Is there a specific polysomnographic sleep pattern in children with attention deficit/hyperactivity disorder?

Sex Differences in Children with Uncomplicated Attention Deficit/Hyperactivity Disorder and Sleep Problems

BACKGROUND

Approximately 7.6% of children are diagnosed with attention deficit/hyperactivity disorder (ADHD), and sleep impairments affect 25-85%. There is a noticeable lack of research on girls and sex differences. The aim of this study was to examine sex differences in children with uncomplicated ADHD and sleep problems.

METHODS

Cross-sectional baseline data were retrieved from a randomized controlled trial with weighted blankets (55 boys and 41 girls, 6-14 years) on a cohort recently diagnosed with uncomplicated ADHD and sleep problems. Differences between boys and girls in ADHD symptoms, objectively and subjectively measured sleep, anxiety, and functioning were examined via parent- or self-reported validated instruments.

RESULTS

Girls reported significantly lower (worse) satisfaction with well-being, life overall, and school, but not for family. Parents reported more sleep anxiety and night-time wakings among boys, but no sex differences in other measures and also not in self-reported measures or objective sleep measures. Children who reported worry, sadness, or unhappiness had more sleep problems.

CONCLUSIONS

Boys with ADHD and sleep problems may need support with sleep-related anxiety and night-time wakings, while girls may require support with overall functioning. Additionally, children who express feelings of worry, sadness, or unhappiness alongside their ADHD symptoms should have attention given to their sleep.

Objectively measured sleep continuity in children and adolescents with ADHD: A systematic review and meta-analysis

Sleep disturbances are often linked to attention-deficit/hyperactivity disorder (ADHD). Consistent findings document that children and adolescents with ADHD report more sleep problems than their typically developing (TD) peers across subjective sleep domains. However, few differences between these groups were observed in objectively measured sleep parameters, such as polysomnography (PSG) and actigraphy. This study synthesized empirical studies to identify objectively measured sleep continuity differences between children and adolescents with ADHD and TD. We included observational research and baseline data from intervention studies between 5- to 18-year-old individuals with ADHD and their TD peers at five databases from inception and September 2022. This systematic review and meta-analysis of 45 articles, including 1622 children and adolescents with ADHD and 2013 TD, found that compared with TD, children and adolescents with ADHD have higher sleep latency and moderately decreased sleep efficiency measured by actigraphy. Polysomnography-measured differences between ADHD and TD were not significant. Medication status and comorbid psychiatric status significantly moderated the group differences in sleep efficiency between ADHD and TD. Also, the group differences in sleep latency between ADHD and TD were moderated by actigraphy recorded nights. These findings highlight the importance of reducing disparities in sleep parameters among children and adolescents with and without ADHD.

A failure of sleep-dependent consolidation of visuoperceptual procedural learning in young adults with ADHD

ADHD has been associated with cortico-striatal dysfunction that may lead to procedural memory abnormalities. Sleep plays a critical role in consolidating procedural memories, and sleep problems are an integral part of the psychopathology of ADHD. This raises the possibility that altered sleep processes characterizing those with ADHD could contribute to their skill-learning impairments. On this basis, the present study tested the hypothesis that young adults with ADHD have altered sleep-dependent procedural memory consolidation. Participants with ADHD and neurotypicals were trained on a visual discrimination task that has been shown to benefit from sleep. Half of the participants were tested after a 12-h break that included nocturnal sleep (sleep condition), whereas the other half were tested after a 12-h daytime break that did not include sleep (wakefulness condition) to assess the specific contribution of sleep to improvement in task performance. Despite having a similar degree of initial learning, participants with ADHD did not improve in the visual discrimination task following a sleep interval compared to neurotypicals, while they were on par with neurotypicals during the wakefulness condition. These findings represent the first demonstration of a failure in sleep-dependent consolidation of procedural learning in young adults with ADHD. Such a failure is likely to disrupt automatic control routines that are normally provided by the non-declarative memory system, thereby increasing the load on attentional resources of individuals with ADHD.

Overlapping sleep disturbances in persistent tic disorders and attention-deficit hyperactivity disorder: A systematic review and meta-analysis of polysomnographic findings

INTRODUCTION

Persistent tic disorders (PTDs) and attention-deficit hyperactivity disorder (ADHD) are common neurodevelopmental conditions which tend to co-occur. Both diagnoses are associated with sleep problems. This systematic review and meta-analysis investigates overlaps and distinctions in objective sleep parameters based on diagnosis (PTD-only, PTD + ADHD, and ADHD-only).

METHODS

Databases were searched to identify studies with objective sleep measures in each population. Meta-analyses were conducted using a random effects model.

RESULTS

Polysomnography was the only measure included in all three groups. Twenty studies met final inclusion criteria, combining PTD-only (N = 108), PTD + ADHD (N = 79), and ADHD-only (N = 316). Compared to controls (N = 336), PTD-only and PTD + ADHD groups had significantly lower sleep efficiency and higher sleep onset latency. PTD + ADHD also had significantly increased time in bed and total sleep time. No significant differences were observed between ADHD-only groups and controls.

DISCUSSION

Different sleep profiles appear to characterise each population. PTD + ADHD was associated with more pronounced differences. Further research is required to elucidate disorder-specific sleep problems, ensuring appropriate identification and monitoring of sleep in clinical settings.

Sleep's role in memory consolidation: What can we learn from atypical development?

Research conducted over the last century has suggested a role for sleep in the processes guiding healthy cognition and development, including memory consolidation. Children with intellectual and developmental disabilities (IDDs) tend to have higher rates of sleep disturbances, which could relate to behavior issues, developmental delays, and learning difficulties. While several studies examine whether sleep exacerbates daytime difficulties and attention deficits in children with IDDs, this chapter focuses on the current state of knowledge regarding sleep and memory consolidation in typically developing (TD) groups and those at risk for learning difficulties. In particular, this chapter summarizes the current literature on sleep-dependent learning across developmental disabilities, including Down syndrome, Williams syndrome, Autism Spectrum Disorder, and Learning Disabilities (Attention-Deficit/Hyperactivity Disorder and Dyslexia). We also highlight the gaps in the current literature and identify challenges in studying sleep-dependent memory in children with different IDDs. This burgeoning new field highlights the importance of considering the role of sleep in memory retention across long delays when evaluating children's memory processes. Further, an understanding of typical and atypical development can mutually inform recent theories of sleep's role in memory.

