Idiopathic Chronic Sleep Onset Insomnia in Attention‐Deficit/Hyperactivity Disorder: A Circadian Rhythm Sleep Disorder

Sleep insufficiency and bedtime irregularity in children with ADHD: A population-based analysis

BACKGROUND

Sleep is impaired in children with attention-deficit/hyperactivity disorder (ADHD). However, population-based examination of indicators of sleep insufficiency and bedtime irregularity is limited. This investigation examined associations between ADHD, weeknight sleep insufficiency, and bedtime irregularity in a nationally-representative child sample, and indicators of these sleep outcomes in ADHD.

METHODS

Parents of children aged 3-17 years with ADHD (n = 7671) were surveyed through the 2020-2021 National Survey of Children's Health. Inverse probability of treatment weighting generated a weighted matched control sample (n = 51,572). Weighted generalized linear models were performed without and with age-stratification to examine associations between ADHD and sleep, adjusting for sociodemographics in the full sample, and between nineteen sociodemographic and clinical variables and sleep in ADHD.

RESULTS

Having ADHD was associated with increased odds of sleep insufficiency and bedtime irregularity relative to controls, even after adjusting for sociodemographic variables. In ADHD, older age was associated with lower sleep insufficiency and greater bedtime irregularity. Black race, increased poverty, higher ADHD severity, depression, and increased screen time were associated with greater sleep insufficiency and bedtime irregularity. Adverse childhood experiences (ACEs) were associated with greater sleep insufficiency. Behavioral/conduct problems, female sex, and absence of both ADHD medication use and ASD diagnosis were associated with poorer bedtime irregularity. Age-stratified results are reported in text.

CONCLUSIONS

Children with ADHD face heightened risk for insufficient sleep and irregular bedtimes. Findings suggest intervention targets (e.g., Black race, poverty, depression, screen time) to improve both sleep insufficiency and bedtime irregularity. Results highlight ACEs and behavioral/conduct problems as targets to improve sleep insufficiency and bedtime regularity, respectively. Age-stratified findings are discussed.

Sleep problems and circadian rhythm functioning in autistic children, autism with co-occurring attention deficit hyperactivity disorder, and typically developing children: A comparative study

LAY ABSTRACT

Sleep problems are common in autism spectrum disorder (ASD) and different factors can contribute to its occurrence in this population. Misalignment of the biological clock (our circadian system) has been described as one possible explanation. While there is a body of research on sleep problems, relatively less is known about circadian functioning and the specific population of autistic children with co-occurring attention deficit hyperactivity disorder (ADHD). Using an ambulatory circadian monitoring (ACM) system, which resembles a common watch, we gathered sleep parameters and the different rhythms obtained from measuring motor activity, light exposure and distal temperature in 87 autistic children and adolescents, 27 of whom were diagnosed with co-occurring ADHD, and 30 neurotypical children and adolescents as a comparison group. Autistic children and, especially, those with co-occurring ADHD showed greater motor activity during sleep which would be worth studying in future projects which could better define this restless sleep. Of note, we observed an atypical pattern of wrist temperature, with higher values in neurotypical children, followed by autistic children and, ultimately, those with co-occurring ADHD. Temperature is one of the most valuable factors evaluated here as it is closely connected to sleep-wakefulness and the hormone melatonin. Its special pattern during day and nighttime would support the hypothesis of an atypical secretion of melatonin in autistic individuals which would also link with the higher presence of sleep problems in this neurodevelopmental condition.

Developmental pyrethroid exposure disrupts molecular pathways for MAP kinase and circadian rhythms in mouse brain

Neurodevelopmental disorders (NDDs) are a category of pervasive disorders of the developing nervous system with few or no recognized biomarkers. A significant portion of the risk for NDDs, including attention deficit hyperactivity disorder (ADHD), is contributed by the environment, and exposure to pyrethroid pesticides during pregnancy has been identified as a potential risk factor for NDD in the unborn child. We recently showed that low-dose developmental exposure to the pyrethroid pesticide deltamethrin in mice causes male-biased changes to ADHD- and NDD-relevant behaviors as well as the striatal dopamine system. Here, we used an integrated multiomics approach to determine the broadest possible set of biological changes in the mouse brain caused by developmental pyrethroid exposure (DPE). Using a litter-based, split-sample design, we exposed mouse dams during pregnancy and lactation to deltamethrin (3 mg/kg or vehicle every 3 days) at a concentration well below the EPA-determined benchmark dose used for regulatory guidance. We raised male offspring to adulthood, euthanized them, and pulverized and divided whole brain samples for split-sample transcriptomics, kinomics and multiomics integration. Transcriptome analysis revealed alterations to multiple canonical clock genes, and kinome analysis revealed changes in the activity of multiple kinases involved in synaptic plasticity, including the mitogen-activated protein (MAP) kinase ERK. Multiomics integration revealed a dysregulated protein-protein interaction network containing primary clusters for MAP kinase cascades, regulation of apoptosis, and synaptic function. These results demonstrate that DPE causes a multi-modal biophenotype in the brain relevant to ADHD and identifies new potential mechanisms of action.

NEW & NOTEWORTHY

Here, we provide the first evidence that low-dose developmental exposure to the pyrethroid pesticide, deltamethrin, results in molecular disruptions in the adult mouse brain in pathways regulating circadian rhythms and neuronal growth (MAP kinase). This same exposure causes a neurodevelopmental disorder (NDD) relevant behavioral changes in adult mice, making these findings relevant to the prevention of NDDs.

Circadian aspects in the aetiology and pathophysiology of insomnia

Because the endogenous circadian pacemaker is a very strong determinant of alertness/sleep propensity across the 24 h period, its mistiming may contribute to symptoms of insomnia (e.g., difficulties initiating sleep and maintaining sleep) and to the development of insomnia disorder. Despite the separation of insomnia and circadian rhythm disorders in diagnostic nosology implying independent pathophysiology, there is considerable evidence of co-morbidity and interaction between them. Sleep onset insomnia is associated with later timed circadian rhythms and can be treated with morning bright light to shift rhythms to an earlier timing. It is also possible that the causal link may go in both directions and that having a delayed circadian rhythm can result in enough experiences of delayed sleep onset to lead to some conditioned insomnia or insomnia disorder further exacerbating a delayed circadian rhythm. Early morning awakening insomnia is associated with an advanced circadian phase (early timing) and can be treated with evening bright light resulting in a delay of rhythms and an improved ability to sleep later in the morning and to obtain more sleep. There is some evidence suggesting that sleep maintenance insomnia is associated with a blunted amplitude of circadian rhythm that may be treated with increased regularity of sleep and light exposure timing. However, this is an insomnia phenotype that requires considerably more circadian research as well as further insomnia clinical research with the other insomnia phenotypes incorporating circadian timing measures and treatments.

