A randomized controlled trial with bright light and melatonin for the treatment of delayed sleep phase disorder: effects on subjective and objective sleepiness and cognitive function

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.

Updates and confounding factors in delayed sleep-wake phase disorder

Delayed sleep-wake phase disorder (DSWPD) is a circadian rhythm sleep disorder characterised by a delay in the main sleep period, with patients experiencing difficulty getting to sleep and waking up at socially appropriate times. This often causes insomnia and compromised sleep, results in impairment to daytime function and is associated with a range of comorbidities. Besides interventions aimed at ameliorating symptoms, there is good evidence supporting successful phase advancement with bright light therapy or melatonin administration. However, no treatment to date addresses the tendency to phase delay, which is a common factor amongst the various contributing causes of DSWPD. Circadian phase markers such as core body temperature and circulating melatonin typically correlate well with sleep timing in healthy patients, but numerous variations exist in DSWPD patients that can make these unpredictable for use in diagnostics. There is also increasing evidence that, on top of problems with the circadian cycle, sleep homeostatic processes actually differ in DSWPD patients compared to controls. This naturally has ramifications for management but also for the current approach to the pathogenesis itself in which DSWPD is considered a purely circadian disorder. This review collates what is known on the causes and treatments of DSWPD, addresses the pitfalls in diagnosis and discusses the implications of current data on modified sleep homeostasis, making clinical recommendations and directing future research.

Non-pharmacological interventions for sleep disturbances in people with dementia

BACKGROUND

Sleep disturbances occur frequently in people with dementia with a reported prevalence of up to 40%. Common problems are increased number and duration of awakenings and increased percentage of light sleep. Sleep disturbances are associated with a number of problems for people with dementia, their relatives, and carers. In people with dementia, they may lead to worsening of cognitive symptoms, challenging behaviours such as restlessness or wandering, and further harms, such as accidental falls. Sleep disturbances are also associated with significant carer distress and have been reported as a factor contributing to institutionalisation of people with dementia. As pharmacological approaches have shown unsatisfactory results, there is a need to synthesise the research evidence on non-pharmacological strategies to improve sleep in people with dementia. As interventions are often complex, consisting of more than one active component, and implemented in complex contexts, it may not be easy to identify effective intervention components.

OBJECTIVES

To evaluate the benefits and harms of non-pharmacological interventions on sleep disturbances in people with dementia compared to usual care, no treatment, any other non-pharmacological intervention, or any drug treatment intended to improve sleep, and to describe the components and processes of any complex intervention included.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search was 13 January 2022.

SELECTION CRITERIA

We included individually or cluster-randomised controlled trials in people with dementia comparing non-pharmacological interventions to improve sleep compared to usual care or to other interventions of any type. Eligible studies had to have a sleep-related primary outcome. We included people with a diagnosis of dementia and sleep problems at baseline irrespective of age, type of dementia, severity of cognitive impairment, or setting. Studies reporting results on a mixed sample (e.g. in a nursing home) were only considered for inclusion if at least 80% of participants had dementia.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. objective sleep-related outcomes (e.g. total nocturnal sleep time, consolidated sleep time at night, sleep efficiency, total wake time at night (or time spent awake after sleep onset), number of nocturnal awakenings, sleep onset latency, daytime/night-time sleep ratio, night-time/total sleep ratio over 24 hours) and 2.

ADVERSE EVENTS

Our secondary outcomes were 3. subjective sleep-related outcomes, 4. behavioural and psychological symptoms of dementia, 5. quality of life, 6. functional status, 7. institutionalisation, 8. compliance with the intervention, and 9. attrition rates. We used GRADE to assess the certainty of evidence and chose key outcomes to be included in summary of findings tables.

MAIN RESULTS

We included 19 randomised controlled trials with 1335 participants allocated to treatment or control groups. Fourteen studies were conducted in nursing homes, three included community residents, one included 'inpatients', one included people from a mental health centre, and one included people from district community centres for older people. Fourteen studies were conducted in the US. We also identified nine ongoing studies. All studies applied one or more non-pharmacological intervention aiming to improve physiological sleep in people with dementia and sleep problems. The most frequently examined single intervention was some form of light therapy (six studies), five studies included physical or social activities, three carer interventions, one daytime sleep restriction, one slow-stroke back massage, and one transcranial electrostimulation. Seven studies examined multimodal complex interventions. Risk of bias of included studies was frequently unclear due to incomplete reporting. Therefore, we rated no study at low risk of bias. We are uncertain whether light therapy has any effect on sleep-related outcomes (very low-certainty evidence). Physical activities may slightly increase the total nocturnal sleep time and sleep efficiency, and may reduce the total time awake at night and slightly reduce the number of awakenings at night (low-certainty evidence). Social activities may slightly increase total nocturnal sleep time and sleep efficiency (low-certainty evidence). Carer interventions may modestly increase total nocturnal sleep time, may slightly increase sleep efficiency, and may modestly decrease the total awake time during the night (low-certainty evidence from one study). Multimodal interventions may modestly increase total nocturnal sleep time and may modestly reduce the total wake time at night, but may result in little to no difference in number of awakenings (low-certainty evidence). We are uncertain about the effects of multimodal interventions on sleep efficiency (very low-certainty evidence). We found low-certainty evidence that daytime sleep restrictions, slow-stroke back massage, and transcranial electrostimulation may result in little to no difference in sleep-related outcomes. Only two studies reported information about adverse events, detecting only few such events in the intervention groups.

AUTHORS' CONCLUSIONS

Despite the inclusion of 19 randomised controlled trials, there is a lack of conclusive evidence concerning non-pharmacological interventions for sleep problems in people with dementia. Although neither single nor multimodal interventions consistently improved sleep with sufficient certainty, we found some positive effects on physical and social activities as well as carer interventions. Future studies should use rigorous methods to develop and evaluate the effectiveness of multimodal interventions using current guidelines on the development and evaluation of complex interventions. At present, no single or multimodal intervention can be clearly identified as suitable for widespread implementation.

Effect of melatonin on quality of life and symptoms in patients with cancer: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

This study systematically reviewed the effect of melatonin (MLT) on quality of life (QoL) and symptoms among patients with cancer.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Cochrane Library, PubMed, Embase, Web of Science, Medline, CINAHL, Scopus, ClinicalTrials.gov, China Biology Medicine (CBM), ProQuest and Open Grey were searched from inception to November 2021.

ELIGIBILITY CRITERIA

We included randomised controlled trials (RCTs) assessing the effects of MLT on QoL, sleep quality, fatigue, depression, pain, stomatitis rate and stomatitis severity in adult patients with cancer, without language restrictions. Studies that reported the effects of MLT along with other interventions and had incomplete or absent outcome data were excluded.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data, and another two reviewers assessed the risk of bias. The risk of bias for each eligible study was assessed using the Cochrane assessment tool. The mean difference or standard mean difference (SMD) with 95% CIs was used in the computation of continuous variables to synthesise data. The relative risk was used for dichotomous outcomes. Heterogeneity was assessed and quantified (I² statistic).