A coordinate-based meta-analysis comparing brain activation between attention deficit hyperactivity disorder and total sleep deprivation

STUDY OBJECTIVES

Sleep disruption is common in attention deficit hyperactivity disorder (ADHD). Likewise, deficits in attention are a hallmark of sleep deprivation in healthy individuals. Whether ADHD and sleep deprivation modulate common, or disparate, neural systems is unknown. No study has yet utilized functional magnetic resonance imaging (fMRI) to investigate sleep loss in ADHD. We address this gap by performing a novel meta-analysis to compare patterns of fMRI activation during sleep deprivation and ADHD.

METHODS

We performed a coordinate-based activation likelihood estimate (ALE) meta-analysis using the GingerALE software. A systematic review of task-based fMRI studies of sleep deprivation vs. rested and also ADHD vs. healthy controls (HC) yielded 134 articles. fMRI coordinates were extracted for each contrast (i.e. "ADHD vs. HC," "TSD vs. Rested") and normalized to the Talairach-atlas. Separate ALE analyses were performed for ADHD and sleep deprivation. We directly compared these initial estimates to determine shared vs. distinct areas of fMRI neural activation in ADHD and sleep deprivation.

RESULTS

Conjunction analyses revealed overlapping hypoactivations between ADHD and sleep loss in executive function regions, notably the dorsal anterior cingulate cortex. Sleep deprivation, however, was associated with significantly exaggerated hyperactivation in the thalamus.

CONCLUSIONS

Our study indicates that ADHD and sleep deprivation share a common neural signature: hypoactivation of executive function neuroanatomy. In contrast, sleep loss, but not ADHD, was associated with thalamic hyperactivations, intimating a potential compensatory response in sleep loss not present in ADHD. By elucidating shared and distinct patterns of functional neuroanatomy, these data provide novel targets for future experimental investigations of sleep loss in ADHD.

Actigraphic Sleep Pattern of Preschoolers With ADHD

Objective: To assess the features of sleep in preschoolers with ADHD by means of questionnaire and actigraphy. Method: Twenty-five ADHD and 21 age-matched typically developing (TD) preschool children underwent the Child Behavior Checklist (CBCL) for ages 1½ to 5 and Pre-School-Age Psychiatric Assessment interview. Sleep was assessed by means of a modified Sleep Disturbance Scale for Children and wrist actigraphy for at least 5 days. Results: Children with ADHD, compared with TD, showed higher scores in CBCL Withdrawal (58.83 vs. 51.15, p < .0001), Attention Problems (69.88 vs. 51.54, p < .0001), and Aggressive Behavior (59.46 vs. 51.08, p < .0001) dimensions; they also showed increased actigraphic nocturnal activity (activity index 31.57 vs. 25.74, p < .05); and night-to-night variability for sleep minutes (56.44 vs. 32.79, p < .01), mean wake episodes (1.34 vs. 0.98, p < .05), mean activity (2.64 vs. 1.71, p < .05), and activity index (5.15 vs. 3.77, p < .05). Conclusion: This pilot study in preschoolers with ADHD showed increased motor activity during sleep and night-to-night variability for sleep duration and motor activity.

Advances in Understanding the Relationship between Sleep and Attention Deficit-Hyperactivity Disorder (ADHD)

Starting from the consolidated relationship between sleep and cognition, we reviewed the available literature on the association between Attention Deficit-Hyperactivity Disorder (ADHD) and sleep. This review analyzes the macrostructural and microstructural sleep features, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria (PRISMA). We included the polysomnographic studies published in the last 15 years. The results of macrostructural parameters are mixed. Almost half of the 18 selected investigations did not find differences between sleep architecture of children with ADHD and controls. Five studies observed that children with ADHD show a longer Rapid Eye Movement (REM) sleep duration than controls. Eight studies included microstructural measures. Remarkable alterations in sleep microstructure of ADHD are related to slow wave activity (SWA) and theta oscillations, respectively, during Non-REM (NREM) and REM sleep. Specifically, some studies found higher SWA in the ADHD group than controls. Similarly, higher theta activity appears to be detrimental for memory performance and inhibitory control in ADHD. These patterns could be interpreted as a maturational delay in ADHD. Also, the increased amount of these activities would be consistent with the hypothesis that the poor sleep could imply a chronic sleep deprivation in children with ADHD, which in turn could affect their cognitive functioning.

Sleep alterations in pediatric bipolar disorder versus attention deficit disorder

Bipolar disorder (BD) and attention deficit/hyperactivity disorder (ADHD) share numerous clinical features, which can make the differential diagnosis challenging. Studies conducted in adults suggest that patients with BD and ADHD have different sleep patterns. However, in pediatric populations, data on these potential differences are scant. The present preliminary study was conducted to identify potential differences in sleep alterations among youths diagnosed with BD or ADHD compared to healthy controls (HC). A total of 26 patients diagnosed with BD (n = 13) or ADHD (n = 13) were compared to 26 sex- and age-matched HC ([HC_BD], n = 13, and [HC_ADHD], n = 13). All participants underwent polysomnography. The mean duration of stage N2 sleep was shorter in the BD group than in controls (HC_BD). The BD group also had higher (non-significant) REM density (REMd) scores than controls while mean REMd scores were lower in the ADHD group versus controls. Compared to the ADHD group, the BD group presented a shorter N2 stage, a longer first REM sleep duration (R1), and greater REMd. According to our findings, these three variables-N2 stage, REMd, and R1-appear to differentiate patients with BD from those with ADHD and from HC.

Sleep Disturbances in Child and Adolescent Mental Health Disorders: A Review of the Variability of Objective Sleep Markers

Sleep disturbances are often observed in child and adolescent mental health disorders. Although previous research has identified consistent subjective reports of sleep disturbances, specific objective sleep markers have not yet been identified. We evaluated the current research on subjective and objective sleep markers in relation to attention deficit hyperactivity disorders, autism spectrum disorders, anxiety and depressive disorders. Subjective sleep markers are more consistent than objective markers of actigraphy, polysomnography, and circadian measures. We discuss the causes of variability in objective sleep findings and suggest future directions for research.