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.

Low Doses of Melatonin to Improve Sleep in Children with ADHD: An Open-Label Trial

OBJECTIVE

Only a few studies assessing the sleep effects of low doses of melatonin (aMT) have been performed in the past, most of them in adults, and only one in subjects with attention-deficit/hyperactivity disorder (ADHD). The aim of this study was to provide evidence of the changes induced by aMT doses as low as 1 mg in the sleep pattern of pediatric patients with ADHD under treatment with methylphenidate (MPH).

METHODS

Children and adolescents (7-15 years) with ADHD who were receiving extended-release MPH were recruited. A seven-week sleep diary was collected prior to starting a four-week treatment with 1 mg of aMT (30 min before bedtime). Seven-day actigraphic assessments of sleep were performed before and after treatment.

RESULTS

Twenty-seven patients (17 males, 62.96%) participated in the study, who had been receiving MPH for 1.57 (1.11) months. A significant increase in sleep duration (TST) was observed after one month of treatment (463 (49) min to 485 (41) min; p < 0.040), with nonsignificant improvements in sleep-onset latency (SOL), nocturnal awakenings, or sleep efficiency. Only minor adverse effects were reported.

CONCLUSION

Low doses of melatonin (1 mg) are able to increase TST in children and adolescents with ADHD receiving treatment with psychostimulants, with an adequate tolerability profile. Further placebo-controlled trials adjusting the time of aMT administration to the individual circadian profile should explore the effects of low doses of this hormone to shorten SOL in this population of patients.

Characterizing rest-activity rhythms and sleep for children with and without tactile sensitivities: An observational study

STUDY OBJECTIVES

This cross-sectional, observational study aimed to characterize and compare movement-based rest-activity rhythms (RARs) and sleep period variables of children with tactile hypersensitivities (SS) and non-sensitive peers (NSS) to expand the understanding of experienced differences in sleep.

METHODS

Children (ages 6-10) wore Actigraph GT9X watches for 2 weeks and caregivers completed daily sleep diaries. RARs and sleep period variables (e.g., sleep efficiency, duration, wake after sleep onset) were analyzed and localized means were plotted to visualize average rhythms for each group. Groups were compared using Student's t tests, or non-parametric alternatives, and Hedge's g effect sizes.

RESULTS

Fifty-three children and their families participated in this study (nSS = 21 nNSS = 32). The groups had similar RARs and sleep period variables. In both groups, sleep efficiency was low (SESS = 78%, SENSS = 77%) and total sleep time was short (TSTSS = 7 hrs 26 mins, TSTNSS- 7 h, 33 min) compared to national recommendations. Despite these similarities, children with SS took noticeably longer to settle down and fall asleep (53 min) than children with NSS (26 min, p = .075, g = 0.95).

CONCLUSION

This study provides preliminary data describing RAR and sleep period variables in children with and without tactile hypersensitivities. While overall RAR and sleep variables were similar between groups, there is evidence that children with SS spend a longer time transitioning to sleep. Evidence is provided that wrist-worn actigraphy is tolerable and acceptable for children with tactile sensitivities. Actigraphy provides important, movement-based data that should be used in tandem with other measures of sleep health for future studies.

Sleep Structure in Untreated Adults With ADHD: A Retrospective Study

OBJECTIVE

Polysomnographic findings in neurodevelopmental disorders have been reported, but previous studies have had several limitations. The purpose of this study was to characterize sleep structure in untreated adults diagnosed with ADHD, excluding ADHD-related sleep disorders as determined by polysomnography and multiple sleep latency testing.

METHODS

This study included 55 patients aged 18 years or older who visited the Kurume University Hospital Sleep Clinic between April 2015 and March 2020. The diagnosis of ADHD was determined by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (ADHD group, n = 28; non-ADHD, n = 27).

RESULTS

The ADHD group had significantly longer slow wave sleep (SWS) duration than the non-ADHD group (ADHD: 68.3 ± 31.0 minutes vs. non-ADHD: 43.4 ± 36.6 minutes; p = .0127).

CONCLUSIONS

The increased SWS volume observed in drug-naïve adult patients with ADHD may be related to the pathogenesis of this disorder.

Actigraphy in studies on insomnia: Worth the effort?

In the past decades, actigraphy has emerged as a promising, cost-effective, and easy-to-use tool for ambulatory sleep recording. Polysomnography (PSG) validation studies showed that actigraphic sleep estimates fare relatively well in healthy sleepers. Additionally, round-the-clock actigraphy recording has been used to study circadian rhythms in various populations. To this date, however, there is little evidence that the diagnosis, monitoring, or treatment of insomnia can significantly benefit from actigraphy recordings. Using a case-control design, we therefore critically examined whether mean or within-subject variability of actigraphy sleep estimates or circadian patterns add to the understanding of sleep complaints in insomnia. We acquired actigraphy recordings and sleep diaries of 37 controls and 167 patients with varying degrees of insomnia severity for up to 9 consecutive days in their home environment. Additionally, the participants spent one night in the laboratory, where actigraphy was recorded alongside PSG to check whether sleep, in principle, is well estimated. Despite moderate to strong agreement between actigraphy and PSG sleep scoring in the laboratory, ambulatory actigraphic estimates of average sleep and circadian rhythm variables failed to successfully differentiate patients with insomnia from controls in the home environment. Only total sleep time differed between the groups. Additionally, within-subject variability of sleep efficiency and wake after sleep onset was higher in patients. Insomnia research may therefore benefit from shifting attention from average sleep variables to day-to-day variability or from the development of non-motor home-assessed indicators of sleep quality.

Sleep Disturbances in Adolescents with Attention-Deficit/Hyperactivity Disorder

Introduction

Delayed sleep phase syndrome (DSPS) and insomnia disorders are prevalent in adolescents and are comorbid with attention-deficit/hyperactivity disorder (ADHD), but only limited information is available regarding the prevalence of DSPS and insomnia in adolescents with ADHD. Moreover, previous studies comparing objective sleep parameters averaged the findings across all participants of each group (ADHD, control) regardless of each individual's level of reported sleep disturbance. This might have resulted in inconsistency between information obtained by objective and subjective sleep measures in adolescents with ADHD. The objectives of the present study were 1) to compare the prevalence of risk for DSPS and insomnia in adolescents with ADHD and control adolescents in our samples; 2) to compare objectively measured sleep characteristics of adolescents with ADHD and controls while taking into consideration their levels of risk for DSPS or their level of insomnia; and 3) to compare the ADHD symptom levels of adolescents with moderate/high and low risk for DSPS or insomnia.

Methods

Seventy-three adolescents (37 ADHD, 36 controls) aged 12-15 years participated in a cross-sectional study. Actigraphy was used to characterize objective sleep parameters and parents' or adolescents' reports were used to characterize subjective sleep parameters.