RESULTS

A total of 19 qualified studies that included 2101 patients with cancer (MLT: 1078, control: 1023) were included in the meta-analysis. The results indicated that MLT had no significant effect on QoL (SMD=-0.01, 95% CI (-0.14 to 0.11), p=0.83), sleep quality (SMD=-0.18, 95% CI (-0.62 to 0.26), p=0.42), fatigue (SMD=-0.34, 95% CI (-0.73 to 0.06), p=0.10), pain (SMD=-0.34, 95% CI (-0.7 to 0.02), p=0.06) or stomatitis severity (RR=0.78, 95% CI (0.47 to 1.30), p=0.35). MLT reduced stomatitis rate among patients with cancer (RR=0.47, 95% CI (0.26 to 0.88), p=0.02), except those with head and neck cancer (RR=1.09, 95% CI (0.92 to 1.29), p=0.35). MLT eased depression in patients who received administration for more than 14 days (SMD=-0.14, 95% CI (-0.27 to -0.01), p=0.03) and those who underwent surgery (SMD=-0.17, 95% CI (-0.32 to -0.03), p=0.02).

CONCLUSION

The findings showed that MLT did not improve the QoL, sleep quality, fatigue, pain or stomatitis severity among patients with cancer. It had a limited effect on decreasing the stomatitis rate and easing depression. Different treatments, durations and cancer types were the main sources of heterogeneity. Further large-scale RCTs are urgently needed. In addition, the effects of different combinations of MLT dosage and duration, administration types and joint measures are worthy of further study.

PROSPERO REGISTRATION NUMBER

CRD42021292855.

Circadian Regulation of Hormonal Timing and the Pathophysiology of Circadian Dysregulation

Circadian rhythms are endogenously generated, daily patterns of behavior and physiology that are essential for optimal health and disease prevention. Disruptions to circadian timing are associated with a host of maladies, including metabolic disease and obesity, diabetes, heart disease, cancer, and mental health disturbances. The circadian timing system is hierarchically organized, with a master circadian clock located in the suprachiasmatic nucleus (SCN) of the anterior hypothalamus and subordinate clocks throughout the CNS and periphery. The SCN receives light information via a direct retinal pathway, synchronizing the master clock to environmental time. At the cellular level, circadian rhythms are ubiquitous, with rhythms generated by interlocking, autoregulatory transcription-translation feedback loops. At the level of the SCN, tight cellular coupling maintains rhythms even in the absence of environmental input. The SCN, in turn, communicates timing information via the autonomic nervous system and hormonal signaling. This signaling couples individual cellular oscillators at the tissue level in extra-SCN brain loci and the periphery and synchronizes subordinate clocks to external time. In the modern world, circadian disruption is widespread due to limited exposure to sunlight during the day, exposure to artificial light at night, and widespread use of light-emitting electronic devices, likely contributing to an increase in the prevalence, and the progression, of a host of disease states. The present overview focuses on the circadian control of endocrine secretions, the significance of rhythms within key endocrine axes for typical, homeostatic functioning, and implications for health and disease when dysregulated. © 2022 American Physiological Society. Compr Physiol 12: 1-30, 2022.

Electric lighting, adolescent sleep and circadian outcomes, and recommendations for improving light health

Light is a potent circadian entraining agent. For many people, daily light exposure is fundamentally dysregulated with reduced light during the day and increased light into the late evening. This lighting schedule promotes chronic disruption to circadian physiology resulting in a myriad of impairments. Developmental changes in sleep-wake physiology suggest that such light exposure patterns may be particularly disruptive for adolescents and further compounded by lifestyle factors such as early school start times. This narrative review describes evidence that reduced light exposure during the school day delays the circadian clock, and longer exposure durations to light-emitting electronic devices in the evening suppress melatonin. While home lighting in the evening can suppress melatonin secretion and delay circadian phase, the patterning of light exposure across the day and evening can have moderating effects. Photic countermeasures may be flexibly and scalably implemented to support sleep-wake health; including manipulations of light intensity, spectra, duration and delivery modality across multiple contexts. An integrative approach addressing physiology, attitudes, and behaviors will support optimization of light-driven sleep-wake outcomes in adolescents.

Sleep's role in the development and resolution of adolescent depression

Two adolescent mental health fields - sleep and depression - have advanced largely in parallel until about four years ago. Although sleep problems have been thought to be a symptom of adolescent depression, emerging evidence suggests that sleep difficulties arise before depression does. In this Review, we describe how the combination of adolescent sleep biology and psychology uniquely predispose adolescents to develop depression. We describe multiple pathways and contributors, including a delayed circadian rhythm, restricted sleep duration and greater opportunity for repetitive negative thinking while waiting for sleep. We match each contributor with evidence-based sleep interventions, including bright light therapy, exogenous melatonin and cognitive-behaviour therapy techniques. Such treatments improve sleep and alleviate depression symptoms, highlighting the utility of sleep treatment for comorbid disorders experienced by adolescents.

Adjunctive bright light treatment with gradual advance in unipolar major depressive disorder with evening chronotype - A randomized controlled trial

BACKGROUND

Unipolar non-seasonal depressed patients with concomitant evening chronotype were associated with poor clinical outcomes and higher non-remission rate. This study aims to examine the efficacy of adjunctive bright light therapy with gradual timing advance in a randomized, assessor and prescriber-blinded controlled trial.

METHOD

Participants were randomly allocated to receive 5 weeks of either bright white light therapy (BLT) or dim red light (DRL) with the same advancement protocol. Participants were followed up till 5 months after treatment. Primary outcomes included (i) remission rate and (ii) the severity of depression. The analysis was conducted using Kaplan-Meier survival analysis, Cox proportional hazard analysis and linear mixed models.

RESULTS

A total of 93 participants (46.4 ± 11.7 years old, 80% female) were randomized. The cumulative remission rate for the BLT and the DRL groups was 67.4% and 46.7%, respectively. Time to remission was shorter for the BLT group relative to the DRL group (log-rank test p = 0.024). Cox proportional hazard survival analysis showed that patients in the BLT group had a higher probability of achieving remission relative to patients in the DRL group [hazard ratio = 1.9 (95% CI = 1.1- 3.4), p = 0.026]. Further sensitivity analysis demonstrated greater improvement in 17-Hamilton Depression Score (group × time interaction, p = 0.04) in the BLT group for those who were adherent to light therapy.

CONCLUSIONS

The use of bright light therapy with gradual advance protocol is an effective adjunctive treatment resulting in quicker and a higher rate of remission of depression in patients with non-seasonal unipolar depression and evening-chronotype.

Pediatric Sleep Medicine Cases

Purpose of the Review

In this review, we will discuss commonly encountered pediatric sleep disorders, their clinical presentations, evaluation, and management.

Recent Findings

Sleep problems are common complaints in the pediatric population with an estimated prevalence of at least 25%. This review examines frequently seen pediatric sleep disorders including insomnia, obstructive sleep apnea, hypersomnolence, circadian rhythm sleep–wake disorders, parasomnias, and movement disorders. Their clinical manifestations vary, but left untreated, these sleep disorders result in significant impairment. A detailed sleep history is key component in the evaluation process. Other useful tools include sleep diaries, questionnaires, and actigraphy. Polysomnography is often required for diagnosis. Treatment varies depending on the underlying sleep disorder. Pharmacologic treatment is often limited due to the lack of studies of safety and efficacy in the pediatric population.

Summary

Sleep disorders are commonly encountered in the pediatric population. Their clinical manifestations vary, though without treatment, many result in significant impairment. Detailed sleep history is an essential part of the evaluation process, though polysomnography is often required. Treatment depends on the underlying diagnosis.

Understanding Sleep-Wake Behavior in Late Chronotype Adolescents: The Role of Circadian Phase, Sleep Timing, and Sleep Propensity

BACKGROUND

Adolescents with a late chronotype are at greater risk for mood disorders, risk-taking behaviors, school absenteeism, and lower academic achievement. As there are multiple causes for late chronotype, the field lacks studies on the relationship between mood, circadian phase, and phase angle of entrainment in late chronotype adolescents. Three objectives guide this explorative study: (1) to describe sleep, circadian phase, and phase angle of entrainment in late chronotype adolescents, (2) to explore how different levels of lateness are associated with sleep quality, sleep propensity, and mood, and (3) to investigate the influence of circadian phase on bedtime choice and sleep duration.

