The circadian rhythm in adult attention-deficit/hyperactivity disorder: current state of affairs

Classification and Epidemiology of Sleep Disorders in Children and Adolescents

Sleep disturbances are common in children and adolescents but still remain unrecognized and undertreated. Several classification systems of sleep disorders are available, which include recent attempts to develop more specific nosologic categories that reflect developmental aspects of sleep. The prevalence of sleep disorders has been studied across various samples of healthy, typically developing children and those with special medical, psychiatric, and neurodevelopmental needs. Sleep disorders are highly prevalent in children and adolescents with psychiatric disorders, making it important for mental health professionals to be aware of sleep problems and to address them in the context of psychiatric comorbidities.

Armodafinil as a Potential Pharmacological Treatment for Attention Deficit Hyperactivity Disorder in Adults: A Review

INTRODUCTION

Armodafinil is a psychostimulant that promotes alertness, and it has been shown to improve attention, memory, and fatigue in healthy adults and adults with neurodevelopmental conditions that share symptoms with Attention Deficit Hyperactivity Disorder (ADHD). It is generally well tolerated and safe, and most of the adverse events reported are considered not serious. However, the available evidence on the efficacy of armodafinil for the treatment of ADHD in adults is scarce.

OBJECTIVE

The present review aims to perform a systematized search of the available evidence on the possible therapeutic benefit of armodafinil treatment in adult patients with ADHD.

METHODS

A literature review using PubMed was conducted to compile and summarize the available clinical and scientific evidence on the possible use of armodafinil as a pharmacological treatment in adult patients with ADHD.

RESULTS

From the 86 articles reviewed, the available evidence showed that both acute and chronic treatment with armodafinil can improve wakefulness, memory, impulse control, and executive functions in adults with sleep disorders and other conditions. In addition, evidence of improvement in cognitive functions and mood alterations in other neuropsychiatric conditions was shown.

CONCLUSION

Armodafinil could be useful for the treatment of ADHD in adults, according to the review of the literature from both pre-clinical and clinical 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.

Analyzing sleep status in children with acute leukemia

BACKGROUND

Quality sleep is essential for physical and mental health. We aimed to analyze sleep disorders in children with acute leukemia and explore associated factors.

METHODS

General data and sleep disorders in children with acute leukemia during chemotherapy were collected by general questionnaires, Children's Sleep Disorders Scale and the Parenting Stress Index-short form.

RESULTS

In total, 173 valid questionnaires were collected. The total Sleep Disorder Scale score > 39 is considered a sleep disorder, while sleep disorders accounted for 45.66% (79/173). In the cohort, 167 children had acute lymphoblastic leukemia, with 40.12% (67/167) having sleep disorders, while six children had acute non-lymphoblastic leukemia, with 50.00% (3/6) having sleep disorders. Single- and multi-factor regression analyses of age, gender, number of children in the family, and time spent using electronic devices showed that factors influencing sleep disorders in these children were mainly parental scolding and adenoid hypertrophy. Children with sleep disorders had more parental stress than those without sleep disorders (P < 0.05).

CONCLUSIONS

The high incidence of sleep disorders in children with acute leukemia is related to airway conditions and parental behaviors. Sleep disorders in children can increase parenting stress. Factors potentially affecting sleep quality should be addressed as early as possible, while parental education should be strengthened to better facilitate the physical and psychological recovery of their children.

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.

Circadian Effects on Attention and Working Memory in College Students With Attention Deficit and Hyperactivity Symptoms

Objective

Individuals with an evening chronotype prefer to sleep later at night, wake up later in the day and perform best later in the day as compared to individuals with morning chronotype. Thus, college students without ADHD symptoms with evening chronotypes show reduced cognitive performance in the morning relative to nighttime (i.e., desynchrony effect). In combination with symptoms presented in attention deficit hyperactivity disorder (ADHD), we predicted that having evening chronotype renders impairment in attention during the morning, when students require optimal performance, amplifying desynchrony.

Method

Four hundred college students were surveyed for evening chronotype and symptoms of ADHD. Of those surveyed, 43 students with evening chronotype (19 with ADHD symptoms) performed laboratory attention tasks and were queried about fatigue during morning and evening sessions.

Results

Students with ADHD symptoms demonstrated a greater decrement in sustained attentional vigilance when abstaining from stimulants and asked to perform cognitive tests at times misaligned with natural circadian rhythms in arousal compared to their non-ADHD counterparts with the same chronotype. While individuals with ADHD symptoms had slower reaction-times during sustained attention tasks in the morning session compared to those without symptoms, there was no significant group difference in working memory performance, even though both groups made more errors in the morning session compared to the evening session.

Conclusion

These findings suggest that evening chronotype students with ADHD symptoms are at a greater disadvantage when having to perform sustained attention tasks at times that are not aligned to their circadian rhythm compared to their neuro-typical peers. The implications of this finding may be useful for the provision of disability accommodations to college age students with ADHD when they are expected to perform tasks requiring sustained attention at times misaligned with their circadian rhythms.

Adult ADHD and sleep disorders: Prevalence, severity and predictors of sleep disorders in a sample of Italian psychiatric outpatients

OBJECTIVE

Sleep disorders are frequent in adult subjects diagnosed with ADHD. The aims of the present study were to assess the prevalence and the severity of sleep disorders in a sample of Italian psychiatric outpatients, to compare the prevalence and severity of sleep disorders in patients with and without diagnosis of adult ADHD, and to evaluate the role of ADHD as an individual predictor of sleep disturbances severity.

METHOD

634 outpatients accessing psychiatric services were assessed with the Mini-International Neuropsychiatric Interview (MINI) Plus V. 5.0.0 interview and the Adult ADHD self-report Scale Symptoms Checklist (ASRS)-V 1.1 Short Form. Patients positive to the ASRS-V 1.1 were assessed with the Diagnostic Interview for ADHD in Adults (DIVA) 2.0. Sleep disorders and sleep disturbances' severity were assessed with the PROMIS Adult Sleep Disturbance Scale.

RESULTS

Sleep disorders were more frequent (p < 0.001) and sleep disturbances were more severe (d = 1.26, p < 0.001) in subjects diagnosed with adult ADHD compared to other outpatients. Among the 44 subjects diagnosed with ADHD, 15 (34.1%) reported no or slight sleep disturbances, 9 (20.5%) a mild sleep disorder, 17 (38.6%) a moderate sleep disorder and 3 (6.8%) a severe sleep disorder. ADHD diagnosis, multiple psychiatric comorbidity and history of suicide attempts emerged as individual predictors of worse sleep disturbances.

CONCLUSION

Sleep disorders are more frequent and severe in subjects diagnosed with ADHD compared to other adult outpatients. Sleep disturbances might represent an intrinsic feature in adult ADHD subjects, presenting important clinical repercussions, and should be routinely evaluated and monitored in this population.

The impact of insomnia disorder on adult attention-deficit/hyperactivity disorder severity: A six-month follow-up study

BACKGROUND AND OBJECTIVES

The longitudinal relationship between insomnia disorder and adult attention-deficit/hyperactivity disorder (ADHD) has been scarcely investigated. This study aimed to evaluate the relationship between the remission of insomnia disorder and adult ADHD clinical severity, psychiatric and medical comorbidities, and the health-related quality of life (HRQoL) in a 6-month follow-up.