Evaluation of the Relationship Between Attention Deficit Hyperactivity Disorder Symptoms and Chronotype

INTRODUCTION

The aim of the study is to investigate the relationship between circadian characteristics and behavioral problems in children with Attention Deficit Hyperactivity Disorder (ADHD) (n=53), and to compare this group with healthy controls (n=38).

METHOD

Fifty-three medication-free children with ADHD, aged 6-12 years, and 38 healthy children, age and sex matched, participated. Parents completed the Conners' Parent Rating Scale-Revised, the Children's Chronotype Questionnaire (CCTQ), and the Children's Sleep Habits Questionnaire (CSHQ) to assess sleep variables.

RESULTS

ADHD children had more sleep-onset problems and parasomnias (in CSHQ) compared to healthy controls. However, circadian preferences did not differ between the groups in CCTQ scores. Another important finding was a mild correlation between parasomnia, bedtime on schooldays, and ADHD symptoms.

CONCLUSION

Our study showed that children with ADHD showed more resistance to going to bed than did controls on school days. However, in contrast to our hypothesis, morningness/eveningness preference did not differ from controls in ADHD children.

DSM-5 Changes in Attention Deficit Hyperactivity Disorder and Autism Spectrum Disorder: Implications for Comorbid Sleep Issues

Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) are the most common neurodevelopmental disorders. Despite significant comorbidity, the previous diagnostic criteria prohibited the simultaneous diagnosis of both disorders. Sleep problems are highly prevalent in both disorders; however, these have been studied independently for ADHD and ASD. In the context of revised criteria in the Diagnostic Statistical Manual of Mental Disorders 5th edition (DSM-5) that allows combined diagnosis of ADHD and ASD, this short review presents an overview of relationship between sleep problems, ADHD and ASD, as well as conceptualizing the shared pathophysiology. The practical considerations for clinical management of sleep problems in combination with ADHD and ASD are also discussed.

Opposite Impact of REM Sleep on Neurobehavioral Functioning in Children with Common Psychiatric Disorders Compared to Typically Developing Children

Rapid eye movement (REM) sleep has been shown to be related to many adaptive cognitive and behavioral functions. However, its precise functions are still elusive, particularly in developmental psychiatric disorders. The present study aims at investigating associations between polysomnographic (PSG) REM sleep measurements and neurobehavioral functions in children with common developmental psychiatric conditions compared to typically developing children (TDC). Twenty-four children with attention-deficit/hyperactivity disorder (ADHD), 21 with Tourette syndrome/tic disorder (TD), 21 with ADHD/TD comorbidity, and 22 TDC, matched for age and gender, underwent a two-night PSG, and their psychopathological scores and intelligence quotient (IQ) were assessed. Major PSG findings showed more REM sleep and shorter REM latency in the children with psychiatric disorders than in the TDC. Multiple regression analyses revealed that in groups with developmental psychopathology, REM sleep proportion correlated positively with scores of inattention and negatively with performance IQ. In contrast, in the group of TDC, REM sleep proportion correlated negatively with scores of inattention and positively with performance IQ. Whilst shorter REM latency was associated with greater inattention scores in children with psychopathology, no such an association existed in the group of TDC. Altogether, these results indicate an opposite impact of REM sleep on neurobehavioral functioning, related to presence or absence of developmental psychiatric disorders. Our findings suggest that during development, REM sleep functions may interact dissimilarly with different pathways of brain maturation.

Sleep disturbances in adolescents with ADHD: A systematic review and framework for future research

BACKGROUND

Biological mechanisms underlying symptom and prognostic heterogeneity in Attention-Deficit/Hyperactivity Disorder (ADHD) are unclear. Sleep impacts neurocognition and daytime functioning and is disrupted in ADHD, yet little is known about sleep in ADHD during adolescence, a period characterized by alterations in sleep, brain structure, and environmental demands as well as diverging ADHD trajectories.

METHODS

A systematic review identified studies published prior to August 2016 assessing sleep in adolescents (aged 10-19years) with ADHD or participating in population-based studies measuring ADHD symptoms.

RESULTS

Twenty-five studies were identified (19 subjective report, 6 using actigraphy/polysomnography). Findings are mixed but overall suggest associations between sleep disturbances and 1) ADHD symptoms in the population and 2) poorer clinical, neurocognitive, and functional outcomes among adolescents with ADHD. Common limitations of studies included small or non-representative samples, non-standardized sleep measures, and cross-sectional methodology.

CONCLUSIONS

Current data on sleep in adolescent ADHD are sparse and limited by methodological concerns. Future studies are critical for clarifying a potential role of sleep in contributing to heterogeneity of ADHD presentation and prognosis. Potential mechanisms by which sleep disturbances during adolescence may contribute to worsened symptom severity and persistence of ADHD into adulthood and an agenda to guide future research are discussed.

Sleep and mental disorders: A meta-analysis of polysomnographic research

Investigating sleep in mental disorders has the potential to reveal both disorder-specific and transdiagnostic psychophysiological mechanisms. This meta-analysis aimed at determining the polysomnographic (PSG) characteristics of several mental disorders. Relevant studies were searched through standard strategies. Controlled PSG studies evaluating sleep in affective, anxiety, eating, pervasive developmental, borderline and antisocial personality disorders, attention-deficit-hyperactivity disorder (ADHD), and schizophrenia were included. PSG variables of sleep continuity, depth, and architecture, as well as rapid-eye movement (REM) sleep were considered. Calculations were performed with the "Comprehensive Meta-Analysis" and "R" software. Using random effects modeling, for each disorder and each variable, a separate meta-analysis was conducted if at least 3 studies were available for calculation of effect sizes as standardized means (Hedges' g). Sources of variability, that is, sex, age, and mental disorders comorbidity, were evaluated in subgroup analyses. Sleep alterations were evidenced in all disorders, with the exception of ADHD and seasonal affective disorders. Sleep continuity problems were observed in most mental disorders. Sleep depth and REM pressure alterations were associated with affective, anxiety, autism and schizophrenia disorders. Comorbidity was associated with enhanced REM sleep pressure and more inhibition of sleep depth. No sleep parameter was exclusively altered in 1 condition; however, no 2 conditions shared the same PSG profile. Sleep continuity disturbances imply a transdiagnostic imbalance in the arousal system likely representing a basic dimension of mental health. Sleep depth and REM variables might play a key role in psychiatric comorbidity processes. Constellations of sleep alterations may define distinct disorders better than alterations in 1 single variable. (PsycINFO Database Record

Sleep Characteristics in Children with Attention Deficit Hyperactivity Disorder: Systematic Review and Meta-Analyses

STUDY OBJECTIVES

Sleep disturbances have been associated with attention deficit hyperactivity disorder (ADHD), but such relationship is still unclear. The results from the studies conducted do not provide enough evidence to support a sleep physiology inherent to ADHD. This study tries to determine if that sleep physiology really exists by comparing children with ADHD and control children in some sleep parameters.