METHODS

Baseline data from 19 male adolescents (M = 16.4 ± 1.0 yrs), who were part of a larger intervention trial, were analyzed. Chronotype was measured with the Munich Chronotype Questionnaire, circadian timing via dim light melatonin onset (DLMO), and sleep habits with a 7-day sleep log. Further questionnaires assessed daytime sleepiness, sleep quality, and mood. Evening sleepiness and sustained attention were used as a proxy for evening sleep propensity.

RESULTS

On school nights, sleep duration averaged 7.78 h (±1.65), and 9.00 h (±1.42) on weekend nights. Mean DLMO was observed at 23.13 h (± 1.65), with a weekend phase angle of entrainment of 2.48 h. Regression fittings revealed a tendency for shorter phase angles with delayed DLMOs. Further analysis with chronotype subgroups revealed that this was only true for light and moderate late types, whereas extreme late types showed wide phase angles. Even though daytime sleepiness and sleep duration did not differ between subgroups, mood and sleep quality declined as lateness increased. Extreme late chronotypes experienced higher evening sleepiness, while slight late chronotypes showed higher evening attention. Chronotype but not DLMO predicted bedtime on school- and particularly weekend-nights.

CONCLUSIONS

Our findings suggest that with increasing lateness, the likelihood of experiencing poor sleep quality and mood disorders increases. As DLMO did not predict bedtime, our data indicate that the factors contributing to a late chronotype are versatile and complex, particularly for extreme late types. Further studies involving a larger and gender-balanced sample are needed to confirm findings.

Development of a Home-Based Light Therapy for Fatigue Following Traumatic Brain Injury: Two Case Studies

Background and Objectives: Fatigue and sleep disturbance negatively impact quality of life following brain injury and there are no established treatments. Building on research showing efficacy of blue light therapy delivered via a lightbox in reducing fatigue and daytime sleepiness after traumatic brain injury (TBI), this paper describes the development and implementation of a novel in-home light therapy to alleviate fatigue and sleep disturbance in two case studies. Methods: During the 8-week lighting intervention, participants' home lighting was adjusted to provide high intensity, blue-enriched (high melanopic) light all day as a stimulant and dimmer, blue-depleted (low melanopic) light for 3 h before sleep as a soporific. The sham 8-week control condition resembled participants' usual (baseline) lighting conditions (3,000-4,000 K all day). Lighting conditions were crossed-over. Outcomes were measures of fatigue, subjective daytime sleepiness, sleep quality, insomnia symptoms, psychomotor vigilance and mood. Case study participants were a 35-year old male (5 years post-TBI), and a 46-year-old female (22 years post-TBI). Results: The relative proportion of melanopic lux was greater in Treatment lighting than Control during daytime, and lower during evenings. Participants found treatment to be feasible to implement, and was well-tolerated with no serious side effects noted. Self-reported compliance was >70%. Both cases demonstrated reduced fatigue, sleep disturbance and insomnia symptoms during the treatment lighting intervention. Case 2 additionally showed reductions in daytime sleepiness and depressive symptoms. As expected, symptoms trended toward baseline levels during the control condition. Discussion: Treatment was positively received and compliance rates were high, with no problematic side-effects. Participants expressed interest in continuing the ambient light therapy in their daily lives. Conclusions: These cases studies demonstrate the acceptability and feasibility of implementing a personalized in-home dynamic light treatment for TBI patients, with evidence for efficacy in reducing fatigue and sleep disturbance. Clinical Trial Registration:www.anzctr.org.au, identifier: ACTRN12617000866303.

The evening light environment in hospitals can be designed to produce less disruptive effects on the circadian system and improve sleep

STUDY OBJECTIVES

Blue-depleted lighting reduces the disruptive effects of evening artificial light on the circadian system in laboratory experiments, but this has not yet been shown in naturalistic settings. The aim of the current study was to test the effects of residing in an evening blue-depleted light environment on melatonin levels, sleep, neurocognitive arousal, sleepiness, and potential side effects.

METHODS

The study was undertaken in a new psychiatric hospital unit where dynamic light sources were installed. All light sources in all rooms were blue-depleted in one half of the unit between 06:30 pm and 07:00 am (melanopic lux range: 7-21, melanopic equivalent daylight illuminance [M-EDI] range: 6-19, photopic lux range: 55-124), whereas the other had standard lighting (melanopic lux range: 30-70, M-EDI range: 27-63, photopic lux range: 64-136), but was otherwise identical. A total of 12 healthy adults resided for 5 days in each light environment (LE) in a randomized cross-over trial.

RESULTS

Melatonin levels were less suppressed in the blue-depleted LE (15%) compared with the normal LE (45%; p = 0.011). Dim light melatonin onset was phase-advanced more (1:20 h) after residing in the blue-depleted LE than after the normal LE (0:46 h; p = 0.008). Total sleep time was 8.1 min longer (p = 0.032), rapid eye movement sleep 13.9 min longer (p < 0.001), and neurocognitive arousal was lower (p = 0.042) in the blue-depleted LE. There were no significant differences in subjective sleepiness (p = 0.16) or side effects (p = 0.09).

CONCLUSIONS

It is possible to create an evening LE that has an impact on the circadian system and sleep without serious side effects. This demonstrates the feasibility and potential benefits of designing buildings or hospital units according to chronobiological principles and provide a basis for studies in both nonclinical and clinical populations.

Circadian tau differences and rhythm associations in delayed sleep-wake phase disorder and sighted non-24-hour sleep-wake rhythm disorder

STUDY OBJECTIVES

We investigated biological and behavioral rhythm period lengths (i.e. taus) of delayed sleep-wake phase disorder (DSWPD) and non-24-hour sleep-wake rhythm disorder (N24SWD). Based on circadian phase timing (temperature and dim light melatonin onset), DSWPD participants were dichotomized into a circadian-delayed and a circadian non-delayed group to investigate etiological differences.

METHODS

Participants with DSWPD (n = 26, 17 m, age: 21.85 ± 4.97 years), full-sighted N24SWD (n = 4, 3 m, age: 25.75 ± 4.99 years) and 18 controls (10 m, age: 23.72 ± 5.10 years) participated in an 80-h modified constant routine. An ultradian protocol of 1-h "days" in dim light, controlled conditions alternated 20-min sleep/dark periods with 40-min enforced wakefulness/light. Subjective sleepiness ratings were recorded prior to every sleep/dark opportunity and median reaction time (vigilance) was measured hourly. Obtained sleep (sleep propensity) was derived from 20-min sleep/dark opportunities to quantify hourly objective sleepiness. Hourly core body temperature was recorded, and salivary melatonin assayed to measure endogenous circadian rhythms. Rhythm data were curved using the two-component cosine model.

RESULTS

Patients with DSWPD and N24SWD had significantly longer melatonin and temperature taus compared to controls. Circadian non-delayed DSWPD had normally timed temperature and melatonin rhythms but were typically sleeping at relatively late circadian phases compared to those with circadian-delayed DSWPD.

CONCLUSIONS

People with DSWPD and N24SWD exhibit significantly longer biological circadian rhythm period lengths compared to controls. Approximately half of those diagnosed with DSWPD do not have abnormally delayed circadian rhythm timings suggesting abnormal phase relationship between biological rhythms and behavioral sleep period or potentially conditioned sleep-onset insomnia.