METHODS

Ninety-two adult patients with ADHD and insomnia disorder (52.2% males; mean age 39.5 ± 11.0 years) were comprehensively assessed at baseline, 3 months, and 6 months of a follow-up period. The evaluation included semi-structured interviews (for ADHD and comorbidity assessment), the Pittsburgh Sleep Quality Index, Insomnia Severity Index, and Epworth Sleepiness Scale. The diagnosis of ADHD and insomnia disorder was performed according to DSM-5 criteria. At baseline and follow-up, psychoeducation/sleep hygiene and, if necessary, pharmacological were prescribed for insomnia.

RESULTS

Eighty-seven patients completed the 6-month follow-up. Insomnia disorder remission was reported in 72.4% of cases and was related to a greater improvement in ADHD symptoms and severity throughout the follow-up period. Additionally, an improvement in psychiatric comorbidities and better HRQoL were associated with insomnia disorder remission.

CONCLUSION

The current study highlights that the treatment of insomnia disorder in ADHD adult patients may have an important role in the outcome of ADHD therapeutic approaches by reducing their severity.

Animal Models of ADHD?

To describe animals that express abnormal behaviors as a model of Attention-Deficit Hyperactivity Disorder (ADHD) implies that the abnormalities are analogous to those expressed by ADHD patients. The diagnostic features of ADHD comprise inattentiveness, impulsivity, and hyperactivity and so these behaviors are fundamental for validation of any animal model of this disorder. Several experimental interventions such as neurotoxic lesion of neonatal rats with 6-hydroxydopamine (6-OHDA), genetic alterations, or selective inbreeding of rodents have produced animals that express each of these impairments to some extent. This article appraises the validity of claims that these procedures have produced a model of ADHD, which is essential if they are to be used to investigate the underlying cause(s) of ADHD and its abnormal neurobiology.

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.

Sleep disorders in attention-deficit hyperactivity disorder and autism spectrum disorder: a pragmatic approach to assessment and management

Sleep is essential for survival and humans spend approximately one-third of their life asleep. Adequate sleep is needed to maintain both physical and psychological health. Routinely getting less than the recommended amount of sleep for your age can have profound negative effects on health, such as increasing the likeliness of psychiatric illness, diabetes, cardiovascular disease and stroke. In children and adults with neurodevelopmental disorders, the prevalence of sleep disorders is significantly higher than in the general population. Given the relationship between sleep and psychiatric disorders, it is essential that psychiatrists have knowledge of the principles of sleep medicine. In this article, we focus on the common sleep disorders found in those with attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) and give an overview of screening, diagnosis and management.

The efficacy of mindfulness-based interventions in attention-deficit/hyperactivity disorder beyond core symptoms: A systematic review, meta-analysis, and meta-regression

BACKGROUND

Mindfulness-Based Interventions (MBIs) have been increasingly proposed as treatment in patients with Attention-Deficit/Hyperactivity Disorder (ADHD), showing promising results on different proposed outcomes, in both children and adults.

OBJECTIVES

To systematically review and meta-analyse studies concerning the effects of MBIs on either ADHD and associated features, associated clinical conditions, neurocognitive impairments, mindfulness skills, global functioning and quality of life.

METHODS

Searches were conducted on five databases, including controlled and observational studies on both adults and children populations. The review process was compliant to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Meta-analyses and meta-regression models were conducted.

RESULTS

Thirty-one full-texts were included. In both adults and children, MBIs showed to be more effective than waiting lists in improving ADHD symptoms and some other outcomes. In adults, a medium pooled effect size was shown by meta-analysis for ADHD symptoms but in some cases a publication bias was detected. Subgroup analysis and meta-regression confirmed the gap detected by our systematic review between the medium/large effect size of inactive-controlled studies and the low/negligible one of active-controlled studies. In children, no active-controlled studies have been conducted. Mindfulness Awareness Practice (MAP) and Mindfulness Based Cognitive Therapy (MBCT) were the most used protocols in adult studies, whereas a combination of MBCT and Mindfulness Based Stress Reduction (MBSR) was more preferred for children and adolescent patients.

CONCLUSIONS

Even if further studies with a better methodology are needed, we can suggest the MBIs may be useful as complementation and not as replacement of other active interventions.

The Habenula in the Link Between ADHD and Mood Disorder

Attention-deficit/hyperactivity disorder (ADHD) is a childhood-onset, neurodevelopmental disorder, whereas major depressive disorder (MDD) is a mood disorder that typically emerges in adulthood. Accumulating evidence suggests that these seemingly unrelated psychiatric disorders, whose symptoms even appear antithetical [e.g., psychomotor retardation in depression vs. hyperactivity (psychomotor acceleration) in ADHD], are in fact associated with each other. Thus, individuals with ADHD exhibit high comorbidity with MDD later in life. Moreover, genetic studies have shown substantial overlaps of susceptibility genes between ADHD and MDD. Here, we propose a novel and testable hypothesis that the habenula, the epithalamic brain region important for the regulation of monoamine transmission, may be involved in both ADHD and MDD. The hypothesis suggests that an initially hypoactive habenula during childhood in individuals with ADHD may undergo compensatory changes during development, priming the habenula to be hyperactive in response to stress exposure and thereby increasing vulnerability to MDD in adulthood. Moreover, we propose a new perspective on habenular deficits in psychiatric disorders that consider the habenula a neural substrate that could explain multiple psychiatric disorders.

Evolutionary conservations, changes of circadian rhythms and their effect on circadian disturbances and therapeutic approaches

The circadian rhythm is essential for the interaction of all living organisms with their environments. Several processes, such as thermoregulation, metabolism, cognition and memory, are regulated by the internal clock. Disturbances in the circadian rhythm have been shown to lead to the development of neuropsychiatric disorders, including attention-deficit hyperactivity disorder (ADHD). Interestingly, the mechanism of the circadian rhythms has been conserved in many different species, and misalignment between circadian rhythms and the environment results in evolutionary regression and lifespan reduction. This review summarises the conserved mechanism of the internal clock and its major interspecies differences. In addition, it focuses on effects the circadian rhythm disturbances, especially in cases of ADHD, and describes the possibility of recombinant proteins generated by eukaryotic expression systems as therapeutic agents as well as CRISPR/Cas9 technology as a potential tool for research and therapy. The aim is to give an overview about the evolutionary conserved mechanism as well as the changes of the circadian clock. Furthermore, current knowledge about circadian rhythm disturbances and therapeutic approaches is discussed.

Impact of methylphenidate on sleep problems in adults with ADHD: a pilot polysomnography study

BACKGROUND

Attention-deficit hyperactivity disorder (ADHD) is associated with disrupted sleep and circadian rhythm. Medication for ADHD may have side effects aggravating sleep-disturbances, however beneficial effects on ADHD may contribute to improve sleep.

AIMS

This pilot study aims to examine outcomes of first time stimulant treatment on objective and subjective sleep characteristics, and psychiatric symptoms, in adult ADHD patients with pretreatment sleep problems, but without any primary sleep disorder.