METHODS

A search was conducted in several databases (Web of Science, Scopus, Pubmed and PsycINFO), and a manual search, to retrieve all the articles available from 1987 until March 2014. Of 8,678 non-duplicate studies retrieved, 11 studies met the inclusion and methodological quality criteria. Two meta-analyses were performed with eight of those studies, depending on data provided by them: polysomnographic or actigraphic. A fixed-effects model, and the standardized mean difference (SMD) as the index of effect size, were used in both meta-analyses.

RESULTS

Significant differences were found only in the meta-analysis with polysomnography as outcome. Children with ADHD were found to spend more time in stage 1 sleep than controls (pooled SMD = 0.32, 95% CI = 0.08-0.55, p value = 0.009).

CONCLUSIONS

Although few differences in sleep between children with ADHD and controls have been found in this review, further studies are required on this matter. Those studies should consider some variables discussed in this review, in order to obtain useful and reliable conclusions for research and clinical practice. Particularly, the influence of assessment criteria and ADHD subtypes in the sleep characteristics of children with ADHD should be addressed.

Sleep habits in children with attention-deficit/hyperactivity disorder predominantly inattentive type and associations with comorbid psychopathology symptoms

OBJECTIVES

Much of what is currently known about the sleep functioning of children with attention-deficit/hyperactivity disorder (ADHD) is based on samples of children with ADHD combined type, and no study to date has examined the association between sluggish cognitive tempo (SCT) and sleep functioning in children diagnosed with ADHD. Accordingly, the objectives of this study were to (1) describe the sleep habits of children diagnosed with ADHD predominantly inattentive type (ADHD-I) and (2) examine whether comorbid internalizing, oppositional, and/or SCT symptoms are associated with poorer sleep functioning in children with ADHD-I. This study extends the current literature by using a large, clinical sample of children with ADHD-I to examine the association between SCT and other psychopathology symptoms with children's sleep functioning.

METHODS

Participants included 147 children (age: 6-11, 59% male, 55% White) diagnosed with ADHD-I using a semi-structured diagnostic interview. Parents completed measures assessing their child's sleep habits as well as comorbid anxiety, depression, oppositionality, and SCT symptoms.

RESULTS

Fourteen percent of children with ADHD-I obtain less sleep than recommended and 31% have a sleep onset latency of greater than 20 minutes. The few children taking medication for ADHD had a longer sleep onset latency than those without medication. Twenty-seven percent of parents indicated that it is "difficult" to get their child out of bed on school days and 41% of parents indicated that their child needs to catch-up on sleep on the weekend "at least a little". Regression analyses found anxiety and SCT sleepy/tired symptoms to be the most consistent dimensions of psychopathology associated with sleep functioning, with little support for depression or oppositionality being associated with sleep.

CONCLUSIONS

A sizeable minority of children with ADHD-I experience impaired sleep. In addition to SCT sleepy/tired symptoms, comorbid anxiety was most consistently associated with poorer sleep functioning in children with ADHD-I. SCT daydreaming and working memory symptoms were unassociated with sleep functioning, and the size of the effects between SCT sleepy/tired and sleep functioning indicates that these are not overlapping constructs. Longitudinal studies are needed to evaluate the interrelations of sleep problems and comorbid psychopathology symptoms and their impact on the daytime functioning of children with ADHD-I.

Sleep in Autism Spectrum Disorder and Attention Deficit Hyperactivity Disorder

Sleep problems are common in autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). Sleep problems in these disorders may not only worsen daytime behaviors and core symptoms of ASD and ADHD but also contribute to parental stress levels. Therefore, the presence of sleep problems in ASD and ADHD requires prompt attention and management. This article is presented in 2 sections, one each for ASD and ADHD. First, a detailed literature review about the burden and prevalence of different types of sleep disorders is presented, followed by the pathophysiology and etiology of the sleep problems and evaluation and management of sleep disorders in ASD and ADHD.

In a randomized case-control trial with 10-years olds suffering from attention deficit/hyperactivity disorder (ADHD) sleep and psychological functioning improved during a 12-week sleep-training program

OBJECTIVES

We tested the hypothesis that sleep training would improve emotional, social and behavioural functioning in children with attention-deficit/hyperactivity disorder (ADHD) compared to children with ADHD without such intervention and to healthy controls.

METHODS

Forty children with ADHD were randomly assigned to intervention and control conditions. Parents of 20 children with ADHD were instructed and thoroughly supervised in improving their children's sleep schedules and sleep behaviour. Parents of the other 20 children with ADHD and parents of 20 healthy children received general information about sleep hygiene. At baseline and 12 weeks later, parents and children completed questionnaires related to children's sleep and psychological functioning.

RESULTS

Relative to the control groups, children in the intervention group improved sleep quantitatively and qualitatively (F values < 3.33, P values < 0.05). The intervention group children reported improvements in mood, emotions, and relationships (F values < 2.99, P values < 0.05). Parents reported that their children improved in physical and psychological wellbeing, mood, emotions, relationships, and social acceptance (F values < 3.02, P values < 0.05).

CONCLUSIONS

Training and monitoring parents of children with ADHD in regulating and supervising children's sleep schedules leads to positive changes in the emotions, behaviour and social lives of these children.

Sleep problems and their effect in ADHD

Sleep problems are common in attention-deficit/hyperactivity disorder (ADHD) to the extent that they mimic or exacerbate daytime symptoms expression. In this review, we advocate the need for a better understanding of sleep alterations in youths with ADHD and their impact on neurobehavioral functions including learning, memory and emotional regulation. An in-depth exploration of existing data showed that although extensively studied, the actual nature of sleep problems in ADHD and their effects on daytime behavior are still less well understood. Important issues, among which developmental changes in sleep architecture and role of subtle sleep electroencephalogram signatures, are generally neglected. Future research of sleep effects on behavior in ADHD would benefit from considering developmental aspects and links between brain activation patterns during sleep and wake.

