google Scholar was conducted to identify randomised, placebo-controlled trials (RCTs) of exogenous melatonin administered for primary or secondary sleep disorders. Studies were included if they reported on both the types and frequencies of AEs. Studies of pre-term infants, studies of < 1 week in duration or involving single doses of melatonin and studies in languages other than English were excluded. Findings from open-label studies that raised concerns relating to AE reports in patients were also examined. Studies were assessed for quality of reporting against the Consolidated Standards of Reporting Trials (CONSORT) checklist and for risk of bias against the Cochrane Collaboration risk-of-bias criteria.

RESULTS

37 RCTs met criteria for inclusion. Daily melatonin doses ranged from 0.15 mg to 12 mg. Subjects were monitored for up to 29 weeks, but most studies were of much shorter duration (4 weeks or less). The most frequently reported AEs were daytime sleepiness (1.66%), headache (0.74%), other sleep-related AEs (0.74%), dizziness (0.74%) and hypothermia (0.62%). Very few AEs considered to be serious or of clinical significance were reported. These included agitation, fatigue, mood swings, nightmares, skin irritation and palpitations. Most AEs either resolved spontaneously within a few days with no adjustment in melatonin, or immediately upon withdrawal of treatment. Melatonin was generally regarded as safe and well tolerated. Many studies predated publication of the CONSORT checklist and consequently did not conform closely to the guidelines. Similarly, only eight studies were judged 'good' overall with respect to the Cochrane risk-of-bias criteria. Of the remaining papers, 16 were considered 'fair' and 13 'poor' but publication of almost half of the papers preceded that of the earliest version of the guidelines.

CONCLUSION

Few, generally mild to moderate, AEs were associated with exogenous melatonin. No AEs that were life threatening or of major clinical significance were identified. The scarcity of evidence from long-term RCTs, however, limits the conclusions regarding the safety of continuous melatonin therapy over extended periods. There are insufficient robust data to allow a meaningful appraisal of concerns that melatonin may result in more clinically significant adverse effects in potentially at-risk populations. Future studies should be designed to comply with appropriate quality standards for RCTs, which most past studies have not.

Efficacy and safety of melatonin for sleep onset insomnia in children and adolescents: a meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the efficacy and safety of melatonin in the treatment of sleep onset insomnia in children and adolescents.

METHODS

Electronic databases and bibliographies of relevant reports were searched for randomized, placebo-controlled, clinical trials that used melatonin in children and adolescents with sleep onset insomnia. The quality of the included studies was assessed by the Cochrane Collaboration's risk-of-bias method. The mean differences (MD) and the odds ratios (OR) with 95% confidence interval (CI) were estimated by a random-effects model. Primary outcomes were sleep onset time (SOT), drop-out for all causes and drop-out for adverse events. Secondary outcomes included dim light melatonin onset (DLMO), sleep onset latency (SOL), total sleep time (TST), light-off time, and wake-up time.

RESULTS

Seven trials with 387 participants were finally included after a systematic search. The overall quality of the included studies was low to moderate. SOT in patients receiving melatonin advanced more than patients receiving placebo (MD = -0.62 h, 95% CI -0.80, -0.45), as well as DLMO (MD = -0.82 h, 95% CI -1.23, -0.41). No differences were found in the outcome of drop-out for all causes (OR = 1.51, 95% CI 0.57, 4.05) or drop-out for adverse events (OR = 3.35, 95% CI 0.13, 86.03). Severe adverse events, migraine, and mild generalized epilepsy were reported in two cases. SOL decreased and TST increased, MD = -0.36 h (95% CI -0.49, -0.24) and MD = 0.38 h (95% CI 0.09, 0.66), respectively. Light-off time and wake-up time did not differ significantly.

CONCLUSIONS

Melatonin was an effective and tolerable drug in the short-term treatment of sleep onset insomnia in children and adolescents. More studies, especially in adolescents, are needed to investigate the efficacy and safety of melatonin.

Could long-term administration of melatonin to prepubertal children affect timing of puberty? A clinician's perspective

Exogenous melatonin can be used to treat sleep disturbance in adults, children, and adolescents. While its short-term use is considered safe, there are some concerns that long-term use might delay children's sexual maturation, possibly by disrupting the decline in nocturnal melatonin levels that occur at the onset of puberty. This narrative review aimed to summarize some of the current knowledge about the potential effects of exogenous melatonin on puberty. We found no clinical studies that experimentally tested the effects of melatonin on pubertal timing in children, but we reviewed the small number of observational studies. We also drew on animal data to try to answer our question. The photoperiod and melatonin-mediated seasonal transitions in sexual activity and breeding in some mammals across the seasons have been used as a model of sexual development in mammals, including humans. The switch from non-sexual activity (in the non-breeding period) to sexual activity (in the breeding period) has been likened to the onset of puberty as there are similarities between the two. We conclude that to investigate an association between melatonin and pubertal timing, it will be important to conduct long-term randomized controlled trials of latency age children and also examine the cellular and systems-level interactions between melatonin and kisspeptin, a recently identified neuropeptide with a locus of action at the gonadotropin releasing hormone neurons that is important in contributing to the timing of puberty onset.