Results

Of the participants in the ADHD and control groups, 33.33% and 27%, respectively, had moderate/high levels of risk for DSPS. Adolescents in the high-risk group for DSPS had an objectively measured delayed sleep schedule and more variable sleep duration, time in bed, and sleep efficiency compared to adolescents in the low-risk group for DSPS, regardless of their ADHD diagnosis. Adolescents with higher levels of insomnia spent more time in bed and had more variable sleep efficiency compared to adolescents with no insomnia, regardless of their diagnosis.

Conclusion

The prevalence of moderate/high risk for DSPS was similarly high in adolescents with ADHD and controls. Participants' subjective reports of sleep disturbances were consistent with their objective sleep parameters when the type and level of subjectively defined sleep disturbance were considered. ADHD symptom levels were not different in adolescents with moderate/high or low risk for DSPS or insomnia.

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.

Clock Genes Profiles as Diagnostic Tool in (Childhood) ADHD—A Pilot Study

Attention deficit hyperactivity disorder (ADHD) is a very common disorder in children and adults. A connection with sleep disorders, and above all, disorders of the circadian rhythm are the subject of research and debate. The circadian system can be represented on different levels. There have been a variety of studies examining 24-h rhythms at the behavioral and endocrine level. At the molecular level, these rhythms are based on a series of feedback loops of core clock genes and proteins. In this paper, we compared the circadian rhythms at the behavioral, endocrine, and molecular levels between children with ADHD and age- and BMI-matched controls, complementing the previous data in adults. In a minimally invasive setting, sleep was assessed via a questionnaire, actigraphy was used to determine the motor activity and light exposure, saliva samples were taken to assess the 24-h profiles of cortisol and melatonin, and buccal mucosa swaps were taken to assess the expression of the clock genes BMAL1 and PER2. We found significant group differences in sleep onset and sleep duration, cortisol secretion profiles, and in the expression of both clock genes. Our data suggest that the analysis of circadian molecular rhythms may provide a new approach for diagnosing ADHD in children and adults.

A Cross-Sectional Comparative Study of Sleep Disturbances in Children with ADHD and Matched Controls

Background: Systematic reviews conducted on sleep disturbances in attention deficit hyperactivity disorder (ADHD) have found inconsistent results due to the presence of several moderating variables which were not controlled for in previous studies. The aim of this study was to examine sleep disturbances in children with ADHD compared to their typically developing peers after controlling for moderating variables (age, sex, medication status, body mass index, and psychiatric and medical comorbidities). Methods: ADHD was diagnosed using DSM-IV-TR criteria (Diagnostic and Statistical Manual of Mental Disorders) and Conners’ Parent Rating Scales. Children recruited (aged 6−12 years) for the ADHD group (n = 40) met the following criteria: IQ > 80, unmedicated, and no psychiatric or medical comorbidities. The control group consisted of age- and sex-matched typically developing peers (n = 40). Sleep was assessed subjectively (through parent reported questionnaires and sleep logs) and objectively (using video polysomnography). Results: 65% of children with ADHD had a sleep disorder, as compared to 17% of controls. The ADHD group reported more sleep disturbances and disorders, both on subjective measures and objective measures. Conclusions: Sleep disturbances and primary sleep disorders in children with ADHD exist independent of moderating variables and differences in sleep assessment methods, thereby bolstering support for previously documented literature on the ADHD and sleep connection.

University Students' Sleep and Mental Health Correlates in South Korea

Sleep closely relates to emotional instability. Recent studies report an increase in young adults’ poor sleep and associated mental health problems, including attention deficit hyperactivity disorder (ADHD), anxiety, depression, and so on. However, the information on related modifiable factors of these variables is still lacking. This cross-sectional study examined the association of sleep patterns and sleep quality with ADHD and depression in university students. A total of 290 participants aged 18−27 (Mean = 22.0, SD = 2.1) completed a structured questionnaire consisting of the Pittsburgh Sleep Quality Index (PSQI), the Adult ADHD, and the Center for Epidemiologic Studies Depression scales (CES-D). Of the participants, more than half (52.7%) slept 6 to 8 h per night, and 37% slept less than 6 h. Only 10% reported they went to bed before midnight; 40% went to sleep after 2 am. The mean PSQI score was 5.9 (SD = 2.9) for total participants and significantly correlated with ADHD scores and with depression scores. After adjusting for covariates, PSQI significantly aligned with increased risk for ADHD (β = 0.29, p = 0.036) and depression (β = 0.67; p < 0.001). Late bedtime was a significant factor for depression only. Sleep quality rather than sleep pattern significantly related to ADHD scores, whereas both sleep quality and bedtime aligned with depression scores. Additional studies are needed to develop strategic interventions for university students with ADHD and depression as well as underlying mechanisms.

Attention Deficit Hyperactivity Disorder Medications and Sleep

Sleep problems are common and often increase when initiating pharmacotherapy for ADHD. Stimulants are commonly associated with delayed sleep onset/insomnia although nonstimulants can be associated with daytime sleepiness. There is a wide variability in severity and duration of sleep effects, but most effects are mild and improve over time. Although sleep problems occur in all age groups, preschoolers and adolescents appear to be more vulnerable to adverse effects on sleep than adults and children. Interventions to improve sleep include behavioral therapy, changing dose schedules or formulations, and adding a sleep-promoting agent such as melatonin.

Melatonin Rhythm and Its Relation to Sleep and Circadian Parameters in Children and Adolescents With Autism Spectrum Disorder

Introduction

Sleep problems are prevalent among individuals with autism spectrum disorder (ASD), and a role has been attributed to melatonin in this multifactorial comorbidity.

Methods

A cross-sectional study was conducted on 41 autistic children and adolescents (9.9 ± 3.02) and 24 children and adolescents with a normal intellectual function (8.42 ± 2.43) were used as controls. Subjects were matched for sex, body mass index, and pubertal stage, and all were drug-naive. Circadian and sleep parameters were studied using an ambulatory circadian monitoring (ACM) device, and saliva samples were collected around the onset of sleep to determine dim light melatonin onset (DLMO).

Results

Prepubertal individuals with ASD presented later DLMO and an earlier decline in melatonin during adolescence. A relationship was found between melatonin and both sleep and circadian parameters. Participants and controls with later DLMOs were more likely to have delayed sleep onset times. In the ASD group, subjects with the later daytime midpoint of temperature had a later DLMO. Later melatonin peak time and DLMO time were related to lower general motor activity and lower stability of its rhythms.

Conclusion

The melatonin secretion pattern was different in individuals with ASD, and it showed a relationship with sleep and circadian parameters. Alterations in DLMO have not been previously reported in ASD with the exception of more variable DLMO timing; however, high variability in the study design and sample characteristics prevents direct comparison. The ACM device enabled the measurement of circadian rhythm, a scarcely described parameter in autistic children. When studied in combination with other measures such as melatonin, ACM can offer further knowledge on sleep problems in ASD.