METHODS

In total, 9 previously unmedicated adult ADHD subjects who reported pretreatment sleep problems, completed polysomnography (PSG) and questionnaires on subjective sleep disturbances and psychiatric symptoms. Data was collected before and after 6 weeks on first time medication with immediate-release methylphenidate (MPH-IR), mean daily dose 43 mg.

RESULTS

Subjects on-medication showed an increased percentage of Stage 2 sleep compared to their non-treated baseline (46.6% versus 55.2%, p = .011). Otherwise, there were no significant changes in PSG variables. There were no firm changes in daytime sleepiness or symptoms of sleep disturbances.

CONCLUSIONS

These findings should be interpreted cautiously given the open-label design and small sample size, and should be examined in larger studies with more rigorous study designs.

Effect of a Multi-Layer, Extended-Release Methylphenidate Formulation (PRC-063) on Sleep in Adults with ADHD: A Randomized, Double-Blind, Forced-Dose, Placebo-Controlled Trial Followed by a 6-month Open-Label Extension

BACKGROUND

The effects of stimulant treatment on sleep in adults with attention-deficit/hyperactivity disorder (ADHD) are complex and varied, with some individuals experiencing worsening of sleep but others experiencing improvement.

METHODS

Data from previously reported trials of the clinical efficacy and safety of the long-acting methylphenidate formulation PRC-063 (Adhansia XR^® in the USA; Foquest^® in Canada) in adults with ADHD were used to evaluate patient-reported sleep outcomes, as captured using the Pittsburgh Sleep Quality Index (PSQI) and adverse events of insomnia. The trials comprised 4 weeks of randomized, forced-dose PRC-063 treatment at a dose of 0 (placebo), 25, 45, 70, or 100 mg/day followed by an optional 6 months of open-label PRC-063 treatment at an individually optimized dose of 25-100 mg/day.

RESULTS

At the end of double-blind treatment, PRC-063 (all doses combined; N = 297) showed no significant difference versus placebo (N = 78) in least squares mean change in global PSQI score from baseline (- 0.7 vs. - 1.3; P = 0.0972) or in scores for each of the seven subscales of the PSQI. For patients enrolled in the open-label extension (N = 184), mean ± standard deviation global PSQI score improved from 7.8 ± 3.55 at the end of double-blind treatment to 5.8 ± 3.11 at 1 month and 5.4 ± 3.21 at 6 months (P < 0.0001). A greater proportion of patients were good sleepers (global PSQI score ≤ 5) at the end of the open-label extension (57.3%) than at baseline (20.9%) or at the end of double-blind treatment (26.0%). In a logistic regression analysis, baseline global PSQI score (odds ratio 1.491; P < 0.0001), but not randomized study treatment (P = 0.1428), was a significant predictor of poor sleep (global PSQI score > 5) at the end of double-blind treatment. Adverse event rates for insomnia (15.8 vs. 3.8%) and initial insomnia (6.1 vs. 1.3%) during double-blind treatment were higher for PRC-063 (all doses combined) than for placebo. Two patients receiving PRC-063 in the double-blind study and one patient in the open-label study were withdrawn because of insomnia adverse events.

CONCLUSIONS

Our findings indicate that, on average, PRC-063 had no significant impact on overall sleep quality in adults with ADHD. Although insomnia was observed as an adverse event, when sleep was measured over time as an outcome in its own right for patients receiving dose-optimized PRC-063 open-label, more patients showed improvement in sleep than deterioration. CLINICALTRIALS.

GOV IDENTIFER

NCT02139124 and NCT02168127.

Classification and Epidemiology of Sleep Disorders in Children and Adolescents

Sleep disturbances are common in children and adolescents but still remain unrecognized and undertreated. Several classification systems of sleep disorders are available, which include recent attempts to develop more specific nosologic categories that reflect developmental aspects of sleep. The prevalence of sleep disorders has been studied across various samples of healthy, typically developing children and those with special medical, psychiatric, and neurodevelopmental needs. Sleep disorders are highly prevalent in children and adolescents with psychiatric disorders, making it important for mental health professionals to be aware of sleep problems and to address them in the context of psychiatric comorbidities.

Insomnia Disorder in Adult Attention-Deficit/Hyperactivity Disorder Patients: Clinical, Comorbidity, and Treatment Correlates

Introduction: Several investigations have been performed on insomnia symptoms in adult attention-deficit/hyperactivity disorder (ADHD). However, the relationship between insomnia disorder and adult ADHD has been neglected in research. The main objective of the current study is to analyze the differences between adult ADHD patients with and without insomnia disorder, in terms of ADHD clinical severity, medical and psychiatric comorbidity, psychopharmacological treatment, and quality of life. Material and Methods: Two hundred and fifty-two adult patients with ADHD (mean age 37.60 ± 13.22 years; ADHD presentations-combined: 56.7%, inattentive: 39.7%, hyperactive/impulsive: 3.6%) were evaluated with an exhaustive clinical and psychological evaluation protocol including semistructured interviews (for comorbidities and ADHD assessment) and symptom rating scales for ADHD. The diagnosis of ADHD and insomnia disorder was made according to DSM-5 criteria. Furthermore, the Pittsburgh Sleep Quality Index, Insomnia Severity Index, and Epworth Sleepiness Scale were administered. Results: Insomnia disorder was found in 44.4% of adult ADHD patients and was more common in combined presentation (64.3%) and in patients with more ADHD severity. Comorbidities (both medical and psychiatric), especially mood disorders (42%), anxiety disorder (26.8%), personality disorder (39.3%), and any substance use disorder (11.6%), were associated with a higher insomnia disorder prevalence. ADHD stimulant treatment was related to lower insomnia disorder compared to patients without medication, as well as ADHD stable treatment. Additionally, worse health-related quality of life was associated with insomnia disorder. Conclusion: Insomnia disorder is highly prevalent in adult ADHD and is related to higher ADHD severity and more psychiatric and medical comorbidities. Some stimulants and stable pharmacological ADHD treatment are associated with better outcomes of insomnia disorder.

Relationships Among Delayed Sleep Phase Disorder, Emotional Dysregulation, and Affective Temperaments in Adults With Attention Deficit Hyperactivity Disorder and Cyclothymia

This study aims to explore the relationships between delayed sleep phase disorder (DSPD) and emotional dysregulation in 240 patients (134 with cyclothymia, 81 with attention deficit hyperactivity disorder [ADHD] and 25 with both conditions). DSPD was assessed using the Morningness-Eveningness Questionnaire, followed by a clinical evaluation. Affective temperaments and emotional dysregulation were also investigated through the brief version of the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego and the Reactivity, Intensity, Polarity, Stability questionnaires, respectively. Clinical variables were compared in patients with and without DSPD, and a logistic regression model was used to identify the predictive value of the clinical characteristics on the presence of DSPD. DSPD patients (19% of the total sample) were significantly younger than patients without DSPD, showed an about 4 times higher lifetime history of comorbid ADHD and cyclothymia, and reported higher scores in the irritable and cyclothymic temperamental subscales and in the affective instability and impulsivity dimensions. In the multiple logistic regression, we found a negative predictive value of increasing age on the presence of DSPD, whereas comorbid cyclothymia and ADHD and cyclothymic temperament seem to represent risk factors for DSPD.

