Attention deficit disorders and sleep/arousal disturbance

Impact of the Allergic Therapeutic Adherence in Children with Allergic Rhinitis and ADHD: A Pilot Study

BACKGROUND

Allergic rhinitis (AR) is the most common chronic allergic disease in children. Several studies have shown an association between attention deficit hyperactivity disorder (ADHD) and allergies, especially AR. Patients with ADHD usually have poor therapeutic adherence, and untreated AR symptoms may worsen the quality of life of patients.

METHODS

The aim of our study was to analyse therapeutic adherence in patients with ADHD and AR and estimate the impact of the adherence on ADHD symptoms. Total Nasal Symptoms Score (TNSS), Paediatric or Adolescent Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ 6-12 years; ARQLQ 13-17 years), Swanson, Nolan, and Pelham version IV scale (SNAP-IV), and Medication Assessment Questionnaire (MGL MAQ) were recorded.

RESULTS

In the AR-ADHD group, a positive correlation between TNSS and SNAP-IV subscales was found: worse AR symptoms were related to a negative effect on ADHD scores. AR-ADHD patients with better ADHD therapeutic adherence showed higher AR symptoms and higher oppositional defiant disorder scores in the SNAP-IV questionnaire.

CONCLUSIONS

Our results suggest that better adherence to AR therapy (oral antihistamines and/or intranasal corticosteroids, INCS) is associated with a reduction in inattention symptoms in children with ADHD. This data could prove to be fundamental for the psychic outcome of these patients.

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.

Kinetic pupillary size using Pentacam in myopia

Purpose

To compare if the kinetic pupillary changes differs between high myopia (HM) and low/moderate myopia by Pentacam.

Setting

Chinese People's Liberation Army (PLA) General Hospital, Beijing, China.

Design

Comparative study.

Methods

In this cross-sectional retrospective study, 44 eyes of 44 patients were recruited in the Refractive Surgery Center of Chinese PLA General Hospital. Eyes were divided into two groups according to the refractive error: low/moderate myopia (22 eyes; -2.99 ± 1.09 D) and HM (22 eyes, -12.93 ± 3.44 D). At the beginning of the experiment, we made trials of scanning one false pupil by Pentacam. All patients underwent the Pentacam examination three times. Pupillary diameters (PD) during the scan process and other parameters were measured using the Pentacam. Coefficient variations of PD (CV) during the different scanning periods were analyzed comparatively between the two groups.

Results

Pentacam once time output 25 Scheimpflug images, with 13 ones during the period from 1st to 1.5th s and 12 ones during the period from 2.5th to 3rd s after the scanning onset. For the spatial order on all the 25 meridians, 13 Scheimpflug images came out when the Pentacam rotated from 60° to 153°meridians and the remaining 12 Scheimpflug images from 161° to 245° meridians. Among pupillary parameters, no statistical significance existed in PD25, PD13, and PD12 (pupil diameter's mean from all, former 13 and remaining 12 of 25 Scheimpflug images, respectively) (P > 0.05) between the two groups. However, there were statistically significant differences in CV25 and CV13 (coefficient variation of the pupil diameters from all and former 13 of 25 images, respectively) (P < 0.001), with no statistical significance in CV12 (coefficient variation of the pupil diameters from remaining 12 of 25 images) between both groups.

Conclusion

Twenty-five Scheimpflug images on Pentacam had the temporal and the spatial orders. CV in eyes with HM was lower than that in eyes with low/moderate myopia in a certain period of the Pentacam scan. Kinetic pupillary size in HM changed more slowly than that in low/moderate myopia during some scanning period analogous to the phasic response of the pupil reflex.

The song of Anorexia Nervosa: a specific evoked potential response to musical stimuli in affected participants

PURPOSE

Research applying electroencephalography (EEG) to Anorexia Nervosa (AN) is still limited, even though in other psychiatric disorders EEG has permitted to find out the hallmarks of the disorder. The aim of the study was to explore whether EEG basal activity and reactivity to musical stimulation differ in participants with AN as compared to healthy subjects (HS).

METHODS

Twenty female participants (respectively 10 with AN and 10 healthy controls) were administered a battery of psychometric tests and underwent EEG under three different conditions: (1) at baseline; (2) after a generic music stimulation; and (3) after a favorite musical stimulation.