Sleep microstructure in attention deficit hyperactivity disorder according to the underlying sleep phenotypes

The analysis of sleep microstructure in attention deficit hyperactivity disorder (ADHD) revealed an under-representation of the EEG slow component during NREM sleep. Previous studies either excluded or did not characterize objectively sleep disorders, which notoriously affect sleep architecture. The present study aimed to investigate the cyclic alternating pattern in a real clinical sample of children with ADHD, in whom sleep disorders could be considered. Twenty-seven consecutively enrolled drug-naïve children (mean age, 10.53 years; nine females) and 23 controls (mean age, 10.22 years; 11 females) underwent a full sleep investigation, including attended video-polysomnography. Visual cyclic alternating pattern analysis was performed in a blinded way. Children with ADHD had one or more sleep disorders (a narcolepsy-like phenotype was found in two cases, sleep onset insomnia in three cases, arousal disorder in one case, movement disorder phenotype in six cases and obstructive sleep apnea in 11 cases, and six children had sleep-related epileptiform discharges). Children with ADHD and normal controls showed a similar microstructure with a cyclic alternating pattern rate of about 50%. Children with obstructive sleep apnea had a significantly higher cyclic alternating pattern rate during stage N3. Despite not reaching statistical differences, a lower cyclic alternating pattern rate and A1 index were found in children without epileptic abnormalities/obstructive sleep apnea. Our analysis might allow differentiation of the "primary form" of ADHD associated with a decrease of NREM instability from those forms associated with sleep apnea and epileptic activity.

Sleep in Individuals with ADHD: Prevalence, Impacts, Causes, and Treatments

Sleep problems are common in children and adolescents with ADHD. This chapter covers the basics of sleep and the prevalence and types of sleep problems experienced by children and adolescents with ADHD. The impacts of sleep problems on the day-to-day lives of children with ADHD and their families are covered including impacts on child daily functioning and cognition, as well as family well-being. There is no one cause of sleep problems in children with ADHD with both biological and environmental factors implicated. There are a small number of randomized controlled trials that support the efficacy of treating sleep problems in children with ADHD using behavioral strategies. A small number of studies also have found improvements in sleep onset delay in children with ADHD following treatment with melatonin. Little is known about how to best support adolescents and adults with ADHD with sleep, although a small emerging literature largely in adults with ADHD suggests that bright light therapies could potentially be helpful given the extent of circadian involvement in the sleep problems experienced by individuals with ADHD. This chapter ends with consideration of future research directions largely related to approaches to supporting individuals with ADHD and sleep difficulties.

ADHD subtypes are associated differently with circadian rhythms of motor activity, sleep disturbances, and body mass index in children and adolescents: a case-control study

To date, few studies have examined the circadian pattern of motor activity in children and adolescents newly diagnosed with attention-deficit/hyperactivity disorder (ADHD). The objective was to study the circadian pattern of motor activity in subjects with ADHD (medication naïve) and to investigate the relationships between alterations in circadian patterns, the ADHD subtype (combined or inattentive), sleep disturbances and body mass index (BMI). One-hundred twenty children and adolescents (60 medication naïve ADHD and 60 controls) were included in a gender- and age-matched case-control study. ADHD was diagnosed according to the DSM-IV-TR, the Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version, and the Conner's Parents Rating Scale-Revised. Circadian rhythms of motor activity and sleep parameters were measured using actigraphy and the Sleep Disturbance Scale for Children. BMI and dietary intake were also evaluated. ADHD patients showed a trend towards eveningness and greater sleep disturbances than controls. Additionally, patients with ADHD-combined had significantly higher mean values of motor activity and showed a significant delay in bedtime. Furthermore, among ADHD-C patients hyperactivity symptoms were significantly associated with the least 5 h of activity. Regarding patients with ADHD-inattentive, increased fragmentation of the circadian pattern was associated with inattention symptoms, and they also showed a significant increase in BMI of 2.52 kg/m² [95% CI 0.31, 4.73] in comparison with controls. Our findings highlight the potential use of actigraphy as a clinical tool to aid in the diagnosis of ADHD. It should be noted that evaluating motor activity variables could also allow the differentiation between ADHD subtypes.

Actigraphy-Derived Sleep Profiles of Children with and without Attention-Deficit/Hyperactivity Disorder (ADHD) over Two Weeks-Comparison, Precursor Symptoms, and the Chronotype

Although sleep problems are common in children with ADHD, their extent, preceding risk factors, and the association between neurocognitive performance and neurobiological processes in sleep and ADHD, are still largely unknown. We examined sleep variables in school-aged children with ADHD, addressing their intra-individual variability (IIV) and considering potential precursor symptoms as well as the chronotype. Additionally, in a subgroup of our sample, we investigated associations with neurobehavioral functioning (n = 44). A total of 57 children (6-12 years) with (n = 24) and without ADHD (n = 33) were recruited in one center of the large ESCAlife study to wear actigraphs for two weeks. Actigraphy-derived dependent variables, including IIV, were analyzed using linear mixed models in order to find differences between the groups. A stepwise regression model was used to investigate neuropsychological function. Overall, children with ADHD showed longer sleep onset latency (SOL), higher IIV in SOL, more movements during sleep, lower sleep efficiency, and a slightly larger sleep deficit on school days compared with free days. No group differences were observed for chronotype or sleep onset time. Sleep problems in infancy predicted later SOL and the total number of movements during sleep in children with and without ADHD. No additional effect of sleep problems, beyond ADHD symptom severity, on neuropsychological functioning was found. This study highlights the importance of screening children with ADHD for current and early childhood sleep disturbances in order to prevent long-term sleep problems and offer individualized treatments. Future studies with larger sample sizes should examine possible biological markers to improve our understanding of the underlying mechanisms.

Review: Identification and Management of Circadian Rhythm Sleep Disorders as a Transdiagnostic Feature in Child and Adolescent Psychiatry

OBJECTIVE

Sleep disturbances are highly frequent features in a range of child and adolescent psychiatric conditions. However, it is commonly not clear if such sleep problems represent symptomatic features of, comorbidities of, or risk factors for these conditions. It is believed that underlying dysfunction in the daily biological (circadian) clock may play important roles in the etiology of many sleep disorders, and circadian rhythm changes are reported in a number of neuropsychiatric conditions. The aim of this review was to explore the key identifying features of circadian rhythm disorders (CRDs) in child and adolescent psychiatry and address how such disorders may be managed in the clinic.

METHOD

A narrative review was conducted of the extant literature of CRDs in children and adolescents with psychiatric conditions.