Adult attention-deficit hyperactivity disorder and clinical correlates of delayed sleep phase disorder

The purpose of the study was to assess the prevalence and clinical correlates of Delayed Sleep Phase Disorder (DSPD) in adults with Attention-Deficit/Hyperactivity Disorder. Participants were 102 adults (Female= 27), aged 18-65 (mean age= 28.2 years), with ADHD diagnosed in adulthood. ADHD and DSPD diagnosis were made according to DSM-5 criteria. Assessing instruments included the Morningness-Eveningness Questionnaire, the brief Temperament Evaluation of Memphis, Pisa, Paris and San Diego Questionnaire, the Barratt Impulsiveness Scale, the Reactivity Intensity Polarity Stability Questionnaire-40 and the World Health Organization Disability Assessment Schedule 2.0. Epidemiological and Clinical features were compared in patients with and without DSPD. 34 out of 102 patients were classified as having a Delayed Sleep Phase Disorder. As expected, DSPD patients reported a more frequent evening chronotype. In the multivariate logistic regression analysis, Delayed Sleep Phase Disorder was significantly associated with young age, cannabis use, cyclothymic temperamental traits and severe global impairment. An early diagnosis with a proper treatment targeted to both disorders may be fundamental in order to improve the overall functioning and the outcome of adult ADHD patients.

Development of model based on clock gene expression of human hair follicle cells to estimate circadian time

Considering the effects of circadian misalignment on human pathophysiology and behavior, it is important to be able to detect an individual's endogenous circadian time. We developed an endogenous Clock Estimation Model (eCEM) based on a machine learning process using the expression of 10 circadian genes. Hair follicle cells were collected from 18 healthy subjects at 08:00, 11:00, 15:00, 19:00, and 23:00 h for two consecutive days, and the expression patterns of 10 circadian genes were obtained. The eCEM was designed using the inverse form of the circadian gene rhythm function (i.e., Circadian Time = F(gene)), and the accuracy of eCEM was evaluated by leave-one-out cross-validation (LOOCV). As a result, six genes (PER1, PER3, CLOCK, CRY2, NPAS2, and NR1D2) were selected as the best model, and the error range between actual and predicted time was 3.24 h. The eCEM is simple and applicable in that a single time-point sampling of hair follicle cells at any time of the day is sufficient to estimate the endogenous circadian time.

Delayed sleep-onset and biological age: late sleep-onset is associated with shorter telomere length

STUDY OBJECTIVES

We evaluated the relationship between leukocyte telomere length (LTL) and sleep duration, insomnia symptoms, and circadian rhythm, to test whether sleep and chronobiological dysregulations are associated with cellular aging.

METHODS

Data from the Netherlands Study of Depression and Anxiety (N = 2,936) were used at two waves 6 years apart, to measure LTL. Telomeres shorten during the life span and are important biomarkers for cellular aging. LTL was assessed by qualitative polymerase chain reaction and converted into base pair number. Sleep parameters were: sleep duration and insomnia symptoms from the Insomnia Rating Scale. Circadian rhythm variables were: indication of Delayed Sleep Phase Syndrome (DSPS), mid-sleep corrected for sleep debt on free days (MSFsc), sleep-onset time, and self-reported chronotype, from the Munich Chronotype Questionnaire. Generalized estimating equations analyzed the associations between LTL, sleep, and chronobiological factors, adjusted for baseline age, sex, North European ancestry, and additionally for current smoking, depression severity, obesity, and childhood trauma.

RESULTS

Indicators of delayed circadian rhythm showed a strong and consistent effect on LTL, after adjustment for sociodemographic and health indicators. Late MSFsc (B = -49.9, p = .004), late sleep-onset time (B = -32.4, p = .001), indication of DSPS (B = -73.8, p = .036), and moderately late chronotype in adulthood (B = -71.6, p = .003) were associated with significantly shorter LTL across both waves; whereas sleep duration and insomnia symptoms were not. Extremely early chronotype showed significantly less LTL shortening than intermediate chronotype (B = 161.40, p = .037). No predictors showed accelerated LTL attrition over 6 years.

CONCLUSIONS

Individuals with delayed circadian rhythm have significantly shorter LTL, but not faster LTL attrition rates.

Objective QbTest and subjective evaluation of stimulant treatment in adult attention deficit-hyperactivity disorder

Purpose:

To evaluate the QbTest as an objective measure versus self-reported ADHD Rating Scale (ADHD-RS) before and during stimulant treatment in adults with ADHD.

Patients and methods:

We used the subjective ADHD Rating Scale (ADHD-RS), and the objective computerized QbTest, which is a 20-minute unconditional identical pairs test that measures attention, impulsivity, and also hyperactivity using a motion-tracking system. Patients were assessed before (baseline) and during medical treatment with stimulants (follow-up) in an observational study design.

Results:

Data of n = 145 patients at baseline and n = 82 patients at follow-up were analyzed. There were significant symptom reductions on all symptom domains, but correlations between the tests were weak. Improvement on the QbTest was independent of the patient's age, gender, educational level, ADHD subtype, co-morbid disorders, and use of other medications. Patients with worst QbTest results at baseline showed most improvement at follow-up. The QbTest was more sensitive to medication effects than the ADHD-RS. QbTest objectified clinical significant medication effect in 54% of patients who subjectively did not report any clinical effects.

Discussion:

Symptoms dimensions of objective and subjective tests refer to different psychological constructs.

Conclusion:

The QbTest is a valuable addition to existing subjective measures to assess medication effects in ADHD patients who have difficulties reporting treatment effects.

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.

The effects of emotional lability, mind wandering and sleep quality on ADHD symptom severity in adults with ADHD

Mind wandering, emotional lability and sleep quality are currently mostly independently investigated but are all interlinked and play a major role is adult attention-deficit/ hyperactivity disorder (ADHD). Emotional lability is a core feature of the disorder, excessive mind wandering has recently been linked to symptoms and impairments of ADHD and poor sleep quality is experienced by a clear majority of adults with ADHD. All three phenomena lead to functional impairment in ADHD, however their relationship to each other and to ADHD symptom severity is not well understood. Here we used serial multiple mediation models to examine the influence of mind wandering, sleep quality and emotional lability on ADHD symptom severity. 81 adults diagnosed with ADHD participated in this study. We found that mind wandering and emotional lability predicted ADHD symptom severity and that mind wandering, emotional lability and sleep quality were all linked and significantly contributed to the symptomatology of adult ADHD. Mind wandering was found to lead to emotional lability which in turn lead to ADHD symptom severity; and poor sleep quality was found to exacerbate mind wandering leading to ADHD symptoms. Future research should employ objective on-task measures of mind wandering, sleepiness and emotional lability to investigate the neural basis of these impairing deficits in ADHD.

Intraindividual variability of sleep/wake patterns in adolescents with and without attention-deficit/hyperactivity disorder

BACKGROUND

Prior studies examining the sleep of adolescents with and without attention-deficit/hyperactivity disorder (ADHD) have relied on mean values such as average sleep duration, which masks intraindividual variability (IIV). The objective was to investigate whether adolescents with ADHD have greater IIV of sleep/wake patterns than adolescents without ADHD using actigraphy and daily sleep diaries.

METHOD

Adolescents (ages 13.17 ± 0.40 years; 45% female) with (n = 162) and without (n = 140) ADHD were recruited from middle schools at two sites. Participants wore actigraphs and completed sleep diaries for an average of 2 weeks.