RESULTS

In participants with AN, basal EEG showed the higher absolute amplitude of cortical slow waves (theta) in the parieto-occipital and temporal derivations, with a deficit in the beta band. In AN, there was a higher N100 latency and a reduced P300 latency compared to HS. While the N100 and P300 latencies were sensitive to the musical stimulus in HS, there was no difference after music stimulation in AN.

CONCLUSION

These data suggest that AN is accompanied by a state of brain hyperarousal with abnormal reactivity to environmental stimuli, similar to the state of HS after musical stimulation. If confirmed, this finding may have treatment implications.

LEVEL OF EVIDENCE

III, Evidence obtained from well-designed cohort or case-control analytic studies.

The key role of daytime sleepiness in cognitive functioning of adults with attention deficit hyperactivity disorder

Background.

Adults with attention deficit hyperactivity disorder (ADHD) frequently suffer from sleep problems and report high levels of daytime sleepiness compared to neurotypical controls, which has detrimental effect on quality of life.

Methods.

We evaluated daytime sleepiness in adults with ADHD compared to neurotypical controls using an observer-rated sleepiness protocol during the Sustained Attention Response Task as well as electroencephalogram (EEG) slowing, a quantitative electroencephalographic measure collected during a short period of wakeful rest.

Results.

We found that adults with ADHD were significantly sleepier than neurotypical controls during the cognitive task and that this on-task sleepiness contributed to cognitive performance deficits usually attributed to symptoms of ADHD. EEG slowing predicted severity of ADHD symptoms and diagnostic status, and was also related to daytime sleepiness. Frontal EEG slowing as well as increased frontal delta were especially prominent in adults with ADHD. We have validated and adapted an objective observer-rated measure for assessing on-task sleepiness that will contribute to future sleep research in psychology and psychiatry.

Conclusions.

These findings indicate that the cognitive performance deficits routinely attributed to ADHD and often conceptualized as cognitive endophenotypes of ADHD are largely due to on-task sleepiness and not exclusively due to ADHD symptom severity. Daytime sleepiness plays a major role in cognitive functioning of adults with ADHD.

Excessive Daytime Sleepiness Measurements in Children With Attention Deficit Hyperactivity Disorder

Attention deficit hyperactivity disorder (ADHD) is the most commonly diagnosed neurodevelopmental disorder in childhood. It is a heterogeneous disorder in terms of clinical presentation that is probably due to the frequent occurrence of comorbidity. Children with ADHD more frequently report sleep disorders (notably delayed sleep phase syndrome) and excessive daytime sleepiness (EDS) than typically developing children. The aim of this article is to propose a narrative review of the assessment of EDS in the context of ADHD with first a summary of the subjective and objective tools used to measure it. Secondly, perspectives in terms of electroencephalogram (EEG) markers and neurofeedback are proposed. Then, possibilities for new kinds of evaluation are discussed (virtual reality, ecological momentary assessment, etc.). Lastly, we discuss specific clinical situations with EDS in the context of ADHD as links with narcolepsy, the comorbidity with other psychiatric disorders, and the context of sluggish cognitive tempo.

Factor structure of the Sleep Disturbance Scale for Children (SDSC) in those with Attention Deficit and Hyperactivity Disorder (ADHD)

Objective

Method

Results

Conclusion

•

The original SDSC factor structure could not be replicated in an ADHD sample.

•

The fit of competing factor structures was evaluated.

•

An optimal structure including six-specific and a general factor was identified.

•

The alternative structure reported adequate psychometric properties.

•

The SDSC may be used to yield a total sleep difficulties score in ADHD samples.