RESULTS

Key biological and social factors that contribute to CRDs in children and adolescents, and the cognitive and neurobehavioral consequences resulting from insufficient sleep were outlined. The roles of melatonin and other chronotherapeutic and behavioral interventions for the management of CRDs were also outlined. Further, the importance of careful investigation of circadian rhythm abnormalities in shaping the most effective treatment plan according to chronobiological principles was highlighted.

CONCLUSION

CRDs are common in children and adolescents with psychiatric conditions and arise out of complex interactions between biological and social factors. Careful clinical attention to and management of CRDs in child and adolescent psychiatry have the potential for significant benefit not only in the domain of sleep but also in a range of cognitive, affective, and behavioral outcomes.

The impact of lockdown on sleep patterns of children and adolescents with ADHD

STUDY OBJECTIVES

The current study examined the impact of home confinement (lockdown) because of the COVID-19 pandemic on the sleep patterns of children and adolescents with attention-deficit hyperactivity disorder (ADHD).

METHODS

Nine hundred ninety-two parents of children and adolescents with ADHD filled out an anonymous online survey through the ADHD family association website. The survey investigated the sleep patterns and disturbances (using a modified version of the Sleep Disturbance Scale for Children) and screen exposure time before and during lockdown.

RESULTS

During lockdown, 59.3% of children and 69.4% of adolescents with ADHD reported a change of bedtime, with a significant increase in patients with ADHD who went to sleep at 11 pm or later. Sleep duration, in contrast, resulted in 2 opposing processes with more children and adolescents sleeping either less than 6 hours/night or 10-11 hours/night. Among children and adolescents, respectively, 19.9% and 22% slept less than they did before lockdown, whereas 21.4% and 27.4% slept for more hours. Bedtime delay and decreased sleep duration were associated with an increase in screen time exposure. Moreover, patients with ADHD reported an increase in sleep disturbances when compared to their previous condition, mainly including difficulties falling asleep, anxiety at bedtime, night awakenings, nightmares, and daytime sleepiness.

CONCLUSIONS

Lockdown impacted sleep-wake rhythms by strengthening the maladaptive sleep patterns reported in usual-life conditions in children and adolescents with ADHD.

CITATION

Bruni O, Giallonardo M, Sacco R, Ferri R, Melegari MG. The impact of lockdown on sleep patterns of children and adolescents with ADHD. J Clin Sleep Med. 2021;17(9):1759-1765.

Vitamin D levels in children with attention deficit hyperactivity disorder: Association with seasonal and geographical variation, supplementation, inattention severity, and theta:beta ratio

We examined seasonal and geographic effects on vitamin D [25(OH)D] levels, association with attention-deficit/hyperactivity disorder (ADHD) symptom severity, and effects of supplementation in 222 children age 7-10 with rigorously diagnosed ADHD. 25(OH)D insufficiency rates were 47.2 % in Ohio and 28.5 % 400 miles south in North Carolina. Nadir of 25(OH)D levels was reached by November in Ohio, not until January in NC. Thirty-eight children with insufficiency/deficiency took vitamin D (1000-2000 IU/day for a month); levels rose 52 %. Although inattention did not correlate with 25(OH)D at screen nor improve significantly with supplementation, inattention improvement after supplementation correlated with 25(OH)D increase (rho = 0.41, p = 0.012). A clinically significant proportion of children with ADHD have insufficient 25(OH)D even at summer's end, more so in the winter and north of the 37th parallel. The significant correlation of inattention improvement with 25(OH)D increase suggests further research on 25(OH)D as ADHD treatment.

Current Evidence on the Role of the Gut Microbiome in ADHD Pathophysiology and Therapeutic Implications

Studies suggest that the bidirectional relationship existent between the gut microbiome (GM) and the central nervous system (CNS), or so-called the microbiome–gut–brain axis (MGBA), is involved in diverse neuropsychiatric diseases in children and adults. In pediatric age, most studies have focused on patients with autism. However, evidence of the role played by the MGBA in attention deficit/hyperactivity disorder (ADHD), the most common neurodevelopmental disorder in childhood, is still scanty and heterogeneous. This review aims to provide the current evidence on the functioning of the MGBA in pediatric patients with ADHD and the specific role of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) in this interaction, as well as the potential of the GM as a therapeutic target for ADHD. We will explore: (1) the diverse communication pathways between the GM and the CNS; (2) changes in the GM composition in children and adolescents with ADHD and association with ADHD pathophysiology; (3) influence of the GM on the ω-3 PUFA imbalance characteristically found in ADHD; (4) interaction between the GM and circadian rhythm regulation, as sleep disorders are frequently comorbid with ADHD; (5) finally, we will evaluate the most recent studies on the use of probiotics in pediatric patients with ADHD.

The Role of the Circadian System in Attention Deficit Hyperactivity Disorder

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental condition characterised by the core symptoms of inattention, impulsivity and hyperactivity. Similar to many other neuropsychiatric conditions, ADHD is associated with very high levels of sleep disturbance. However, it is not clear whether such sleep disturbances are precursors to, or symptoms of, ADHD. Neither is it clear through which mechanisms sleep and ADHD are linked. One possible link is via modulation of circadian rhythms. In this chapter we overview the evidence that ADHD is associated with alterations in circadian processes, manifesting as later chronotype and delayed sleep phase in ADHD, and examine some mechanisms that may lead to such changes. We also interrogate how the circadian clock may be a substrate for therapeutic intervention in ADHD (chronotherapy) and highlight important new questions to be addressed to move the field forward.

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.

Cumulative incidence and relative risk of sleep problems among children and adolescents with newly diagnosed neurodevelopmental disorders: A nationwide register-based study

We estimated the absolute and relative risk of sleep problems in children and adolescents with newly diagnosed neurodevelopmental disorders. This was a population-based cohort study of individuals born in Denmark in 1993-2014 and followed in nationwide registers in 2011-2016. We estimated the 5-year cumulative incidence of sleep problems in incident cases of attention-deficit/hyperactivity disorder (ADHD; n = 12,844), autism spectrum disorder (ASD; n = 8,073), oppositional defiant disorder/conduct disorder (ODD/CD; n = 2,234) and epilepsy (n = 3,709). Hazard ratios (HRs) for sleep problems were estimated by Cox regression. The 5-year risk of sleep problems was highest in ADHD (29.2%; 95% CI, 28.4-30.1), ASD (24.2%; 95% CI, 23.1-25.3) and ODD/CD (27.1% 95% CI, 25.0%-29.2%) and lowest in epilepsy (11.3%; 95% CI, 10.2%-12.6%). For ADHD and ASD, sleep problems were more common in females than in males. Furthermore, sleep problems were predicted by high parental socioeconomic status and varied with the geographical region of residence, suggesting that different clinical practices exist across Denmark and that sleep problems may be more likely to go undetected in families of lower socioeconomic position. Compared with individuals without these disorders, the likelihood of sleep problems was increased in individuals with ADHD (HR, 33.81; 95% CI, 32.78-34.87), ASD (HR, 16.77; 95% CI, 16.15-17.41), ODD/CD (HR, 14.73; 95% CI, 13.88-15.64) and epilepsy (HR, 6.01; 95% CI, 5.67-6.37). After mutual adjustment for comorbidity, HRs were attenuated, especially in ASD, ODD/CD and epilepsy when adjusted for ADHD, suggesting that the increased risk of sleep problems in individuals with ASD, ODD/CD and epilepsy is driven largely by comorbid ADHD.