Sleep and cognitive problems in patients with attention-deficit hyperactivity disorder

OBJECTIVES

Attention-deficit hyperactivity disorder (ADHD) is characterized by inattentive and impulsive behavior. Many ADHD patients reportedly have cognitive dysfunction and sleep problems, including longer sleep latency, lower sleep efficiency, and shorter total sleep time. The purpose of this study was to examine neurocognitive functions and nocturnal sleep parameters in patients with ADHD, using a cognitive function test and actigraphy.

METHODS

Subjects included 37 male patients with ADHD and 32 controls (7-12 years of age). For each participant, we determined intelligence quotient (IQ) and administered the Matching Familiar Figures Test (MFFT) and 72-hour actigraphy. The relationships between sleep parameters and cognitive functions were assessed.

RESULTS

ADHD patients significantly differed from controls in several cognitive functions and sleep variables. In the MFFT, response error rate (P<0.001) and error counts (P=0.003) were significantly increased in ADHD patients compared with control children. MFFT response latency was significantly shorter in ADHD patients than in controls (P<0.001). In addition, sleep latency (P=0.01), wake after sleep onset (WASO) (P<0.001), and fragmentation index (P<0.001) were evaluated by actigraphy and found to be significantly increased in patients with ADHD compared with controls. However, no significant differences in total sleep time or sleep efficiency were observed. WASO and response error rates were positively correlated in patients with ADHD (rho =0.52, P=0.012). Furthermore, fragmentation index sleep variables were significantly positively correlated with response error (rho =0.44, P=0.008) and response latency rates (rho =0.4, P=0.018) in the MFFT. Reaction error rate was significantly associated with the fragmentation index (beta =0.94, P=0.024).

CONCLUSION

Patients with ADHD had more sleep problems, including significantly increased sleep latency, WASO, and fragmentation index, and poorer cognitive function, compared with controls. Some of these sleep problems, including WASO and the fragmentation index, were positively correlated with impulsivity, illustrated by the cognitive function tests in patients with ADHD. However, further studies with large sample sizes and the addition of polysomnography and determination of ADHD subtypes should be performed to confirm our results regarding sleep and cognitive problems in patients with ADHD.

Attention-deficit/hyperactivity disorder (ADHD) and adaptation night as determinants of sleep patterns in children

Sleep problems are a prominent feature in children with attention-deficit/hyperactivity disorder (ADHD) but their relationships to sleep structure are not consistent across studies. We aimed at further examining the sleep architecture in children with ADHD, while considering the role of the first-night effect (FNE) as a possible confounder. Twenty unmedicated children with ADHD combined type (8-15 years old; mean 11.24, SD 2.31) and 19 healthy controls, matched for age and gender, underwent polysomnography during an adaptation and a consecutive second night. ADHD and controls displayed a typical FNE without group differences. Independently of testing night, children with ADHD spent more time in sleep and had shortened rapid eye movement (REM) sleep latency and a greater amount of REM sleep relative to controls. However, the increased REM sleep amount in ADHD children was more expressed in the second night when it was also significantly related to scores of inattention and hyperactivity. Our results (1) document similar sleep adaptation processes in children with ADHD and typically developing children, (2) reveal that REM sleep changes in association with ADHD-specific psychopathology may characterize sleep in ADHD children, which is evident only when the FNE is accounted for, (3) indicate that ADHD psychopathology and adaptation night may exert opposite effects on REM sleep in children. These results may prompt the awareness of clinicians about the importance of actual sleep alterations and their precise evaluation in children with ADHD, which could significantly contribute to better diagnostic, treatment and early prevention strategies.

A pathophysiologic approach to growth problems in children with attention-deficit/hyperactivity disorder

In recent years there has been an increasing trend in the diagnosis and treatment of children with attention-deficit/hyperactivity disorder (ADHD) worldwide. One of the most frequently discussed side effects of these treatments is related to problems of growth. In order to better understand what ADHD is and the mechanisms by which it could affect growth, this article reviews relevant data from a clinical and neurophysiologic perspective to improve understanding of this controversial issue.

Sleep disturbances in children with attention-deficit/hyperactivity disorder

In this article, we advocate the need for better understanding and treatment of children exhibiting inattentive, hyperactive, impulsive behaviors, by in-depth questioning on sleepiness, sleep-disordered breathing or problematic behaviors at bedtime, during the night and upon awakening, as well as night-to-night sleep duration variability. The relationships between sleep and attention-deficit/hyperactivity disorder (ADHD) are complex and are routinely overlooked by practitioners. Motricity and somnolence, the most consistent complaints and objectively measured sleep problems in children with ADHD, may develop as a consequence of multidirectional and multifactorial pathways. Therefore, subjectively perceived or reported restless sleep should be evaluated with specific attention to restless legs syndrome or periodic limb movement disorder, and awakenings should be queried with regard to parasomnias, dyssomnias and sleep-disordered breathing. Sleep hygiene logs detailing sleep onset and offset quantitatively, as well as qualitatively, are required. More studies in children with ADHD are needed to reveal the 24-h phenotype, or its sleep comorbidities.

Sleep in attention-deficit/hyperactivity disorder in children and adults: past, present, and future

The understanding that sleep can give rise to, or exacerbate symptoms of attention-deficit/hyperactivity disorder (ADHD), and that good sleep hygiene improves attention and concentration tasks has sparked interest in the investigation of possible etiological relationships between sleep disorders and ADHD. Studies indicate that 30% of children and 60-80% of adults with ADHD have symptoms of sleep disorders such as daytime sleepiness, insomnia, delayed sleep phase syndrome, fractured sleep, restless legs syndrome, and sleep disordered breathing. The range and diversity of findings by different researchers have posed challenges in establishing whether sleep disturbances are intrinsic to ADHD or whether disturbances occur due to co-morbid sleep disorders. As a result, understanding of the nature of the relationship between sleep disturbances/disorders and ADHD remains unclear. In this review, we present a comprehensive and critical account of the research that has been carried out to investigate the association between sleep and ADHD, as well as discuss mechanisms that have been proposed to account for the elusive relationship between sleep disturbances, sleep disorders, and ADHD.