Co-Sleeping among School-Aged Anxious and Non-Anxious Children: Associations with Sleep Variability and Timing

Little is known about the co-sleeping behaviors of school-aged children, particularly among anxious youth who commonly present for the treatment of sleep problems. The current study examined the occurrence of co-sleeping in both healthy and clinically anxious children and its associated sleep patterns. A total of 113 children (ages 6-12), 75 with primary generalized anxiety disorder and 38 healthy controls, participated along with their primary caregiver. Families completed structured diagnostic assessments, and parents reported on their child's co-sleeping behaviors and anxiety severity. Children provided reports of anxiety severity and completed one week of wrist-based actigraphy to assess objective sleep patterns. A significantly greater proportion of anxious youth compared to healthy children co-slept, and greater anxiety severity was related to more frequent co-sleeping. Co-sleeping in anxious youth was associated with a delay in sleep timing and with greater sleep variability (i.e., more variable nightly sleep duration). All analyses controlled for child age, race/ethnicity, family income, and parental marital status. Co-sleeping is highly common in anxious school-aged children, with more than 1 in 3 found to co-sleep at least sometimes (2-4 times a week). Co-sleeping was even more common for youth with greater anxiety severity. Increased dependence on others to initiate and maintain sleep may contribute to poorer sleep in this population via shifted schedules and more variable sleep patterns.

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.

Listening to the Patient Voice in Narcolepsy: Diagnostic Delay, Disease Burden, and Treatment Efficacy

STUDY OBJECTIVES

Describe common symptoms, comorbidities, functional limitations, and treatment responsiveness among patients with narcolepsy. Investigate the effect of pediatric onset of narcolepsy symptoms on time to diagnosis of narcolepsy and presence of comorbid depression.

METHODS

Cross-sectional survey of 1,699 people in the United States with self-reported diagnosis of narcolepsy. We utilized mixed-methods data analyses to report study findings.

RESULTS

Most participants reported receiving a diagnosis of narcolepsy more than 1 y after symptom onset. We found that the strongest predictor of this delayed diagnosis was pediatric onset of symptoms (odds ratio = 2.4, p < 0.0005). Depression was the most common comorbidity but we detected no association with pediatric onset of narcolepsy symptoms. Overall, participants reported that fatigue and cognitive difficulties were their most burdensome symptoms in addition to sleepiness and cataplexy. The majority of participants reported residual daytime fatigue and/or sleepiness despite treatment. Most participants reported they could not perform at work or school as well as they would like because of narcolepsy symptoms.

CONCLUSIONS

This study provides unique insight into the narcolepsy disease experience. The study quantifies the problem of diagnostic delay for narcolepsy patients in the United States and highlights that symptoms are more likely to be missed if they develop before 18 y of age. These results suggest that narcolepsy awareness efforts should be aimed at parents, pediatric health care providers, school professionals, and children/adolescents themselves. Disease burden is high because of problems with fatigue, cognition, and persistence of residual symptoms despite treatment.

Assessment of Wakefulness and Brain Arousal Regulation in Psychiatric Research

During the last few decades, much knowledge has been gained about sleep being a heterogeneous condition with several distinct sleep stages that represent fundamentally different physiological states. The same applies for the wake state which also comprises distinct global functional states (called vigilance stages). However, various terms and concepts have been introduced describing different aspects of wakefulness, and accordingly several methods of assessment exist, e.g. sleep laboratory assessments (Multiple Sleep Latency Test, Maintenance of Wakefulness Test), questionnaires (Epworth Sleepiness Scale, Karolinska Sleepiness Scale), behavioural tasks (Psychomotor Vigilance Test) or electroencephalography (EEG)-based assessments (Alpha Attenuation Test, Karolinska Drowsiness Test). Furthermore, several theoretical concepts about the regulation of sleep and wakefulness have been put forward, and physiological correlates have been identified. Most relevant for healthy functioning is the regulation of brain arousal and the adaption of wakefulness to the environmental and situational needs so that the optimal balance between energy conservation and responsiveness can be obtained. Since one approach to the assessment of brain arousal regulation is the classification of EEG vigilance stages, a computer-based algorithm (Vigilance Algorithm Leipzig) has been introduced, allowing classification of EEG vigilance stages in EEG recordings under resting conditions. The time course of EEG vigilance stages in EEGs of 15-20 min duration allows estimation of the individual arousal regulation (hyperstable, adaptive, or unstable vigilance pattern). The vigilance model of affective disorders and attention-deficit/hyperactivity disorder links a disturbed arousal regulation to the pathogenesis of psychiatric disorders and accordingly helps to explain and possibly also predict treatment effects of pharmacological and non-pharmacological interventions for these conditions.