In Quest of Pathognomonic/Endophenotypic Markers of Attention Deficit Hyperactivity Disorder (ADHD): Potential of EEG-Based Frequency Analysis and ERPs to Better Detect, Prevent and Manage ADHD

Attention deficit hyperactivity disorder (ADHD) is a chronic heritable developmental delay psychiatric disorder requiring chronic management, characterized by inattention, hyperactivity, hyperkinectivity and impulsivity. Subjective clinical evaluation still remains crucial in its diagnosis. Discussed are two key aspects in the “characterizing ADHD” and on the quest for objective “pathognomonic/endophenotypic diagnostic markers of ADHD”. The first aspect briefly revolves around issues related to identification of pathognomonic/endophenotypic diagnostic markers in ADHD. Issues discussed include changes in ADHD definition, remission/persistence and overlapping-symptoms cum shared-heritability with its co-morbid cross-border mental disorders. The second aspect discussed is neurobiological and EEG-based studies on ADHD. Given the neurobiological and temporal aspects of ADHD symptoms the electroencephalograph (EEG) like NeuralScan by Medeia appears as an appropriate tool. The EEGs appropriateness is further enhanced when coupled with suitable behavior/cognitive/motor/psychological tasks/paradigms yielding EEG-based markers like event-related-potential (ERPs like P3 amplitudes and latency), reaction time variability (RTV), Theta:Beta ratio (TBR) and sensorimotor rhythm (SMR). At present, these markers could potentially help in the neurobiological characterization of ADHD and either help in identifying or lay the groundwork for identifying pathognomonic and/or endophenotypic EEG-based markers enabling its diagnosis, treatment and management.

Efficacy and Safety of Melatonin Treatment in Children with Autism Spectrum Disorder and Attention-Deficit/Hyperactivity Disorder-A Review of the Literature

Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) are neurodevelopmental disorders with disturbed melatonin secretion profile and sleep problems. The growing incidence of ASD and ADHD inspires scientists to research the underlying causes of these conditions. The authors focused on two fundamental aspects, the first one being the presentation of the role of melatonin in ASD and ADHD and the second of the influence of melatonin treatment on sleep disorders. The authors present the use of melatonin both in the context of causal and symptomatic treatment and discuss melatonin supplementation: Dosage patterns, effectiveness, and safety. Sleep disorders may have a different clinical picture, so the assessment of exogenous melatonin efficacy should also refer to a specific group of symptoms. The review draws attention to the wide range of doses of melatonin used in supplementation and the need to introduce unified standards especially in the group of pediatric patients.

The potential role of clock genes in children attention-deficit/hyperactivity disorder

BACKGROUND

Attention deficit/ hyperactivity disorder (ADHD) is a chronic neurodevelopmental disorder and is thought to be associated with circadian system.

METHODS

We performed a pathway-based study to test individual single nucleotide polymorphisms (SNPs) and the overall evidence of genetic polymorphisms involved in the circadian pathway in association with children ADHD susceptibility among a Chinese population. A community-based case-control study was conducted among Chinese children, and 168 ADHD patients and 233 controls were recruited using a combination diagnosis based on the diagnostic and statistical manual of mental disorders iv (DSM-IV) ADHD rating scale, Swanson, Nolan, and Pelham rating scale (SNAP-IV) rating scale, and semi-structured clinical interview.

RESULTS

The results of single-loci analyses identified that PER1 rs2518023 and ARNTL2 rs2306074 were nominally association with ADHD susceptibility (P < 0.05). Next, we applied multifactor dimensionality reduction (MDR), and classification and regression tree (CART) analyses to explore high-order gene-gene interactions among the functional SNPs to ADHD risks. The results indicated that interactions among the PER1 rs2518023, ARNTL2 rs2306074 and NR1D1 rs939347 were associated with the risk of ADHD in children. Individuals carrying the combination genotypes of the PER1 rs2518023 GG or GT, ARNTL2 rs2306074 TC or TT and NR1D1 rs939347 GA or AA displayed a significantly higher risk for ADHD than who carry the PER1 rs2518023 TT and CRY2 rs2292910 CA/CC genotypes (adjusted OR = 4.37, 95% CI = 2.16-8.85, P < 0.001).

CONCLUSIONS

These findings revealed the importance of genetic variations related to the circadian clock system to the susceptibility of children ADHD.

ADHD 24/7: Circadian clock genes, chronotherapy and sleep/wake cycle insufficiencies in ADHD

Objectives: The current paper addresses the evidence for circadian clock characteristics associated with attention-deficit hyperactivity disorder (ADHD), and possible therapeutic approaches based on chronomodulation through bright light (BL) therapy.Methods: We review the data reported in ADHD on genetic risk factors for phase-delayed circadian rhythms and on the role of photic input in circadian re-alignment.Results: Single nucleotide polymorphisms in circadian genes were recently associated with core ADHD symptoms, increased evening-orientation and frequent sleep problems. Additionally, alterations in exposure and response to photic input may underlie circadian problems in ADHD. BL therapy was shown to be effective for re-alignment of circadian physiology toward morningness, reducing sleep disturbances and bringing overall improvement in ADHD symptoms. The susceptibility of the circadian system to phase shift by timed BL exposure may have broad cost-effective potential implications for the treatment of ADHD.Conclusions: We conclude that further research of circadian function in ADHD should focus on detection of genetic markers (e.g., using human skin fibroblasts) and development of BL-based therapeutic interventions.

Media Use, Sleep Quality, and ADHD Symptoms in a Community Sample and a Sample of ADHD Patients Aged 8 to 18 Years

Objective: Relationships between sleep, screen-based media, and ADHD symptomatology were investigated using a case- and community-based approach. Method: N = 357 healthy and N = 61 children with ADHD (12.72 ± 2.83 years) completed a sleep and media questionnaire. To measure ADHD symptomatology, parents filled out the Strengths and Weaknesses of ADHD symptoms and Normal behavior (SWAN) scale. Two samples were formed: a matched (N = 61 patients and N = 61 controls) and a community sample (N = 357 healthy participants and N = 20 patients). Results: Compared with controls, participants with ADHD reported delayed sleep onset and more screen time on school days. Adolescent patients showed more behavior promoting delayed sleep phase. In the community sample, media time, sleep deviation, and circadian rhythm were correlated with ADHD symptomatology. Furthermore, media time, sleep-wake behavior, and sleep deviation were predictive of ADHD symptomatology (variance explained = 4%-15%). Conclusion: Longer media time and inadequate sleep-wake behavior increase the risk of ADHD-like symptoms. However, research using objective assessments is needed to disentangle this distinct association and to provide possible directions for intervention.