The efficacy of combined bright light and melatonin therapies on sleep and circadian outcomes: A systematic review

The aim of this systematic review was to investigate the effects of combined melatonin and bright light therapies on improved sleep and circadian outcomes. We conducted a systematic review that resulted in a total of eight papers meeting criteria. Four papers investigated the effectiveness of combined therapy in inducing a circadian phase shift on healthy participants. Combined therapy outperformed single light and melatonin therapies in phase advancing, but not in delaying, dim light melatonin onset (DLMO). The other four papers investigated the effect of combined therapy on sleep outcomes. Two of them were performed in elderly populations suffering from cognitive decline and two in delayed sleep-wake phase disorder (DSWPD) patients. While combined therapy was more beneficial than single therapy in elderly populations it did not show any benefit in DSWPD patients. The reported adverse effects of melatonin in elderly populations must be carefully considered. Future studies should investigate the separate and combined effect of melatonin and bright light on sleep and circadian outcomes in different target populations.

Insomnia - A Heterogenic Disorder Often Comorbid With Psychological and Somatic Disorders and Diseases: A Narrative Review With Focus on Diagnostic and Treatment Challenges

Patients with insomnia complain of problems with sleep onset or sleep maintenance or early morning awakenings, or a combination of these, despite adequate opportunity and circumstances for sleep. In addition, to fulfill the diagnostic criteria for insomnia the complaints need to be associated with negative daytime consequences. For chronic insomnia, the symptoms are required to be present at least 3 days per week for a duration of at least 3 months. Lastly, for insomnia to be defined as a disorder, the sleep complaints and daytime symptoms should not be better explained by another sleep disorder. This criterion represents a diagnostic challenge, since patients suffering from other sleep disorders often complain of insomnia symptoms. For instance, insomnia symptoms are common in e.g., obstructive sleep apnea and circadian rhythm sleep-wake disorders. It may sometimes be difficult to disentangle whether the patient suffers from insomnia disorder or whether the insomnia symptoms are purely due to another sleep disorder. Furthermore, insomnia disorder may be comorbid with other sleep disorders in some patients, e.g., comorbid insomnia and sleep apnea (COMISA). In addition, insomnia disorder is often comorbid with psychological or somatic disorders and diseases. Thus, a thorough assessment is necessary for correct diagnostics. For chronic insomnia disorder, treatment-of-choice is cognitive behavioral therapy, and such treatment is also effective when the insomnia disorder appears comorbid with other diagnoses. Furthermore, studies suggest that insomnia is a heterogenic disorder with many different phenotypes or subtypes. Different insomnia subtypes may respond differently to treatment, but more research on this issue is warranted. Also, the role of comorbidity on treatment outcome is understudied. This review is part of a Research Topic on insomnia launched by Frontiers and focuses on diagnostic and treatment challenges of the disorder. The review aims to stimulate to more research into the bidirectional associations and interactions between insomnia disorder and other sleep, psychological, and somatic disorders/diseases.

A PERIOD3 variable number tandem repeat polymorphism modulates melatonin treatment response in delayed sleep-wake phase disorder

We examined whether a polymorphism of the PERIOD3 gene (PER3; rs57875989) modulated the sleep-promoting effects of melatonin in Delayed Sleep-Wake Phase Disorder (DSWPD). One hundred and four individuals (53 males; 29.4 ±10.0 years) with DSWPD and a delayed dim light melatonin onset (DLMO) collected buccal swabs for genotyping (PER3^4/4 n = 43; PER3 5 allele [heterozygous and homozygous] n = 60). Participants were randomised to placebo or 0.5 mg melatonin taken 1 hour before desired bedtime (or ~1.45 hours before DLMO), with sleep attempted at desired bedtime (4 weeks; 5-7 nights/week). We assessed sleep (diary and actigraphy), Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Patient-Reported Outcomes Measurement Information System (PROMIS: Sleep Disturbance, Sleep-Related Impairment), Sheehan Disability Scale (SDS) and Patient- and Clinician-Global Improvement (PGI-C, CGI-C). Melatonin treatment response on actigraphic sleep onset time did not differ between genotypes. For PER3^4/4 carriers, self-reported sleep onset time was advanced by a larger amount and sleep onset latency (SOL) was shorter in melatonin-treated patients compared to those receiving placebo (P = .008), while actigraphic sleep efficiency in the first third of the sleep episode (SE T1) did not differ. For PER3 5 carriers, actigraphic SOL and SE T1 showed a larger improvement with melatonin (P < .001). Melatonin improved ISI (P = .005), PROMIS sleep disturbance (P < .001) and sleep-related impairment (P = .017), SDS (P = .019), PGI-C (P = .028) and CGI-C (P = .016) in PER3^4/4 individuals only. Melatonin did not advance circadian phase. Overall, PER3^4/4 DSWPD patients have a greater response to melatonin treatment. PER3 genotyping may therefore improve DSWPD patient outcomes.

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).

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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.

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

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

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

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

Chrono-Nutrition and Diet Quality in Adolescents with Delayed Sleep-Wake Phase Disorder

Background: Delayed sleep-wake phase disorder (DSPD), characterized by delayed sleep-onset and problems with awakening in the morning, is mostly prevalent in adolescents. Several studies have suggested chrono-nutrition could present a possible modifiable risk factor for DSPD. Objective: To describe differences in chrono-nutrition and diet quality in adolescents with DSPD compared to age-related controls. Methods: Chrono-nutrition and diet quality of 46 adolescents with DSPD, aged 13–20 years, and 43 controls were assessed via questionnaires. Diet quality included the Dutch Healthy Diet index (DHD-index) and Eating Choices Index (ECI). Results were analysed using logistic regression and Spearman’s partial correlation. Results: Compared with controls, DSPD patients consumed their first food of the day significantly later on weekdays (+32 ± 12 min, p = 0.010) and weekends (+25 ± 8 min, p = 0.005). They consumed their dinner more regularly (80.4% vs. 48.8%, p = 0.002) and consumed morning-snacks less frequently (3.0 ± 2.1 days vs. 4.2 ± 1.7 days, p = 0.006). No differences in clock times of breakfast, lunch, or dinner were found. Moreover, no significant differences in overall diet quality were observed. Conclusion: This descriptive study showed chrono-nutritional differences between adolescents with and without DPSD. Further studies are needed to explore features of chrono-nutrition as a possible treatment of DPSD.

Habitual Sleep, Social Jetlag, and Reaction Time in Youths With Delayed Sleep-Wake Phase Disorder. A Case-Control Study

The aim of this study was to explore habitual sleep, social jetlag, and day-to-day variations in sleep (measured as intra-individual standard deviation, ISD) in youths with delayed sleep-wake phase disorder (DSWPD), compared to healthy controls. We also aimed to investigate time of day effects in performance. The sample comprised 40 youths with DSWPD (70.0% female, mean age 20.7 ± 3.1 years) and 21 healthy controls (71.4% female, mean age 21.2 ± 2.2 years). Subjective and objective sleep were measured over 7 days on a habitual sleep schedule by sleep diary and actigraphy recordings. Performance was tested twice with a 12-h interval (22:00 in the evening and 10:00 the following morning) using a simple, 10-min sustained reaction time test (RTT). The results showed later sleep timing in the DSWPD group compared to the controls, but sleep duration, social jetlag, and ISD in sleep timing did not differ between the groups. Still, participants with DSWPD reported longer sleep onset latency (SOL) and poorer sleep efficiency (SE), sleep quality, and daytime functioning, as well as larger ISD in SOL, sleep duration, and SE. The groups had similar evening performances on the RTT, but the DSWPD group performed poorer (slower with more lapses) than the controls in the morning. The poor morning performance in the DSWPD group likely reflects the combined impact of sleep curtailment and circadian variations in performance (synchrony effect), and importantly illustrates the challenges individuals with DSWPD face when trying to adhere to early morning obligations.