RESULTS

Multilevel models were conducted with sex, sleep medication use, ADHD medication use, number of days with data, and social jetlag controlled for in analyses. For actigraphy, adolescents with ADHD had greater variability for time in bed, sleep onset and offset, and wake after sleep onset than adolescents without ADHD. For sleep diary data, adolescents with ADHD had greater variability in bedtime, wake time, sleep duration, sleep onset latency, sleep quality, and night wakings than adolescents without ADHD. Social jetlag was a significant predictor of variability in sleep measures based on both actigraph and daily diaries; however, ADHD status was not associated with social jetlag.

CONCLUSIONS

This is the first study to show that adolescents with ADHD have more variable sleep/wake patterns than their peers using both objective and subjective sleep measures. IIV of sleep/wake patterns may be important for clinicians to assess and monitor as part of treatment. Research is needed to understand the mechanisms underlying increased IIV of sleep/wake patterns in adolescents with ADHD and potential consequences for daytime functioning.

Effects and clinical feasibility of a behavioral treatment for sleep problems in adult attention deficit hyperactivity disorder (ADHD): a pragmatic within-group pilot evaluation

BACKGROUND

Sleep disturbances, including insomnia, are common in adult Attention Deficit Hyperactivity Disorder (ADHD). Treatment of choice for insomnia is cognitive behavioral therapy (CBT-i), but evidence is lacking for CBT-i in patients with ADHD. The purpose of this study was to investigate if patients with insomnia and other sleep problems, at a specialist clinic for ADHD, benefit from a group delivered behavioral treatment based on CBT-i; whether insomnia severity improves following this treatment.

METHODS

This pragmatic within-group pilot study with a pre to post and three-month follow-up design was set at a specialist psychiatric out-patient clinic for adult ADHD. As an adjunct to care-as-usual at the clinic, a CBT-i-based group treatment targeting several sleep problems prevalent in the ADHD-population, was offered as 10 weekly 90-min group sessions and scheduled telephone support. All outcome measures were subjectively reported by participants. Data analyzed with dependent t-tests according to intent-to-treat.

RESULTS

Nineteen patients (37 [SD 13.7] years; 68% female) with ADHD and subjectively reported sleep problems provided informed consent and pre-treatment measures. Patients had suffered from sleep problems for 15.3 [SD 13.4] years, 42% used sleep medications, 79% used stimulant medication(s). At post-treatment, insomnia severity (Insomnia Severity Index; score range 0-28) had improved with 4.5 points (95% CI, 2.06-6.99, p = .002), at 3 months with 6.8 points (95% CI, 4.71-8.91, p < .0001) from pre-treatment.

CONCLUSIONS

CBT-i adjusted for ADHD is promising for improving insomnia severity in adult patients at specialist psychiatric out-patient clinics, who suffer from ADHD and sleep disturbances.

TRIAL REGISTRATION

Study registered with the Regional ethical review board in Stockholm, January 13th 2016, Study id: 2015/2078-31/1. Study registered retrospectively with Clinicaltrials.org, February 21st 2019, ID: NCT03852966.

Subclinical Scores in Self-Report Based Screening Tools for Attention Deficits Correlate With Cognitive Traits in Typical Evening-Type Adults Tested in the Morning

Previous studies suggest that in adolescents and young adults, evening chronotype is a subclinical factor in physical, cognitive, and psychiatric fitness; poor sleep habits and larger misalignment with the social schedule constraints may exacerbate symptoms of inattention, impulsivity and the risks for detrimental behaviors. The influence of chronotype on neurocognitive performance during morning hours and scores in self-reports about attention deficit symptoms (ADS) and executive functioning, was explored in 42 healthy young university students (29 women), divided to evening type (ET) and combined morning/intermediate type (MT/IT) groups. Evening chronotypes scored significantly higher in the questionnaires of inattention Adult ADHD Self-Report Scale (ASRS-6) (MT/IT: 1.62 ± 1.59; ET: 2.71 ± 1.62, p < 0.05) and day-time sleepiness Epworth scale (MT/IT: 7.19 ± 5.17; ET: 11.48 ± 5.26, p < 0.01), reported lower subjective alertness (MT/IT: 63.02 ± 21.40; ET: 40.76 ± 17.43, p < 0.001), and had slower reaction times (MT/IT: 321.47 ± 76.81; ET: 358.94 ± 75.16, p < 0.05) during tests, compared to non-evening chronotypes. Nevertheless, ETs did not significantly differ in self-reports of executive functioning in the Behavioral Rating Inventory of Executive Functions-A (BRIEF-A) from non-ETs. The scores on standard self-report screening tools for ADS and executive functioning (ASRS-6, BRIEF-A-Metacognition) correlated with eveningness. We conclude that eveningness, subjective sleepiness and low arousal levels during morning can present as subclinical Attention Deficit and Hyperactivity Disorder (ADHD) symptoms in typical young adults with no evident sleep problems. Self-report based screening tools for ADS and executive functioning reflect chronotype-related traits in healthy young adults. Strong eveningness may bias the results of neurocognitive performance screening for ADHD when administered at morning hours.

Chronotypical characteristics and related miR-142-3p levels of children with attention deficit and hyperactivity disorder

To compare children with Attention Deficit and Hyperactivity Disorder (ADHD) and a healthy control group in terms of chronotype characteristics and miRNA-142-3p/miRNA-378 levels. 50 children with ADHD and 44 healthy children were included in the study. Childhood Chronotype Questionnaire was used to identify the chronotype preferences of children. Serum miR-142-3p and miR- 378 levels were determined. Preference for nighttime was higher in children with ADHD. Additionally, a night preference was found to be associated with attention deficit in both groups. While a significant correlation was found between the psychopathology rate in mothers and the presence of ADHD, there was no such correlation in fathers. In the comparison between children with ADHD and the control group, no significant difference was found between miRNA levels. Both the miR-142-3p and miR-378 values of the children with ADHD that have immediate relatives with a psychiatric disorder were lower, compared to control group. We found that shift to night preference in the circadian rhythm was higher and this preference was associated with attention deficit in the children with ADHD. In addition, the presence of psychopathology in the family and the mother's psychopathology affected the miR-142-3p and miR378 levels.

Adult ADHD and Comorbid Somatic Disease: A Systematic Literature Review

OBJECTIVE

To systematically review, synthesize, and appraise available evidence, connecting adult ADHD with somatic disease.

METHOD

Embase, Psychinfo, and Medline databases were searched for studies published from 1994 to 2015 addressing adult ADHD and somatic comorbidity. Somatic conditions were classified according to International Classification of Diseases (ICD-10) codes. Levels of evidence were graded as inconclusive, tentative, or well documented.

RESULTS

Most of the 126 studies included in the qualitative synthesis were small and of modest quality. Obesity, sleep disorders, and asthma were well-documented comorbidities in adult ADHD. Tentative evidence was found for an association between adult ADHD and migraine and celiac disease. In a large health registry study, cardiovascular disease was not associated with adult ADHD.

CONCLUSION

There are few large systematic studies using standardized diagnostic criteria evaluating adult ADHD and somatic comorbidities. Significant associations are found between adult ADHD and several somatic diseases, and these are important to consider when assessing and treating either adult ADHD or the somatic diseases.