Associations Between Sleep Hygiene and Sleep Problems in Adolescents With ADHD: A Cross-Sectional Study

Objective: To determine whether self-reported sleep hygiene practices are associated with self- and parent-reported behavioral sleep problems in adolescents with ADHD. Method: Participants included 79 adolescents with ADHD (13-17 years) and their parents. Adolescents were asked to report on their sleep hygiene (Adolescent Sleep Hygiene Scale) and sleep (Adolescent Sleep Wake Scale). Parents also reported on their adolescent's sleep (Sleep Disturbance Scale for Children). Results: Poorer sleep hygiene was associated with higher total self-reported behavioral sleep problems and most self-reported sleep problems: falling asleep, reinitiating sleep, and returning to wakefulness. The association was also apparent for total parent-reported behavioral sleep problems, problems with initiating and maintaining sleep, and excessive somnolence. Conclusion: This study demonstrates small-to-moderate relationships between poor sleep hygiene practices and sleep problems in adolescents with ADHD, by both self- and parent-report.

Feasibility of a Complex Setting for Assessing Sleep and Circadian Rhythmicity in a Fragile X Cohort

INTRODUCTION

Sleep, circadian rhythms, (mental) health, and development are assumed to be intertwined. However, differentiated and reliable parameters of sleep and circadian rhythms are particularly difficult to assess for Fragile X (FXS) individuals. As those parameters need to be observed in complex settings, the feasibility of measurements for people with FXS was to be proven. Findings from this pilot study can inform further research and help to estimate sample sizes for future studies on FXS patients.

METHODS AND SAMPLE

Nine individuals (male and female) with full mutation of the FMR1 gene were integrated in the study and underwent a complex measurement including actigraphy, sleep log, and 24-h saliva sampling in order to examine profiles of melatonin and cortisol, and a polysomnography.

RESULTS

Seven actigraphy profiles, eight sleep logs, eight saliva profiles and seven polysomnographic data sets were collected. Complete data were analyzed for six individuals [mean age 14.87 years (SD 4.12), mean BMI 25.90 (SD 4.44)] were collected. No drop outs due to the constraints of the assessment were registered.

DISCUSSION

All assessments and the setting in total were tolerated well by participants and caregivers. Procedures were adapted to individual needs of the participants.

CONCLUSION

All its components and the setting in total are absolutely feasible in the specific population of FXS individuals. Losses during consenting and recruiting have to be planned as well as high amounts of interindividual variances have to be taken into account.

Associations between parenting stress, parent mental health and child sleep problems for children with ADHD and ASD: Systematic review

BACKGROUND

Children with attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) experience high rates of sleep problems. Their parents experience higher parenting stress and more mental health difficulties than parents of typically developing children.

AIM

To examine the association between child sleep problems, parenting stress and parent mental health for children with ADHD or ASD.

METHODS

MEDLINE Complete, EMBASE, PsycINFO and CINAHL Complete databases were searched. Studies needed to include: children aged 5-18 with ADHD or ASD, a child sleep measure, and a parenting stress or adult mental health measure.

RESULTS

Eleven studies were identified (four ADHD, seven ASD). Six studies examined parenting stress (five cross-sectional, one longitudinal) and five found associations, of varying strengths, with child sleep problems. Six studies examined parent mental health (four cross-sectional, two longitudinal) and five found associations, of differing magnitudes, with child sleep problems.

CONCLUSIONS

These studies demonstrate child sleep problems are associated with poorer parent mental health and higher parenting stress.

IMPLICATIONS

Future longitudinal research including multiple measurements of child sleep problems and family functioning is required to clarify the directionality of associations. Such knowledge is key in adapting sleep interventions to better meet the needs of children with ADHD or ASD and their families.

Association of inattention with slow-spindle density in sleep EEG of children with attention deficit-hyperactivity disorder

OBJECTIVE

We evaluated the power of slow sleep spindles during sleep stage 2 to clarify their relationship with executive function, especially with attention, in children with attention deficit-hyperactivity disorder (ADHD).

METHODS

Subjects were 21 children with ADHD and 18 aged-matched, typically developing children (TDC). ADHD subjects were divided into groups of only ADHD and ADHD + autism spectrum disorder (ASD). We employed the Continuous Performance Test (CPT) to measure attention. We focused on sleep spindle frequencies (12-14 Hz) in sleep stage 2 and performed a power spectral analysis using fast Fourier transform techniques and compared sleep spindles with the variability of reaction time in CPT.

RESULTS

In the CPT, reaction variabilities in ADHD and ADHD + ASD significantly differed from those in TDC. Twelve-hertz spindles were mainly distributed in the frontal pole and frontal area and 14-Hz spindles in the central area. The ratio of 12-Hz frontal spindle power was higher in ADHD than in TDC, especially in ADHD + ASD. Significant correlation between the ratio of 12-Hz spindles and reaction time variability was observed.

CONCLUSIONS

Twelve-hertz frontal spindle EEG activity may have positive associations with sustained attention function. Slow frontal spindles may be useful as a biomarker of inattention in children with ADHD.

ADHD and sleep: recent advances and future directions

Individuals with attention-deficit/hyperactivity disorder (ADHD) frequently have sleep disturbances, daytime sleepiness, and/or circadian rhythm abnormalities. This article reviews recent advancements and key future directions: examining group differences across the life span, advancing a developmental psychopathology perspective, moving from correlation to causation, conceptualizing ADHD as a 24-hour disorder, understanding sleep in relation to other health behaviors, and evaluating sleep in interventions for individuals with ADHD. This is an exciting time in the empirical study and clinical care of sleep disturbances and circadian rhythm alterations in individuals with ADHD. As research continues to advance, studies are increasingly using large samples and longitudinal/experimental research designs to test hypotheses that will ultimately allow for a more robust and sophisticated understanding of sleep and ADHD.