Comorbidity and confounding factors in attention-deficit/hyperactivity disorder and sleep disorders in children

Sleep problems are commonly reported in children with attention-deficit/hyperactivity disorder (ADHD) symptoms. Research data regarding the complex and reciprocal relationship between ADHD and sleep disturbances has now accumulated. This paper is focused on the types of sleep problems that are associated with ADHD symptomatology, and attempts to untangle confounding factors and overlapping symptoms. The goal is also to present an updated overview of the pathophysiology of and treatment strategies for sleep problems in children with ADHD. The review also points out that future research will be needed to clarify further the other psychiatric comorbidities and side effects of medication in order to improve treatment outcomes and prevent misdiagnosis in clinical practice.

Ciclo vigília/sono e o transtorno de déficit de atenção/hiperatividade

OBJETIVO: Analisar as relações entre ciclo vigília/sono e transtorno de déficit de atenção/hiperatividade. FONTES DE DADOS: Os artigos foram selecionados nas bases de dados SciELO e PubMed, utilizando-se "sono", "transtorno de déficit de atenção/hiperatividade", "atividade motora" e "crianças" como palavras-chave para a busca. SÍNTESE DOS DADOS: Embora os resultados de diferentes estudos sejam inconclusivos e, por vezes, contraditórios, não sendo possível estabelecer relações claras entre sono e transtorno do déficit de atenção/hiperatividade, observa-se que o sono das crianças diagnosticadas difere do sono de crianças que não possuem o transtorno, sugerindo que alterações de sono possam se relacionar ao transtorno do déficit de atenção/hiperatividade. CONCLUSÕES: A falta de marcadores biológicos e de conhecimento a respeito da sua etiologia gera dificuldades na determinação da real prevalência do transtorno do déficit de atenção/hiperatividade, além de limitar sua compreensão e a busca por novas formas de tratamento e prevenção. Embora dificuldades de sono sejam frequentemente relatadas na prática clínica e já tenham sido utilizadas como um dos critérios diagnósticos para o transtorno, pouco se sabe sobre a possível participação da privação de sono na etiologia do transtorno do déficit de atenção/hiperatividade.

Sleep and its importance in adolescence and in common adolescent somatic and psychiatric conditions

Restoring sleep is strongly associated with a better physical, cognitive, and psychological well-being. By contrast, poor or disordered sleep is related to impairment of cognitive and psychological functioning and worsened physical health. These associations are well documented not only in adults but also in children and adolescents. Importantly, adolescence is hallmarked by dramatic maturational changes in sleep and its neurobiological regulation, hormonal status, and many psychosocial and physical processes. Thus, the role of sleep in mental and physical health during adolescence and in adolescent patients is complex. However, it has so far received little attention. This review first presents contemporary views about the complex neurobiology of sleep and its functions with important implications for adolescence. Second, existing complex relationships between common adolescent somatic/organic, sleep-related, and psychiatric disorders and certain sleep alterations are discussed. It is concluded that poor or altered sleep in adolescent patients may trigger and maintain many psychiatric and physical disorders or combinations of these conditions, which presumably hinder recovery and may cross into later stages of life. Therefore, timely diagnosis and management of sleep problems appear critical for growth and development in adolescent patients.

Normative values of polysomnographic parameters in childhood and adolescence: quantitative sleep parameters

OBJECTIVE

To provide normative values for sleep macroarchitecture of healthy children aged 1-18 years using the AASM sleep scoring criteria, assessing the effects of gender, age, and Tanner pubertal stage.

METHODS

One-night polysomnography was performed at subjects' habitual bedtimes in 16 laboratories on 209 healthy German children.

RESULTS

Normal values of sleep macrostructure show significant age dependencies (p<0.05). Increasing with age: awakening index, R latency (RL), sleep efficiency (SE) (total sleep time (TST)/sleep period time (SPT)) and SE (TST/time in bed), stage N2, mean sleep cycle duration, number of stage shifts. Decreasing with age: TST, SPT, wake after sleep onset, stage N3, stage R, movement time (MT), number of sleep cycles. The following sleep parameters show a dependency on Tanner stages as well as corresponding age (p<0.05):TST, SPT, awakening index, R latency, stage N2, stage N3, MT, number of sleep cycles, mean sleep cycle duration. No gender dependencies were found.

CONCLUSION

The given study, considering AASM rules, shows the development of sleep in normal children ages 1-18. Subject selection criteria and other factors influencing sleep as well AASM guideline modifications including scoring arousals in N2 and scoring MT as a measure of sleep fragmentation are discussed.

Hyperactive-impulsive symptoms associated with self-reported sleep quality in nonmedicated adults with ADHD

OBJECTIVE

Individuals with ADHD often report sleep problems. Though most studies on ADHD and sleep examined children or nonclinically diagnosed adults, the present study specifically examines nonmedicated adults with ADHD to determine whether inattentive and hyperactive-impulsive symptoms are associated with sleep problems.

METHOD

A total of 22 nonmedicated adults diagnosed with ADHD are assessed with a DSM-IV-based interview and the Pittsburg Sleep Quality Index (PSQI).

RESULTS

The number of hyperactive-impulsive symptoms indicate a positive correlation with sleep duration, habitual sleep efficiency, and global PSQI score. No significant associations are found between inattentive symptoms and sleep quality.

CONCLUSION

The results show that sleep problems are associated with hyperactive and impulsive symptoms in nonmedicated adults with ADHD. These findings provide information on the nature of sleep problems without the confounding effects of medication associated with ADHD. Treatment of sleep problems, especially in those with hyperactive-impulsive symptoms, may help ameliorate ADHD symptomatology.

Eye movement during REM sleep in children with attention deficit hyperactivity disorder

The current study examined eye movements during rapid eye movement (REM) sleep of children ages 6-10 with attention deficit hyperactivity disorder (ADHD) and a control group without any known medical or psychiatric diagnoses. Electro-ocular recordings from archived polysomnograms were evaluated. An in-depth analysis revealed significantly lower frequency, higher amplitude eye movement in those with ADHD (N = 13) compared to the control group (N = 16). Although the results of this study are novel, defining distinct differences in eye movement during REM sleep of children with ADHD has the potential to supplement current biopsychosocial diagnostic models and further the understanding of the neurodevelopmental basis of ADHD.