Sleep disorders in patients with ADHD: impact and management challenges

Attention deficit/hyperactivity disorder (ADHD) is one of the most commonly diagnosed disorders in childhood, enduring through adolescence and adulthood and presenting with symptoms of inattention, hyperactivity, and/or impulsivity and significantly impairing functioning. Primary sleep disorders such as sleep-disordered breathing, restless leg syndrome, circadian rhythm sleep disorder, insomnia, and narcolepsy are commonly comorbid in these individuals but not often assessed and are therefore often left untreated. Sleep disturbances in individuals with ADHD can result in significant functional impairments that affect mood, attention, behavior, and ultimately school/work performance and quality of life. Previous reviews have described findings related to sleep but have neglected to examine potential impacts of these sleep disorders and ADHD on daytime functioning. This review investigates empirical findings pertaining to sleep abnormalities and related cognitive, behavioral, emotional, and physical impairments in individuals with ADHD and comorbid primary sleep disorders across the life span. It discusses implications to management and highlights existing limitations and recommended future directions.

Delayed sleep-wake phase disorder

Delayed sleep-wake phase disorder (DSWPD) is the most commonly encountered of the circadian rhythm sleep-wake disorders (CRSDs), and is often confused with sleep initiation insomnia. It typically emerges in teenage years and persists into adulthood. In essence, people with the disorder have an abnormally delayed major sleep episode relative to the dark phase of the solar cycle, and hence great difficulty initiating sleep at an appropriately early time, and, as a knock-on effect, waking at a desirable time in the morning, leading to chronic, and often quite severe sleep restriction trying to conform to a 9 to 5 schedule. As a result, sleep on free days is often extended in compensation. When released from such schedule constraints, sleep duration and quality is normal; it is just delayed. This review highlights elements of our current understanding of the epidemiology, associations and pathophysiology of the disorder, before discussing how some of our knowledge of sleep and circadian physiology can be applied to guide treatment of it.

Persistence and Adherence to Psychostimulants, and Psychological Well-Being Up to 3 Years After Specialized Treatment of Adult Attention-Deficit/Hyperactivity Disorder: A Naturalistic Follow-Up Study

BACKGROUND

Little is known about the long-term persistence and adherence of psychostimulant use in adults with attention-deficit/hyperactivity disorder (ADHD) and its relationship to their psychological well-being.

METHODS

The persistence and adherence to psychostimulants and psychological well-being were examined in adults with ADHD in a naturalistic follow-up, starting directly after discharge from their specialized treatment of ADHD at an outpatient ADHD clinic. Ninety-six patients were included at the time of discharge, who were interviewed by telephone at 6 months, 1 year, and 3 years after discharge.

RESULTS

At the time of discharge, 78% used a psychostimulant prescribed by a psychiatrist. Of those on psychostimulants at the time of discharge, approximately half still used any of these psychostimulants 3 years after discharge. However, adherence rates were good for those who persisted to use psychostimulants. The female sex and middle educational level (relative to a higher educational level) were near-significantly related to nonpersistence, and having a higher educational level and the combined ADHD subtype were related to nonadherence. In turn, nonadherence was related to worse general functioning, lower mood, and poorer sleep quality.

CONCLUSIONS

The importance of adherence should be discussed at the time of discharge, especially with female ADHD patients, those with a higher educational level, and those with a combined ADHD subtype, because nonadherence is associated with poorer outcomes.

Biological dysrhythm in remitted bipolar I disorder

BACKGROUND

Recent treatment guidelines support treatment of biological rhythm abnormalities as a part of treatment of bipolar disorder, but still, literature examining various domains (Sleep, Activity, Social, and Eating) of biological rhythm and its clinical predictors are less.

OBJECTIVES

The main aim of our study is to compare various domains of biological rhythm among remitted bipolar I subjects and healthy controls. We also explored for any association between clinical variables and biological rhythm among bipolar subjects.

METHODS

40 subjects with Bipolar I disorder and 40 healthy controls who met inclusion and exclusion criteria were recruited for the study. Diagnoses were ascertained by a qualified psychiatrist using MINI 5.0. Sociodemographic details, biological rhythm (BRIAN-Biological Rhythm Interview of assessment in Neuropsychiatry) and Sleep functioning (PSQI- Pittsburgh Sleep Quality Index) were assessed in all subjects.

RESULTS

Mean age of the Bipolar subjects and controls were 41.25±11.84years and 38.25±11.25 years respectively. Bipolar subjects experienced more biological rhythm disturbance when compared to healthy controls (total BRIAN score being 34.25±9.36 vs 28.2±6.53) (p=0.002). Subsyndromal depressive symptoms (HDRS) had significant positive correlation with BRIAN global scores(r=0.368, p=0.02). Linear regression analysis showed that number of episodes which required hospitalization (β=0.601, t=3.106, P=0.004), PSQI (β=0.394, t=2.609, p=0.014), HDRS (β=0.376, t=2.34, t=0.036) explained 31% of variance in BRIAN scores in remitted bipolar subjects.

CONCLUSION

Biological rhythm disturbances seem to persist even after clinical remission of bipolar illness. More studies to look into the impact of subsyndromal depressive symptoms on biological rhythm are needed.

Insomnia in adult attention-deficit/hyperactivity disorder: A comparison with borderline personality disorder population in a clinical setting and control participants

OBJECTIVES

Many adults with attention-deficit/hyperactivity disorder (ADHD) report sleeping difficulties. The relationship between sleep and ADHD is poorly understood, and shows discrepancies between subjective and objective measures. In order to determine the specificity of sleep-associated symptoms in ADHD, subjective sleep assessments among ADHD adult patients were compared with control subjects and with individuals suffering from borderline personality disorder (BPD).

METHODS

129 outpatients with ADHD, 70 with BPD (including 17 patients with BPD and ADHD comorbidity), and 65 control participants were assessed for sleep quality, insomnia, and sleepiness, using the Pittsburgh Sleep Quality Index (PSQI), the Insomnia Severity Index (ISI), and the Epworth Sleepiness Scale (ESS).

RESULTS

ADHD- and BPD-sufferers achieved higher insomnia and lower sleep quality scores than control subjects. Clinical groups did not differ in terms of sleep quality, although insomnia was more severe among BPD patients. Depression scores explained most of sleep symptoms, but even when controlling for depression, ADHD sufferers showed higher sleep latency. Inattentive symptoms were associated with somnolence, while hyperactive/impulsive symptoms were associated with insomnia and lower sleep efficiency.

CONCLUSION

Sleep-related symptoms associated with ADHD were partly explained by non-specific factors, especially depression symptoms. In a dimensional perspective, hyperactive and inattentive symptoms were associated with specific sleep symptoms.

Atypical sensory profiles as core features of adult ADHD, irrespective of autistic symptoms

BACKGROUND

Abnormal sensory sensitivity is a feature of autism-spectrum disorder (ASD), but is also reported in attention-deficit/hyperactivity disorder (ADHD). In many cases, ADHD and ASD are comorbid. This study investigated the prevalence of sensory hyper- and hyposensitivity among adults with ADHD, controlling for autistic symptoms.