The relationship between chronotype and obesity in children and adolescent with attention deficit hyperactivity disorder

Children and adolescents with Attention Deficit Hyperactivity Disorder (ADHD) have a high prevalence of obesity, but the relationship between these two problems is not clear. Chronotype preferences may be one of the possible mechanisms underlying the link between ADHD and obesity. This is the first study to investigate whether chronotype preferences are a mechanism linking ADHD symptoms to obesity in children and adolescents. This cross-sectional study included 110 drug-naive children and adolescents aged 7-17 years with ADHD. The Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version (K-SADS-PL) was used to diagnose ADHD or to exclude psychiatric comorbidity. The Conners' Parents Rating Scale-Revised Short Version (CPRS-RS) and Children's Chronotype Questionnaire (CCQ) were used to assess the severity of ADHD symptoms and chronotype preferences. Body mass index (BMI) was calculated and classified according to national age- and gender-specific reference values. The participants were divided into three groups as normal weight (<85%, n = 38), overweight (85%-95%, n = 30) and obesity (>95%, n = 42) according to their BMI percentile. There were statistically significant differences between the three groups in terms of chronotype preference (p = .000). Morningness preference was 86.84% in the normal BMI group and 26.19% in the obese BMI group. Eveningness preference was 7.89% in the normal BMI group and 61.90% in the obese BMI group. There was a correlation between the BMI percentile scores and the morningness/eveningness scale (M/E) scores. Moreover, there was a correlation between the BMI percentile scores and the oppositional and ADHD index scores. According to logistic regression analysis, the odds ratio of having evening type for obesity was 5.66 and the odds ratio of having morning type for normal weight was 13.03. Independently from ADHD symptoms, eveningness was directly related to obesity and morningness was directly related to normal weight. Prospective studies should be performed to better understand the relationship between ADHD, overweight/obesity and chronotype.

[Diagnosis and comorbidities of Circadian Rhythm Sleep Disorders]

Circadian rhythm sleep disorders (CRSD) result from a disturbed endogenous clock (intrinsic CRSD) or from a misalignment between the biological clock and an imposed environment (extrinsic CRSD). Among intrinsic CRSD, one distinguishes the delayed sleep-wake phase disorder, the advanced sleep-wake phase disorder, the irregular sleep-wake rhythm disorder and the non-24-hour sleep-wake rhythm disorder. Shift work disorder, jet lag disorder and circadian sleep-wake disorder not otherwise specified are extrinsic CRSD. Prevalences of the different CRSD remain largely unknown. Some CRSD are particularly frequent such as sleep delayed phase syndrome in adolescents. Overall, CRSD are probably under-diagnosed. CRSD generate insomnia and excessive daytime somnolence. A biological clock dysfunction has to be evoked in case of insomnia or sleepiness. Furthermore, as CRSD can overlap with other sleep disorders, their diagnosis and treatment are essential. CRSD cause significant mental, physical or socio-professional sufferings. They are frequently associated with comorbidities, mainly neurodevelopmental, psychiatric and neurodegenerative disorders. Regarding neurodevelopmental comorbidities, therapy using a chronobiological approach is complementary to the usual clinical care. It helps to limit the significant impact of CRSD on quality of live, daytime functioning, social interactions and neurocognitive difficulties in the children. In psychiatry, sleep disorders and circadian rhythms sleep-wake disorders are a factor of vulnerability, of suicidal risk, of relapse and pharmacoresistance. Thus, diagnosis of CRSD associated with a psychiatric disorder is of major importance. Treatment using a chronobiological approach reinforcing the entrainment of the sleep-wake cycle is complementary to usual treatments. Sleep disorders and circadian sleep-wake rhythm disorders can be a preclinical sign of Alzheimer's and Parkinson's disease. In the elderly, a beginning neurodegenerative disorder can be associated with a CRSD and complaints of sleepiness, nocturnal awakenings and/or irregular sleep-wake cycles. Patients affected by neurogenerative disorders are particularly vulnerable for having CRSD. Data from different studies suggest that CRSD participate in pathophysiology of Alzheimer's disease. Even though treatment of CRSD associated with neurodegenerative disorders is entirely part of the treatment strategy, it remains uncertain to which extend this treatment may impact disease progression.

Melatonin inhibits attention-deficit/hyperactivity disorder caused by atopic dermatitis-induced psychological stress in an NC/Nga atopic-like mouse model

Atopic dermatitis (AD) is a chronic inflammatory skin disease with the hallmark characteristics of pruritus, psychological stress, and sleep disturbance, all possibly associated with an increased risk of attention-deficit/hyperactivity disorder (ADHD). However, the etiology of the possible association between AD and ADHD is still not well understood. 2,4-dinitrochlorobenzene or corticosterone was used to evaluate the atopic symptom and its psychologic stress in the atopic mice model. Melatonin, corticotropin-releasing hormone, corticotropin-releasing hormone receptor, urocortin, proopiomelanocortin, adrenocorticotropic hormone, corticosterone, cAMP, cAMP response element-binding protein, dopamine and noradrenaline were analyzed spectrophotometrically, and the expression of dopamine beta-hydroxylase and tyrosine hydroxylase were measured by Western blotting or immunohistochemistry. AD-related psychological stress caused an increase in the levels of dopamine beta-hydroxylase and tyrosine hydroxylase, degradation of melatonin, hyper-activity of the hypothalamic-pituitary-adrenal axis, and dysregulation of dopamine and noradrenaline levels (ADHD phenomena) in the locus coeruleus, prefrontal cortex, and striatum of the AD mouse brain. Notably, melatonin administration inhibited the development of ADHD phenomena and their-related response in the mouse model. This study demonstrated that AD-related psychological stress increased catecholamine dysfunction and accelerated the development of psychiatric comorbidities, such as ADHD.

Time-shifting effects of methylphenidate on daily rhythms in the diurnal rodent Arvicanthis ansorgei

People suffering of attention-deficit/hyperactivity disorder (ADHD) and treated with the psychostimulant methylphenidate (MPH) show sleep-wake cycle and daily rhythm alterations despite the beneficial effects of MPH on behavioral symptoms (i.e., hyperactivity, attention). In nocturnal rodents (i.e., mice), chronic exposure to MPH alters the neural activity of the circadian clock in the suprachiasmatic nucleus (SCN), behavioral rhythms, and the sleep-wake cycle. Here, we studied the effects of MPH on daily rhythms of behavior and body temperature of the diurnal rodent Arvicanthis ansorgei. Under a light-dark cycle, chronic exposure to MPH in drinking water delayed the onset of both activity and body temperature rhythms. Interestingly, delays were larger when MPH access was restricted to the first 6 h of the light phase (i.e., activity phase) of the 24-h cycle. Since MPH effects are dependent on animal's fluid intake, in a last experiment, we controlled the time and dose of MPH delivery in Arvicanthis using an intraperitoneal perfusion method. Similarly to the experiment with MPH in drinking water, Arvicanthis showed a delay in the onset of general activity and body temperature when MPH infusions, but not vehicle, were during the first 6 h of the light phase. This study indicates that MPH alters daily rhythms in a time-dependent manner and proposes the use of a diurnal rodent for the study of the effects of MPH on the circadian clock. Knowing the circadian modulation on the effects of MPH in behavior could give new insights in the treatment of ADHD.