Attention-deficit/hyperactivity disorder and sleep disorders in children

Attention-deficit/hyperactivity disorder (ADHD) is a neurocognitive and behavior abnormality commonly seen in childhood and adolescence. Symptoms and consequences of ADHD and sleep problems frequently overlap, and their relationship is complex and bidirectional. To avoid inappropriate diagnosis and inadequate management, mental health professionals should assess sleep problems and disorders in children, adolescents, and adults with ADHD-related symptoms and in those with a diagnosis of ADHD. Screening for other psychiatric comorbidities and the side effects of medications, such as psychostimulants, is necessary when considering sleep complaints, because both have adverse effects on sleep.

Cognitive and electroencephalographic disturbances in children with attention-deficit/hyperactivity disorder and sleep problems: new insights

There is overlap between the behavioural symptoms and disturbances associated with Attention-Deficit/Hyperactivity Disorder (AD/HD) and sleep problems. The aim of this study was to examine the extent of overlap in cognitive and electrophysiological disturbances identified in children experiencing sleep problems and children with AD/HD or both. Four groups (aged 7-18) were compared: children with combined AD/HD and sleep problems (n=32), children with AD/HD (n=52) or sleep problems (n=36) only, and children with neither disorder (n=119). Electrophysiological and cognitive function measures included: absolute EEG power during eyes open and eyes closed, event-related potential (ERP) components indexing attention and working memory processes (P3), and a number of standard neuropsychological tests. Children with symptoms of both AD/HD and sleep problems had a different profile from those of children with either AD/HD or sleep problems only. These findings suggest it is unlikely that disturbances in brain and cognitive functioning associated with sleep problems also give rise to AD/HD symptomatology and consequent diagnosis. Furthermore, findings suggest that children with symptoms of both AD/HD and sleep problems may have a different underlying aetiology than children with AD/HD-only or sleep problems-only, perhaps requiring unique treatment interventions.

The Role of Sleep in Childhood Psychiatric Disorders

Although sleep problems often comprise core features of psychiatric disorders, inadequate attention has been paid to the complex, reciprocal relationships involved in the early regulation of sleep, emotion, and behavior. In this paper, we review the pediatric literature examining sleep in children with primary psychiatric disorders as well as evidence for the role of early sleep problems as a risk factor for the development of psychopathology. Based on these cumulative data, possible mechanisms and implications of early sleep disruption are considered. Finally, assessment recommendations for mental health clinicians working with children and adolescents are provided toward reducing the risk of and improving treatments for sleep disorders and psychopathology in children and adolescents.

Sleep characteristics of children and adolescents with attention deficit-hyperactivity disorder

This article reviews sleep characteristics of children and adolescents who have attention-deficit/hyperactivity disorder (ADHD). Research on sleep disturbances in individuals who have ADHD without comorbid conditions, measured both objectively and subjectively, is first presented. The impact of primary sleep disorders associated with ADHD is then discussed. The effects of psychiatric comorbidities on the sleep patterns of children and adolescents who have ADHD are then reviewed, and sleep alterations associated with medications used to treat ADHD and comorbid conditions are addressed.

Sleep in children with attention-deficit/hyperactivity disorder: meta-analysis of subjective and objective studies

OBJECTIVE

To perform a meta-analysis of subjective (i.e., based on questionnaires) and objective (i.e., using polysomnography or actigraphy) studies comparing sleep in children with attention-deficit/hyperactivity disorder (ADHD) versus controls.

METHOD

We searched for subjective and objective sleep studies (1987-2008) in children with ADHD (diagnosed according to standardized criteria). Studies including subjects pharmacologically treated or with comorbid anxiety/depressive disorders were excluded.

RESULTS

Sixteen studies, providing 9 subjective and 15 objective parameters and including a total pooled sample of 722 children with ADHD versus 638 controls, were retained. With regard to subjective items, the meta-analysis indicated that children with ADHD had significantly higher bedtime resistance (z = 6.94, p <.001), more sleep onset difficulties (z = 9.38, p <.001), night awakenings (z = 2.15, p =.031), difficulties with morning awakenings (z = 5.19, p <.001), sleep disordered breathing (z = 2.05, p =.040), and daytime sleepiness (z = 1.96, p =.050) compared with the controls. As for objective parameters, sleep onset latency (on actigraphy), the number of stage shifts/hour sleep, and the apnea-hypopnea index were significantly higher in the children with ADHD compared with the controls (z = 3.44, p =.001; z = 2.43, p =.015; z = 3.47, p =.001, respectively). The children with ADHD also had significantly lower sleep efficiency on polysomnography (z = 2.26, p =.024), true sleep time on actigraphy (z = 2.85, p =.004), and average times to fall asleep for the Multiple Sleep Latency Test (z = 6.37, p <.001) than the controls.

CONCLUSIONS

The children with ADHD are significantly more impaired than the controls in most of the subjective and some of the objective sleep measures. These results lay the groundwork for future evidence-based guidelines on the management of sleep disturbances in children with ADHD.

Sleep disturbances in prepubertal children with attention deficit hyperactivity disorder: a home polysomnography study

STUDY OBJECTIVE

To examine sleep architecture and reported sleep problems in children with ADHD and normal controls, while considering the roles of pertinent moderating factors.

DESIGN

Overnight sleep recordings were conducted in 15 children diagnosed with ADHD (DSM-IV) without comorbid psychiatric problems and in 23 healthy controls aged 7 to 11 years. Children were on no medication, in good health and did not consume products containing caffeine > or = 7 days prior to the polysomnography (PSG) study. PSG evaluation was performed at each child's home; children slept in their regular beds and went to bed at their habitual bedtimes.

MEASUREMENTS

Standard overnight multichannel PSG evaluation was performed using a portable polysomnography device. In addition, parents were asked to complete a sleep questionnaire.

RESULTS

Compared to controls, children in the ADHD group had significantly shorter duration of REM sleep, smaller percentage of total sleep time spent in REM sleep, and shorter sleep duration. In addition, the ADHD group had higher scores on the insufficient sleep and sleep anxiety factors than children in the control group.