The use and misuse of exogenous melatonin in the treatment of sleep disorders

PURPOSE OF REVIEW

To explore the evidence for using exogenous melatonin in the treatment of sleep disorders, both primary and secondary, in children and adults.

RECENT FINDINGS

A number of recently published meta-analyses have shown that there is evidence for the efficacy of exogenously administered melatonin in a number of sleep disorders. However, melatonin is likely to be prescribed largely for reasons of perceived minimal side-effect profile and very low cost in situations in which high-quality evidence for its usefulness is not forthcoming.

SUMMARY

There is evidence for the efficacy of melatonin in the management of insomnia and some intrinsic disorders of circadian rhythm in adults and children as well as in reducing sleep onset latency in jet-lag and shift work disorder in adults. Melatonin is used routinely in the treatment of rapid-eye movement sleep-behaviour disorder despite limited trial evidence. Increasingly, dual melatonin receptor agonists are being trialled in a variety of sleep disorders. Long-term adverse effects are currently not fully identified.

Adverse events associated with oral administration of melatonin: A critical systematic review of clinical evidence

While melatonin was once thought of simply as a sleep-inducing hormone, recent research has resulted in development of a deeper understanding of the complex physiological activity of melatonin in the human body. Along with this understanding has come widespread, increasing use of melatonin supplementation, extending beyond its traditional use as a sleep aid into novel fields of application. This increased use often involves off-label and self-prescription, escalating the importance of safety data. In order to examine the current knowledge relating to safety of the exogenous neurohormone, we conducted a comprehensive, critical systematic review of clinical evidence. We examined controlled studies of oral melatonin supplementation in humans when they presented any statistical analysis of adverse events. Of the fifty articles identified, twenty-six found no statistically significant adverse events, while twenty-four articles reported on at least one statistically significant adverse event. Adverse events were generally minor, short-lived and easily managed, with the most commonly reported adverse events relating to fatigue, mood, or psychomotor and neurocognitive performance. A few studies noted adverse events relating to endocrine (e.g. reproductive parameters, glucose metabolism) and cardiovascular (e.g. blood pressure, heart rate) function, which appear to be influenced by dosage, dose timing and potential interactions with antihypertensive drugs. Oral melatonin supplementation in humans has a generally favourable safety profile with some exceptions. Most adverse effects can likely be easily avoided or managed by dosing in accordance with natural circadian rhythms. Further research is required to explore the potential for melatonin to interact with endogenous hormones and pharmaceuticals.

Cognitive performance in DSWPD patients upon awakening from habitual sleep compared with forced conventional sleep

Difficult early morning awakening is one of the defining symptoms of delayed sleep-wake phase disorder. It is accompanied by low cognitive arousal and drowsiness resulting in difficulty concentrating and focusing attention upon awakening. We designed the current study to quantitate cognitive performance (i.e. omissions, commissions, reaction time [average and variability]) and cognitive domains (i.e. focused attention, sustained attention, impulsivity and vigilance) with Conners' Continuous Performance Test II during both habitual and conventional (00:00-07:00 hr) sleep-wake schedule in young adult patients with delayed sleep-wake phase disorder (n = 20, mean age = 24.8 years, SD = 3.0) and controls (n = 16, mean age = 24.4 years, SD = 3.4). Conners' Continuous Performance Test II was administered after awakening and in the afternoon during both habitual and conventional conditions. In-laboratory polysomnography was performed for 2 nights. We assessed sleep, tiredness, chronotype and depression using questionnaires. Saliva was sampled for dim light melatonin onset measurements. Repeated-measures ANOVAs were applied for the Conners' Continuous Performance Test II measures with group (patient/control), time (afternoon/morning) and condition (habitual/conventional schedule) as fixed factors. Patients with delayed sleep-wake phase disorder had reduced reaction times, especially in the morning, greater response speed variability, and made more omission and commission errors compared with controls. Patients with delayed sleep-wake phase disorder also had reduced focused attention, especially upon forced early awakening. The short total sleep time of patients with delayed sleep-wake phase disorder could not statistically explain this outcome. In conclusion, we observed a state-dependent reduced ability to focus attention upon early morning awakening in patients with delayed sleep-wake phase disorder. Patients also had more omissions, longer reaction time and increased RT variability after habitual sleep, suggesting a possible small cognitive trait dysfunction in delayed sleep-wake phase disorder.

Light Therapy With Scheduled Rise Times in Young Adults With Delayed Sleep Phase Disorder: Therapeutic Outcomes and Possible Predictors

Clinical trials with light therapy (LT) for delayed sleep phase disorder (DSPD) are sparse and little is known about factors that are favorable for improvements. In this study, LT with scheduled rise times was conducted at home for 14 days by 44 participants with DSPD aged 16-26 years. Primary outcomes were sleep onset and sleep offset. Potential predictors were demographic characteristics, chronotype, dim light melatonin onset, the number of days the LT lamp was used, the daily duration of LT, daytime sleepiness, anxiety, depression, worry, and rumination. Significant advances were observed in sleep onset and sleep offset from baseline to the end of treatment. The number of days of LT predicted earlier sleep onset and sleep offset.

A randomised controlled trial of bright light therapy and morning activity for adolescents and young adults with Delayed Sleep-Wake Phase Disorder

A randomised controlled trial evaluated bright light therapy and morning activity for the treatment of Delayed Sleep-Wake Phase Disorder (DSWPD) in young people. 60 adolescents and young adults (range = 13-24 years, mean = 15.9 ± 2.2 y, 63% f) diagnosed with DSWPD were randomised to receive three weeks of post-awakening Green Bright Light Therapy (∼507 nm) and Sedentary Activity (sitting, watching TV), Green Bright Light Therapy and Morning Activity (standing, playing motion-sensing videogame), Red Light Therapy (∼643 nm) and Sedentary Activity or Red Light Therapy and Morning Activity. Sleep (ie sleep onset time, wake up time, sleep onset latency, total sleep time) and daytime functioning (ie morning alertness, daytime sleepiness, fatigue, functional impairment) were measured pre-treatment, post-treatment and at one and three month follow-up. Contrary to predictions, there were no significant differences in outcomes between treatment groups; and interaction effects between treatment group and time for all outcome variables were not statistically significant. However, adolescents and young adults in morning activity conditions did not meaningfully increase their objective activity (ie movement frequency). Overall, adolescents reported significantly improved sleep timing (d = 0.30-0.46), sleep onset latency (d = 0.32) and daytime functioning (d = 0.45-0.87) post-treatment. Improvements in sleep timing (d = 0.53-0.61), sleep onset latency (d = 0.57), total sleep time (d = 0.51), and daytime functioning (d = 0.52-1.02) were maintained, or improved upon, at the three month follow-up. However, relapse of symptomology was common and 38% of adolescents and young adults requested further treatment in addition to the three weeks of light therapy. Although there is convincing evidence for the short-term efficacy of chronobiological treatments for DSWPD, long-term treatment outcomes can be improved. To address this gap in our current knowledge, avenues for future research are discussed.

CLINICAL TRIAL

Australian & New Zealand Clinical Trials Registry, https://www.anzctr.org.au, ACTRN12614000308695.