METHOD

One hundred and sixteen adults diagnosed with ADHD completed the Adolescent/Adult Sensory Profile-NL (AASP-NL) and the Autism-spectrum Quotient (AQ) questionnaires. Prevalences of hyper- and hyposensitivity and autism-spectrum symptoms were compared to norm values. Multivariate binary logistic regressions were used to determine the association of autistic symptoms, age, gender, ADHD subtype, self-reported severity of ADHD symptoms, comorbid disorders, and use of medication on the sensory hypo- and hypersensitivity in adults with ADHD.

RESULTS

Adults with ADHD had more autistic symptoms, and they had both more hyper- and hyposensitivity compared to norm groups. This was especially apparent in the Activity level and Auditory sensory modalities. Sensory hypo- and hypersensitivity were both related to an increased ADHD score, even showing a dose-response relationship, but not to any autistic symptom or comorbid disorder. As much as 43% of the females with ADHD reported sensory hypo- and/or hypersensitivity, compared to 22% of the men.

CONCLUSIONS

Sensory hypo- and hypersensitivity may be viewed as key features of adult ADHD, especially in females, regardless of any autistic symptoms. Future research should be directed at the implications of this sensory dysregulation for the understanding of the pathophysiology of (female) ADHD, and on the usefulness of assessment of atypical sensory profiles in the diagnostic procedure of ADHD in adults.

Procedural Memory Consolidation in Attention-Deficit/Hyperactivity Disorder Is Promoted by Scheduling of Practice to Evening Hours

In young adults without attention-deficit/hyperactivity disorder (ADHD) training on a novel movement sequence results not only in large within-session (online) gains in task performance but also in additional (delayed, off-line) gains in the performance, expressed after an interval of sleep. In contrast, young people with ADHD, given an identical practice, were shown to improve online but expressed much smaller delayed gains overnight. As delayed gains in performance are taken to reflect procedural ("how to") memory consolidation processes, this may explain skill learning deficits in persons with ADHD. However, motor training is usually provided in morning sessions, and, given that persons with ADHD are often evening types, chronobiological constraints may constitute a hidden factor. Here, we tested the hypothesis that evening training, compared to morning training, would result in larger overnight consolidation gains following practice on a novel motor task in young women with ADHD. Participants with (N = 25) and without (N = 24) ADHD were given training on a finger opposition sequence tapping task, either in the morning or at evening. Performance was assessed before and immediately after training, overnight, and at 2 weeks post-training. Individuals with ADHD reported a general preference for evening hours. Evening training was equally effective in participants with and without ADHD, both groups showing robust consolidation gains in task performance overnight. However, the ability to express delayed gains overnight was significantly reduced in participants with ADHD if trained in the morning. Typical peers were as effective in expressing overnight consolidation phase gains irrespective of the time-of-day wherein the training session was afforded. Nevertheless, even after morning training, participants with ADHD fully retained the gains acquired within the first 24 h over an interval of about 2 weeks. Our results suggest that procedural memory consolidation processes are extant and effective in ADHD, but require that specific biobehavioral conditions be met. The affordance of training in the evening hours can relax some of the constraints on these processes in ADHD. The current results are in line with the notion that the control of what is to be retained in procedural memory is atypical or more stringent in ADHD.

ADHD, circadian rhythms and seasonality

OBJECTIVE

We evaluated whether the association between Adult Attention-Deficit/Hyperactivity Disorder (ADHD) and Seasonal Affective Disorder (SAD) was mediated by the circadian rhythm.

METHOD

Data of 2239 persons from the Netherlands Study of Depression and Anxiety (NESDA) were used. Two groups were compared: with clinically significant ADHD symptoms (N = 175) and with No ADHD symptoms (N = 2064). Sleep parameters were sleep-onset and offset times, mid sleep and sleep duration from the Munich Chronotype Questionnaire. We identified the prevalence of probable SAD and subsyndromal SAD using the Seasonal Pattern Assessment Questionnaire (SPAQ). Clinically significant ADHD symptoms were identified by using a T score>65 on the Conners Adult ADHD Rating Scale.

RESULTS

The prevalence of probable SAD was estimated at 9.9% in the ADHD group (vs. 3.3% in the No ADHD group) and of probable s-SAD at 12.5% in the ADHD group (vs 4.6% in the No ADHD group). Regression analyses showed consistently significant associations between ADHD symptoms and probable SAD, even after adjustment for current depression and anxiety, age, sex, education, use of antidepressants and benzodiazepines (B = 1.81, p < 0.001). Late self-reported sleep onset was an important mediator in the significant relationship between ADHD symptoms and probable SAD, even after correction for confounders (total model effects: B = 0.14, p ≤ 0.001).

CONCLUSION

Both seasonal and circadian rhythm disturbances are significantly associated with ADHD symptoms. Delayed sleep onset time in ADHD may explain the increase in SAD symptoms. Treating patients with SAD for possible ADHD and delayed sleep onset time may reduce symptom severity in these complex patients.

Attention-deficit hyperactivity disorder symptoms add risk to circadian rhythm sleep problems in depression and anxiety

BACKGROUND

Comorbid ADHD symptoms may partly account for circadian rhythm disturbances in depression and anxiety disorders.

METHODS

Self-reported sleep characteristics of 2090 participants in the Netherlands Study of Depression and Anxiety were assessed using the Munich Chronotype Questionnaire. We defined 3 groups: healthy controls (HC), persons with lifetime depression and/or anxiety disorders (LDA), and those with both LDA and high ADHD symptoms (LDA+ADHD), using the Conner's Adult ADHD Rating Scale.

RESULTS

Sleep characteristics were least favorable in the LDA+ADHD group. Important group differences between LDA+ADHD, LDA and HC were found for extremely late chronotype (12% vs. 5% vs. 3%; p<.001), sleep duration <6h (15% vs. 5% vs. 4%; p<.001), and for an indication of the Delayed Sleep Phase Syndrome (DSPS; 16% vs. 8% vs. 5%; p<.001). After adjustment for covariates, including depression and anxiety, presence of ADHD symptoms increased the odds ratio for late chronotype (OR=2.6; p=.003), indication of DSPS (OR=2.4; p=.002), and sleep duration <6h (OR=2.7; p=.007).

LIMITATIONS

ADHD conceptually overlaps with symptom presentation of depression and anxiety. We used a cross-sectional study design, and used self reported sleep characteristics.

CONCLUSIONS

High ADHD symptoms were associated with an increased rate of circadian rhythm sleep disturbances in an already at-risk population of people with depression and/or anxiety disorders. Circadian rhythm sleep disorders, as often seen in ADHD are not entirely due to any comorbid depression and/or anxiety disorder. Adequate treatment of such sleep problems is needed and may prevent serious health conditions in the long term.