CONCLUSION

The present findings support the hypothesis that children with ADHD present sleep disturbances.

Sleep study abnormalities in children with attention deficit hyperactivity disorder

The study objective was to describe polysomnographic findings in children with attention deficit hyperactivity disorder (ADHD) with diverse sleep problems. Polysomnographic data were retrospectively analyzed for 33 children (age 3-16 years) with ADHD who had sleep studies performed for diverse sleep complaints. Eight patients (24%) had obstructive sleep apnea, 10 (30%) had periodic limb movements of sleep, 8 (24%) had upper airway resistance syndrome, and 5 (15%) had obstructive hypoventilation. The ADHD group showed decreased sleep efficiency, increased arousal index, increased wake after sleep onset, decreased oxygen saturation nadir, and increased snoring, compared with control subjects. Compared with ADHD children without sleep disordered breathing, those who had sleep disordered breathing were significantly more obese and had more sleep architectural abnormalities (including increased sleep latency, increased rapid eye movement latency, increased wake after sleep onset, and increased arousal index with more oxygen desaturations), although total sleep time and sleep efficiency were not significantly different. Sleep disordered breathing and periodic limb movements of sleep appear to be common among children with ADHD who have symptoms of disturbed sleep.

Rapid eye movement latency in children and adolescents

Rapid eye movement sleep distribution changes during development, but little is known about rapid eye movement latency variation in childhood by age, sex, or pathologic sleep states. We hypothesized that: (1) rapid eye movement latency would differ in normal children by age, with a younger cohort (1-10 years) demonstrating shorter rapid eye movement latency than an older group (>10-18 years); (2) rapid eye movement latency in children would differ from typical adult rapid eye movement latency; and (3) intrinsic sleep disorders (narcolepsy, pediatric obstructive sleep apnea syndrome) would disrupt normal developmental patterns of rapid eye movement latency. A retrospective chart review included data from clinic visits and of rapid eye movement latency and other parameters measured by overnight polysomnography. Participants included 98 control children, 90 children with obstructive sleep apnea syndrome, and 13 children with narcolepsy. There were no statistically significant main effects of age category or sex on rapid eye movement latency. Rapid eye movement latency, however, exhibited a significant inverse correlation with age within the older control children. Healthy children exhibited rapid eye movement latencies significantly longer than adults. Normal control patients demonstrated significantly longer rapid eye movement latency than obstructive sleep apnea syndrome and narcolepsy patients.

ADHD subtypes and comorbid anxiety, depression, and oppositional-defiant disorder: differences in sleep problems

OBJECTIVE

Sleep problems were analyzed in children with ADHD (Attention-deficit hyperactivity disorder).

METHODS

Scales were completed by parents of 135 control children and 681 children with ADHD combined type (ADHD-C) or inattentive type (ADHD-I) with or without comorbid oppositional defiant disorder (ODD), anxiety, or depression.

RESULTS

Children with ADHD-I alone had the fewest sleep problems and did not differ from controls. Children with ADHD-C had more sleep problems than controls and children with ADHD-I. Comorbid anxiety/depression increased sleep problems, whereas ODD did not. Daytime sleepiness was greatest in ADHD-I and was associated with sleeping more (not less) than normal. Medicated children had greater difficulty falling asleep than unmedicated children.

CONCLUSIONS

Differences in sleep problems were found as a function of ADHD subtype, comorbidity, and medication.

Nonsignificance of sleep relative to IQ and neuropsychological scores in predicting academic achievement

OBJECTIVE

The goal of the study was to determine the relative importance of sleep, IQ, neuropsychological, and attention-deficit/hyperactivity disorder (ADHD) scores in predicting academic achievement.

METHOD

Objective overnight polysomnograph sleep scores, parent ratings of sleep problems, IQ, neuropsychological test scores, and parent ratings of ADHD were used to predict academic achievement in a general population sample of 412 elementary schoolchildren, 6 to 12 years of age with IQs of 71 to 147.

RESULTS

Using stepwise linear regression analysis, IQ was the best single predictor of reading and math achievement test scores. The most powerful combined predictors of achievement were IQ and some of the neuropsychological test scores. Subjective parent-reported sleep problems and objective polysomnograph scores (apnea-hypopnea index, mean oxygen saturation and lowest saturation percentage during sleep, snoring frequency and severity, sleep latency, minutes to rapid eye movement (REM) sleep, arousal index, number of awakenings, sleep efficiency, and percentage of stage 1, 2, 3, 4, and REM sleep) did not contribute significantly more to the prediction of achievement. Children with and without sleep problems did not differ from each other in achievement. IQ, neuropsychological test scores, and ADHD ratings were all significantly related to achievement, but correlations between achievement and objective and subjective sleep scores were all nonsignificant.

CONCLUSIONS

There may be individual children for whom sleep problems affect achievement, but for a large group of community children, sleep was not significantly related to academic functioning. In contrast, IQ and neuropsychological test scores were powerful predictors of achievement.

Comorbidity of tic disorders & ADHD: conceptual and methodological considerations

BACKGROUND

The causes and pathophysiological mechanisms of the common comorbidity of tic disorders and Attention-deficit/Hyperactivity disorder (TD + ADHD; about 50% of TD, about 20% of ADHD) still remain unclear. Studies with a 2 x 2 design comparing groups of children with TD, ADHD, TD + ADHD and healthy controls are in need and may disentangle the influences of TD versus ADHD in the case of comorbidity. Unfortunately, conceptual and methodological problems can restrain possible conclusions from these studies.

METHOD

A review of the literature on artifactual and non-artifactual models of comorbidity in general and specially for TD + ADHD was conducted.

RESULTS

The first section describes various possible models of comorbidity and their corresponding hypotheses concerning expected patterns of findings comparing groups of children with TD, ADHD, TD + ADHD and healthy controls. In the second part research results concerning psychopathological, neuropsychological, neurophysiological, structural and functional imaging, as well as genetic characteristics are summarized. In the third section possible conclusions and their limitations due to conceptual and methodological problems possibly contributing to the ambiguous results are discussed. Finally, future research strategies and the need for full causal models are outlined.

CONCLUSION

Some components of the etiological pathways of TD + ADHD may well be shared with the 'pure' conditions while others may be unique.