Sleep, Circadian Rhythms, and Risk Across Health Domains in Adolescents With an Evening Circadian Preference

Sleep and circadian rhythm changes during adolescence contribute to increased risk across emotional, behavioral, cognitive, social, and physical health domains. This study examines if sleep and dim light melatonin onset (DLMO) are related to greater risk in these 5 health domains. Participants were 163 (93 female, age = 14.7 years) adolescents with an evening circadian preference from a study funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Sleep and circadian measures included weekday total sleep time (TST), bedtime, and shut-eye time assessed via sleep diary, the Children's Morningness-Eveningness Preferences scale, and DLMO. Health domains included self-reported emotional, cognitive, behavioral, social, and physical health. Later DLMO was significantly associated with shorter weekday TST, later weekday bedtime, and later weekday shut-eye time, as well as lower risk in the behavioral domain. At the trend level, later DLMO was related to fewer physical health problems. Earlier DLMO combined with a later bedtime, later shut-eye time, or shorter TST predicted greater risk in the cognitive domain. Later DLMO and shorter TST or a later bedtime predicted worse physical health. DLMO timing was not related to the emotional or social domain. There is evidence that a discrepancy between sleep behaviors and the endogenous circadian rhythm may be related to risk in the cognitive domain for adolescents with an evening circadian preference. Preliminary evidence also indicated that a delayed DLMO and shorter TST or a later bedtime may be related to vulnerability to physical health risk.

Depressive disorders: Processes leading to neurogeneration and potential novel treatments

Mood disorders are wide spread with estimates that one in seven of the population are affected at some time in their life (Kessler et al., 2012). Many of those affected with severe depressive disorders have cognitive deficits which may progress to frank neurodegeneration. There are several peripheral markers shown by patients who have cognitive deficits that could represent causative factors and could potentially serve as guides to the prevention or even treatment of neurodegeneration. Circadian rhythm misalignment, immune dysfunction and oxidative stress are key pathologic processes implicated in neurodegeneration and cognitive dysfunction in depressive disorders. Novel treatments targeting these pathways may therefore potentially improve patient outcomes whereby the primary mechanism of action is outside of the monoaminergic system. Moreover, targeting immune dysfunction, oxidative stress and circadian rhythm misalignment (rather than primarily the monoaminergic system) may hold promise for truly disease modifying treatments that may prevent neurodegeneration rather than simply alleviating symptoms with no curative intent. Further research is required to more comprehensively understand the contributions of these pathways to the pathophysiology of depressive disorders to allow for disease modifying treatments to be discovered.

Correcting delayed circadian phase with bright light therapy predicts improvement in ADHD symptoms: A pilot study

Attention-deficit/hyperactivity disorder (ADHD) is a common condition with comorbid insomnia reported in >70% of children and adults. These patients demonstrate delays in sleep-wake rhythms, nocturnal rise in melatonin, and early morning rise in cortisol. Given that standard psychopharmacologic treatments for ADHD often do not completely control symptoms in participants with circadian rhythm delay, we sought to test whether bright light therapy (BLT) advances circadian rhythms and further reduces ADHD symptoms over standard treatments. In addition to standard of care, participants with ADHD diagnosis underwent 1 week of baseline assessment followed by 2-weeks of 30-min morning 10,000-lux BLT beginning 3 h after mid-sleep time. Participants minimized overhead light after 4 p.m., wore an actigraphy watch, and recorded BLT time on daily sleep logs. Dim Light Melatonin Onset (DLMO) was assessed at baseline and after 2-week treatment. ADHD symptoms were measured by the ADHD-Rating Scales (ADHD-RS). BLT significantly advanced the phase of DLMO by 31 min [mean time (SEM), 20:36 (0:21) advanced to 20:05 (0:20)] and mid-sleep time by 57 min [4:37 (0:22) advanced to 3:40 (0:16); paired t-tests, p = 0.002 and 0.004, respectively). Phase advances (in DLMO or mid-sleep time) were significantly correlated with decreased ADHD-RS total scores (p = 0.027 and 0.044) and Hyperactive-Impulsive sub-scores (p = 0.014 and 0.013, respectively). Actigraphy analysis for a subset of 8 participants with significant DLMO phase advance revealed no significant changes in total sleep time, sleep efficiency, wake after sleep onset, or percent wake during sleep interval. This is the first successful use of BLT for advancing melatonin phase and improving ADHD symptoms in adults. BLT may be a complementary treatment for both delayed sleep timing and ADHD symptoms in adults.

How Many Sleep Diary Entries Are Needed to Reliably Estimate Adolescent Sleep?

Study Objectives

To investigate (1) how many nights of sleep diary entries are required for reliable estimates of five sleep-related outcomes (bedtime, wake time, sleep onset latency [SOL], sleep duration, and wake after sleep onset [WASO]) and (2) the test-retest reliability of sleep diary estimates of school night sleep across 12 weeks.

Methods

Data were drawn from four adolescent samples (Australia [n = 385], Qatar [n = 245], United Kingdom [n = 770], and United States [n = 366]), who provided 1766 eligible sleep diary weeks for reliability analyses. We performed reliability analyses for each cohort using complete data (7 days), one to five school nights, and one to two weekend nights. We also performed test-retest reliability analyses on 12-week sleep diary data available from a subgroup of 55 US adolescents.

Results

Intraclass correlation coefficients for bedtime, SOL, and sleep duration indicated good-to-excellent reliability from five weekday nights of sleep diary entries across all adolescent cohorts. Four school nights was sufficient for wake times in the Australian and UK samples, but not the US or Qatari samples. Only Australian adolescents showed good reliability for two weekend nights of bedtime reports; estimates of SOL were adequate for UK adolescents based on two weekend nights. WASO was not reliably estimated using 1 week of sleep diaries. We observed excellent test-rest reliability across 12 weeks of sleep diary data in a subsample of US adolescents.

Conclusion

We recommend at least five weekday nights of sleep dairy entries to be made when studying adolescent bedtimes, SOL, and sleep duration. Adolescent sleep patterns were stable across 12 consecutive school weeks.

Can the circadian phase be estimated from self-reported sleep timing in patients with Delayed Sleep Wake Phase Disorder to guide timing of chronobiologic treatment?

INTRODUCTION

The efficacy of bright light and/or melatonin treatment for Delayed Sleep Wake Phase Disorder (DSWPD) is contingent upon an accurate clinical assessment of the circadian phase. However, the process of determining this circadian phase can be costly and is not yet readily available in the clinical setting. The present study investigated whether more cost-effective and convenient estimates of the circadian phase, such as self-reported sleep timing, can be used to predict the circadian phase and guide the timing of light and/or melatonin treatment (i.e. dim-light melatonin onset, core body temperature minimum and melatonin secretion mid-point) in a sample of individuals with DSWPD.

METHOD

Twenty-four individuals (male = 17; mean age = 21.96, SD = 5.11) with DSWPD were selected on the basis of ICSD-3 criteria from a community-based sample. The first 24-hours of a longer 80-hour constant laboratory ultradian routine were used to determine core body temperature minimum (cBT^min), dim-light melatonin onset (DLMO) and the midpoint of the melatonin secretion period (DLM^mid = [DLM°^ff-DLMO]/2). Prior to the laboratory session subjective sleep timing was assessed using a 7-day sleep/wake diary, the Pittsburgh Sleep Quality Index (PSQI), and the Delayed Sleep Phase Disorder Sleep Timing Questionnaire (DSPD-STQ).