Associations of pineal volume, chronotype and symptom severity in adults with attention deficit hyperactivity disorder and healthy controls

The pineal gland, as part of the human epithalamus, is the main production site of peripheral melatonin, which promotes the modulation of sleep patterns, circadian rhythms and circadian preferences (morningness vs. eveningness). The present study analyses the pineal gland volume (PGV) and its association with circadian preferences and symptom severity in adult ADHD patients compared to healthy controls. PGV was determined manually using high-resolution 3T MRI (T1-magnetization prepared rapid gradient echo) in medication free adult ADHD patients (N=74) compared to healthy controls (N=86). Moreover, the Morningness-Eveningness Questionnaire (MEQ), the ADHD Diagnostic Checklist and the Wender-Utah Rating Scale were conducted. PGV differed between both groups (patients: 59.9±33.8mm(3); healthy controls: 71.4±27.2mm(3), P=0.04). In ADHD patients, more eveningness types were revealed (patients: 29%; healthy controls: 17%; P=0.05) and sum scores of the MEQ were lower (patients: 45.8±11.5; healthy controls 67.2±10.1; P<0.001). Multiple regression analyses indicated a positive correlation of PGV and MEQ scores in ADHD (β=0.856, P=0.003) but not in healthy controls (β=0.054, P=0.688). Patients' MEQ scores (β=-0.473, P=0.003) were negatively correlated to ADHD symptoms. The present results suggest a linkage between the PGV and circadian preference in adults with ADHD and an association of the circadian preference to symptom severity. This may facilitate the development of new chronobiological treatment approaches for the add-on treatment in ADHD.

Circadian rhythms and attention deficit hyperactivity disorder: The what, the when and the why

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental condition characterised by impulsivity, inattention and hyperactivity. Aside from these core psychopathologies, sleep disturbances are found to be highly comorbid with ADHD, and indeed dysregulated sleep may contribute to some of the symptoms of the disorder. It is not clear how sleep disturbances come to be so common in ADHD, but one putative mechanism is through the circadian timekeeping system. This system underpins the generation of near 24-hour rhythms in a host of physiological, behavioural and psychological parameters, and is a key determinant of the sleep/wake cycle. In this paper we review the evidence for sleep and circadian rhythm disturbance in ADHD, examine the possible mechanistic links between these factors and the disorder and discuss future directions through which the circadian clock can be targetted for ADHD symptom relief.

ADHD-associated dopamine transporter, latrophilin and neurofibromin share a dopamine-related locomotor signature in Drosophila

Attention-deficit/hyperactivity disorder (ADHD) is a common, highly heritable neuropsychiatric disorder with hyperactivity as one of the hallmarks. Aberrant dopamine signaling is thought to be a major theme in ADHD, but how this relates to the vast majority of ADHD candidate genes is illusive. Here we report a Drosophila dopamine-related locomotor endophenotype that is shared by pan-neuronal knockdown of orthologs of the ADHD-associated genes Dopamine transporter (DAT1) and Latrophilin (LPHN3), and of a gene causing a monogenic disorder with frequent ADHD comorbidity: Neurofibromin (NF1). The locomotor signature was not found in control models and could be ameliorated by methylphenidate, validating its relevance to symptoms of the disorder. The Drosophila ADHD endophenotype can be further exploited in high throughput to characterize the growing number of candidate genes. It represents an equally useful outcome measure for testing chemical compounds to define novel treatment options.

Multivariate Imaging Genetics Study of MRI Gray Matter Volume and SNPs Reveals Biological Pathways Correlated with Brain Structural Differences in Attention Deficit Hyperactivity Disorder

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder affecting children, adolescents, and adults. Its etiology is not well understood, but it is increasingly believed to result from diverse pathophysiologies that affect the structure and function of specific brain circuits. Although one of the best-studied neurobiological abnormalities in ADHD is reduced fronto-striatal-cerebellar gray matter (GM) volume, its specific genetic correlates are largely unknown.

METHODS

In this study, T1-weighted MR images of brain structure were collected from 198 adolescents (63 ADHD-diagnosed). A multivariate parallel independent component analysis (Para-ICA) technique-identified imaging genetic relationships between regional GM volume and single nucleotide polymorphism data.

RESULTS

Para-ICA analyses extracted 14 components from genetic data and 9 from MR data. An iterative cross-validation using randomly chosen subsamples indicated acceptable stability of these ICA solutions. A series of partial correlation analyses controlling for age, sex, and ethnicity revealed two genotype-phenotype component pairs significantly differed between ADHD and non-ADHD groups, after a Bonferroni correction for multiple comparisons. The brain phenotype component not only included structures frequently found to have abnormally low volume in previous ADHD studies but was also significantly associated with ADHD differences in symptom severity and performance on cognitive tests frequently found to be impaired in patients diagnosed with the disorder. Pathway analysis of the genotype component identified several different biological pathways linked to these structural abnormalities in ADHD.

CONCLUSION

Some of these pathways implicate well-known dopaminergic neurotransmission and neurodevelopment hypothesized to be abnormal in ADHD. Other more recently implicated pathways included glutamatergic and GABA-eric physiological systems; others might reflect sources of shared liability to disturbances commonly found in ADHD, such as sleep abnormalities.

Circadian rhythm disruption as a link between Attention-Deficit/Hyperactivity Disorder and obesity?

OBJECTIVE

Patients with Attention-Deficit/Hyperactivity Disorder (ADHD) have a high prevalence of obesity. This is the first study to investigate whether circadian rhythm disruption is a mechanism linking ADHD symptoms to obesity.

METHODS

ADHD symptoms and two manifestations of circadian rhythm disruption: sleep problems and an unstable eating pattern (skipping breakfast and binge eating later in the day) were assessed in participants with obesity (n= 114), controls (n= 154), and adult ADHD patients (n= 202).

RESULTS

Participants with obesity had a higher prevalence of ADHD symptoms and short sleep on free days as compared to controls, but a lower prevalence of ADHD symptoms, short sleep on free days, and an unstable eating pattern as compared to ADHD patients.We found that participants with obesity had a similar prevalence rate of an unstable eating pattern when compared to controls. Moreover, mediation analyses showed that both sleep duration and an unstable eating pattern mediated the association between ADHD symptoms and body mass index (BMI).

CONCLUSION

Our study supports the hypothesis that circadian rhythm disruption is a mechanism linking ADHD symptoms to obesity. Further research is needed to determine if treatment of ADHD and circadian rhythm disruption is effective in the prevention and treatment of obesity in patients with obesity and/or ADHD.

Lack of neuronal nitric oxide synthase results in attention deficit hyperactivity disorder-like behaviors in mice

Nitric oxide (NO) is an important molecule for the proper development and function of the central nervous system. In this study, we investigated the behavioral alterations in the neuronal NO synthase knockout mice (NOS1 KO) with a deficient NO production mechanism in the brain, characterizing it as a potential rodent model for attention deficit hyperactivity disorder (ADHD). NOS1 KO exhibited higher locomotor activity than their wildtype counterparts in a novel environment, as measured by open field (OF) test. In a 2-way active avoidance paradigm (TWAA), we found sex-dependent effects, where male KO displayed deficits in avoidance and escape behavior, sustained higher incidences of shuttle crossings, and higher incidences of intertrial interval crossings, suggesting learning, and/or performance impairments. On the other hand, female KO demonstrated few deficits in TWAA. Molsidomine (MSD), a NO donor, rescued TWAA deficits in male KO when acutely administered before training. In a passive avoidance paradigm, KO of both sexes displayed significantly shorter step-through latencies after training. Further, abnormal spontaneous motor activity rhythms were found in the KO during the dark phase of the day, indicating dysregulation of rhythmic activities. These data indicate that NOS1 KO mimics certain ADHD-like behaviors and could potentially serve as a novel rodent model for ADHD.