RESULTS

Significant moderate to strong positive correlations were observed between self-reported sleep timing variables and DLMO, cBT^min and DLM^mid. Regression equations revealed that the circadian phase (DLMO, cBT^min and DLM^mid) was estimated within ±1.5 hours of the measured circadian phase most accurately by the combination of sleep timing measures (88% of the sample) followed by sleep diary reported midsleep (83% of the sample) and sleep onset time (79% of the sample).

DISCUSSION

These findings suggest that self-reported sleep timing may be useful clinically to predict a therapeutically relevant circadian phase in DSWPD.

Developing a cognitive behavioral therapy manual for delayed sleep-wake phase disorder

This article reports the development of a treatment protocol, based on cognitive behavioral therapy (CBT) principles, for delayed sleep-wake phase disorder (DSWPD). The protocol consists of psycho-education, presenting a CBT model for DSWPD, case formulation, motivational interviewing, registering sleep in a diary, strategies to improve the rhythm of sleep and wakefulness, relaxation training, cognitive restructuring, strategies to cope with daytime symptoms, constructing an individualized CBT program, and learning how to deal with relapses. Qualitative data, focusing on how the patients perceived the protocol, were collected within the realm of a trial exploring the efficacy of the protocol. These findings highlighted several advantages but also disadvantages of the therapy. It is our hope that this paper might act as a platform for further clinical work and future research efforts in patients with DSWPD.

Evidence for the efficacy of melatonin in the treatment of primary adult sleep disorders

Melatonin is a physiological hormone involved in sleep timing and is currently used exogenously in the treatment of primary and secondary sleep disorders with empirical evidence of efficacy, but very little evidence from randomised, controlled studies. The aim of this meta-analysis was to assess the evidence base for the therapeutic effects of exogenous melatonin in treating primary sleep disorders. An electronic literature review search of MEDLINE (1950-present) Embase (1980- present), PsycINFO (1987- present), and Scopus (1990- present), along with a hand-searching of key journals was performed in July 2013 and then again in May 2015. This identified all studies that compared the effect of exogenous melatonin and placebo in patients with primary insomnia, delayed sleep phase syndrome, non 24-h sleep wake syndrome in people who are blind, and rapid eye movement-behaviour disorder. Meta-analyses were performed to determine the magnitude of effect in studies of melatonin in improving sleep. A total of 5030 studies were identified; of these citations, 12 were included for review based on the inclusion criteria of being: double or single-blind, randomised and controlled. Results from the meta-analyses showed the most convincing evidence for exogenous melatonin use was in reducing sleep onset latency in primary insomnia (p = 0.002), delayed sleep phase syndrome (p < 0.0001), and regulating the sleep-wake patterns in blind patients compared with placebo. These findings highlight the potential importance of melatonin in treating certain first degree sleep disorders. The development of large-scale, randomised, controlled trials is recommended to provide further evidence for therapeutic use of melatonin in a variety of sleep difficulties.

The effect of lens aging and cataract surgery on circadian rhythm

Many organisms have evolved an approximately 24-hour circadian rhythm that allows them to achieve internal physiological homeostasis with external environment. Suprachiasmatic nucleus (SCN) is the central pacemaker of circadian rhythm, and its activity is entrained to the external light-dark cycle. The SCN controls circadian rhythm through regulating the synthesis of melatonin by pineal gland via a multisynaptic pathway. Light, especially short-wavelength blue light, is the most potent environmental time cue in circadian photoentrainment. Recently, the discovery of a novel type of retinal photoreceptors, intrinsically photosensitive retinal ganglion cells, sheds light on the mechanism of circadian photoentrainment and raises concerns about the effect of ocular diseases on circadian system. With age, light transmittance is significantly decreased due to the aging of crystalline lens, thus possibly resulting in progressive loss of circadian photoreception. In the current review, we summarize the circadian physiology, highlight the important role of light in circadian rhythm regulation, discuss about the correlation between age-related cataract and sleep disorders, and compare the effect of blue light- filtering intraocular lenses (IOLs) and ultraviolet only filtering IOLs on circadian rhythm.

Diagnosis, Cause, and Treatment Approaches for Delayed Sleep-Wake Phase Disorder

Delayed sleep-wake phase disorder (DSWPD) is commonly defined as an inability to fall asleep and wake at societal times resulting in excessive daytime sleepiness. Although the cause is multifaceted, delays in sleep time are largely driven by misalignment between the circadian pacemaker and the desired sleep-wake timing schedule. Current treatment approaches focus on correcting the circadian delay; however, there is a lack of data investigating combined therapies for treatment of DSWPD.

Cognitive Behavioral Therapy as an Adjunct Treatment to Light Therapy for Delayed Sleep Phase Disorder in Young Adults: A Randomized Controlled Feasibility Study

Delayed sleep phase disorder (DSPD) is common among young people, but there is still no evidence-based treatment available. In the present study, the feasibility of cognitive behavioral therapy (CBT) was evaluated as an additive treatment to light therapy (LT) in DSPD. A randomized controlled trial with participants aged 16 to 26 years received LT for two weeks followed by either four weeks of CBT or no treatment (NT). LT advanced sleep-wake rhythm in both groups. Comparing LT+CBT with LT+NT, no significant group differences were observed in the primary endpoints. Although anxiety and depression scores were low at pretreatment, they decreased significantly more in LT+CBT compared to LT+NT. The results are discussed and some suggestions are given for further studies.

Circadian Melatonin and Temperature Taus in Delayed Sleep-wake Phase Disorder and Non-24-hour Sleep-wake Rhythm Disorder Patients: An Ultradian Constant Routine Study

Our objectives were to investigate the period lengths (i.e., taus) of the endogenous core body temperature rhythm and melatonin rhythm in delayed sleep-wake phase disorder patients (DSWPD) and non-24-h sleep-wake rhythm disorder patients (N24SWD) compared with normally entrained individuals. Circadian rhythms were measured during an 80-h ultradian modified constant routine consisting of 80 ultrashort 1-h "days" in which participants had 20-min sleep opportunities alternating with 40 min of enforced wakefulness. We recruited a community-based sample of 26 DSWPD patients who met diagnostic criteria (17 males, 9 females; age, 21.85 ± 4.97 years) and 18 healthy controls (10 males, 8 females; age, 23.72 ± 5.10 years). Additionally, 4 full-sighted patients (3 males, 1 female; age, 25.75 ± 4.99 years) were diagnosed with N24SWD and included as a discrete study group. Ingestible core temperature capsules were used to record minute temperatures that were averaged to obtain 80 hourly data points. Salivary melatonin concentration was assessed every half-hour to determine time of dim light melatonin onset at the beginning and end of the 80-h protocol. DSWPD patients had significantly longer melatonin rhythm taus (24 h 34 min ± 17 min) than controls (24 h 22 min ± 15 min, p = 0.03, d = 0.70). These results were further supported by longer temperature rhythm taus in DSWPD patients (24 h 34 min ± 26 min) relative to controls (24 h 13 min ± 15 min, p = 0.01, d = 0.80). N24SWD patients had even longer melatonin (25 h ± 19 min) and temperature (24 h 52 min ± 17 min) taus than both DSWPD (p = 0.007, p = 0.06) and control participants (p < 0.001, p = 0.02, respectively). Between 12% and 19% of the variance in DSWPD patients' sleep timing could be explained by longer taus. This indicates that longer taus of circadian rhythms may contribute to the DSWPD patients' persistent tendency to delay, their frequent failure to respond to treatment, and their relapse following treatment. Additionally, other factors can contribute to misalignments in DSWPD and N24SWD disorders.

Quinpirole Increases Melatonin-Augmented Pentobarbital Sleep via Cortical ERK, p38 MAPK, and PKC in Mice

Sleep, which is an essential part of human life, is modulated by neurotransmitter systems, including gamma-aminobutyric acid (GABA) and dopamine signaling. However, the mechanisms that initiate and maintain sleep remain obscure. In this study, we investigated the relationship between melatonin (MT) and dopamine D2-like receptor signaling in pentobarbital-induced sleep and the intracellular mechanisms of sleep maintenance in the cerebral cortex. In mice, pentobarbital-induced sleep was augmented by intraperitoneal administration of 30 mg/kg MT. To investigate the relationship between MT and D2-like receptors, we administered quinpirole, a D2-like receptor agonist, to MT- and pentobarbital-treated mice. Quinpirole (1 mg/kg, i.p.) increased the duration of MT-augmented sleep in mice. In addition, locomotor activity analysis showed that neither MT nor quinpirole produced sedative effects when administered alone. In order to understand the mechanisms underlying quinpirole-augmented sleep, we measured protein levels of mitogen-activated protein kinases (MAPKs) and cortical protein kinases related to MT signaling. Treatment with quinpirole or MT activated extracellular-signal-regulated kinase 1 and 2 (ERK1/2), p38 MAPK, and protein kinase C (PKC) in the cerebral cortex, while protein kinase A (PKA) activation was not altered significantl. Taken together, our results show that quinpirole increases the duration of MT-augmented sleep through ERK1/2, p38 MAPK, and PKC signaling. These findingssuggest that modulation of D2-like receptors might enhance the effect of MT on sleep.

Circadian Rhythm Sleep-Wake Disorders

The circadian system regulates the timing and expression of nearly all biological processes, most notably, the sleep-wake cycle, and disruption of this system can result in adverse effects on both physical and mental health. The circadian rhythm sleep-wake disorders (CRSWDs) consist of 5 disorders that are due primarily to pathology of the circadian clock or to a misalignment of the timing of the endogenous circadian rhythm with the environment. This article outlines the nature of these disorders, the association of many of these disorders with psychiatric illness, and available treatment options.

The effects of light therapy on sleep problems: A systematic review and meta-analysis

Although bright light therapy seems a promising treatment for sleep problems, research shows inconclusive results. This meta-analysis is the first to systematically review the effect of light therapy on sleep problems in general and on specific types of sleep problems in particular (circadian rhythm sleep disorders, insomnia, sleep problems related to Alzheimer's disease and dementia). Fifty-three studies with a total of 1154 participants were included. Overall effects and effects on separate circadian and sleep outcomes were examined. We calculated Hedges' g effect sizes and we investigated the effects of twelve moderators (design-related, treatment-related, participant-related). Light therapy was found effective in the treatment of sleep problems in general (g = 0.39), and for circadian rhythm sleep disorders (g = 0.41), insomnia (g = 0.47), and sleep problems related to Alzheimer's disease/dementia (g = 0.30) specifically. For circadian rhythm sleep disorders, effects were smaller for randomised controlled trials. For insomnia, we found larger effects for studies using a higher light intensity, and for sleep problems related to Alzheimer's disease/dementia larger effects were found for studies with more female participants. There was indication of publication bias. To conclude, light therapy is effective for sleep problems in general, particularly for circadian outcomes and insomnia symptoms. However, most effect sizes are small to medium.

Melatonin Regulates Oxidative Stress Initiated by Freund’s Complete Adjuvant

Melatonin is a hormone with strong antioxidant properties. In this experiment, Freund’s complete adjuvant was used as a stressogenic substance given to laboratory outbred mice, whereas melatonin was investigated as a protectant against the stressogenic effect. Levels of low molecular weight antioxidants, thiobarbituric acid reactive substances, and tumor necrosis factor α and activity of glutathione reductase were determined in blood from the animals. Surprisingly, melatonin was not involved in direct regulation of antioxidants, thiobarbituric acid reactive substances and tumor necrosis factor α. On the other hand, melatonin regulated glutathione reductase activity. We can conclude on regulation of metabolism caused by melatonin in the model. The effect was more important than the expected regulation of immunity and basal oxidative homeostasis.

The etiology of delayed sleep phase disorder

According to classification manuals for sleep disorders, nine disorders are directly related to biological clock timing misalignments. Of all, delayed sleep phase disorder (DSPD) is the most commonly diagnosed, predominantly affecting adolescents, young adults, and insomnia patients. It is a persistent inability to fall asleep at earlier, more desirable and socially conventional times, coupled with extreme difficulty awakening in the morning. Considerable evidence shows a delay in the circadian clock to be associated with DSPD. Therefore, treatments have mainly focused on advancing the biological clock and sleep timing through pharmacotherapy, phototherapy and behavioral therapies. The clinical evidence indicates that these treatments are efficacious, at least in the short term. However, follow up studies show frequent patient relapse, leading researchers to speculate that alternative etiologies may be contributing to sleep and circadian clock delays in DSPD. The aim of the present paper is to review and collate current literature related to DSPD etiology in order to outline gaps in current knowledge and suggest future research.

Are cognitive "insomnia" processes involved in the development and maintenance of delayed sleep wake phase disorder?

Although individuals with delayed sleep wake phase disorder (DSWPD) and chronic insomnia disorder (CID) share many of the same phenomenological experiences, theories relating to the development and maintenance of these disorders are distinct in focus. Unlike CID, theory relating to DSWPD is primarily physiologically based and assumes almost no cognitive pathway. However, recent research findings suggest that individuals with DSWPD also display many of the sleep-disordered cognitive processes that were previously assumed to be unique to the insomnia experience. As such, this review aims to summarise current research findings to address the question "Could cognitive processes be involved in the development and maintenance of DSWPD?" In particular, the presence of cognitive and physiological pre-sleep arousal, sleep-related attentional bias, distorted perception of sleep and daytime functioning, dysfunctional beliefs and safety behaviours will be investigated. As this emerging area of research requires a stronger evidence base, we highlight suggestions for future investigation and provide preliminary practice points for clinicians assessing and treating "insomnia" in patients with DSWPD.

Current role of melatonin in pediatric neurology: clinical recommendations

BACKGROUND/PURPOSE

Melatonin, an indoleamine secreted by the pineal gland, plays a key role in regulating circadian rhythm. It has chronobiotic, antioxidant, anti-inflammatory and free radical scavenging properties.

METHODS

A conference in Rome in 2014 aimed to establish consensus on the roles of melatonin in children and on treatment guidelines.

RESULTS AND CONCLUSION

The best evidence for efficacy is in sleep onset insomnia and delayed sleep phase syndrome. It is most effective when administered 3-5 h before physiological dim light melatonin onset. There is no evidence that extended-release melatonin confers advantage over immediate release. Many children with developmental disorders, such as autism spectrum disorder, attention-deficit/hyperactivity disorder and intellectual disability have sleep disturbance and can benefit from melatonin treatment. Melatonin decreases sleep onset latency and increases total sleep time but does not decrease night awakenings. Decreased CYP 1A2 activity, genetically determined or from concomitant medication, can slow metabolism, with loss of variation in melatonin level and loss of effect. Decreasing the dose can remedy this. Animal work and limited human data suggest that melatonin does not exacerbate seizures and might decrease them. Melatonin has been used successfully in treating headache. Animal work has confirmed a neuroprotective effect of melatonin, suggesting a role in minimising neuronal damage from birth asphyxia; results from human studies are awaited. Melatonin can also be of value in the performance of sleep EEGs and as sedation for brainstem auditory evoked potential assessments. No serious adverse effects of melatonin in humans have been identified.