Attention Deficit Hyperactivity Disorder Symptoms, Sleepiness and Accidental Risk in 36140 Regularly Registered Highway Drivers

BACKGROUND

Attention Deficit Hyperactivity Disorder (ADHD) is a frequent neurodevelopmental disorder that increases accidental risk. Recent studies show that some patients with ADHD can also suffer from excessive daytime sleepiness but there are no data assessing the role of sleepiness in road safety in patients with ADHD. We conducted an epidemiological study to explore sleep complaints, inattention and driving risks among automobile drivers.

METHODS AND FINDINGS

From August to September 2014, 491186 regular highway users were invited to participate in an Internet survey on driving habits. 36140 drivers answered a questionnaire exploring driving risks, sleep complaints, sleepiness at the wheel, ADHD symptoms (Adult ADHD Self-Report Scale) and distraction at the wheel. 1.7% of all drivers reported inattention-related driving accidents and 0.3% sleep-related driving accidents in the previous year. 1543 drivers (4.3%) reported ADHD symptoms and were more likely to report accidents than drivers without ADHD symptoms (adjusted OR = 1.24, [1.03-1.51], p < .021). 14.2% of drivers with ADHD symptoms reported severe excessive daytime sleepiness (Epworth Sleepiness Scale >15) versus 3.2% of drivers without ADHD symptoms and 20.5% reported severe sleepiness at the wheel versus 7.3%. Drivers with ADHD symptoms reported significantly more sleep-related (adjusted OR = 1.4, [1.21-1.60], p < .0001) and inattention-related (adjusted OR = 1.9, [1.71-2.14], p<0001) near misses than drivers without ADHD symptoms. The fraction of near-misses attributable to severe sleepiness at the wheel was 4.24% for drivers without ADHD symptoms versus 10,35% for drivers with ADHD symptoms.

CONCLUSION

Our study shows that drivers with ADHD symptoms have more accidents and a higher level of sleepiness at the wheel than drivers without ADHD symptoms. Drivers with ADHD symptoms report more sleep-related and inattention-related near misses, thus confirming the clinical importance of exploring both attentional deficits and sleepiness at the wheel in these drivers. Road safety campaigns should be improved to better inform drivers of these accidental risks.

Excessive daytime sleepiness in patients with ADHD--diagnostic and management strategies

The links between attention-deficit hyperactivity disorder (ADHD) and sleep disorders remain unclear. Specific sleep disorders are a frequent comorbid condition associated with ADHD according to a categorical approach. However, sleep disorders can also induce ADHD-like symptoms according to a dimensional approach and are thought to be the consequence of excessive daytime sleepiness. It may thus be difficult for clinicians to differentiate the diagnosis of ADHD comorbid with a sleep disorder from sleep disorders with ADHD-like symptoms. This distinction could be important for the appropriate management of patients with dual complaints of trouble maintaining attention and daytime sleepiness. This paper summarizes the main sleep disorders associated with ADHD: sleep-related breathing disorders, sleep-related movement disorders, circadian rhythm sleep-wake disorders, and central disorders of hypersomnolence (aka hypersomnias). The history of presenting symptoms should be taken into account since ADHD is a neurodevelopmental disorder whereas ADHD symptoms comorbid with sleep disorder are not. Finally, we propose a model to clarify the links between ADHD, ADHD symptoms, and excessive daytime sleepiness induced by sleep disorders. Clinicians should therefore routinely assess, monitor, and manage the sleep problems of patients with ADHD who have both comorbidities and should search for the presence of ADHD symptoms in subjects with sleep disorders.

Attention-deficit/hyperactivity disorder and obesity in US males and females, age 8-15 years: National Health and Nutrition Examination Survey 2001-2004

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Youth with ADHD may be at increased risk for obesity. Medications used to treat ADHD can affect weight. Few studies have investigated possible gender differences in associations between ADHD and obesity.

WHAT THIS STUDY ADDS

Nationally representative of US youth aged 8-15 years. Height and weight were measured, and ADHD assessed by structured diagnostic interview and parent report. Associations between ADHD and obesity are reported for males and females to enable gender comparisons.

OBJECTIVE

To investigate how associations between attention-deficit/hyperactivity disorder (ADHD) and obesity differ by gender and medication use in a nationally representative sample of US youth in which height and weight were measured.

METHODS

Youth age 8-15 (n = 3050) studied in the National Health and Nutrition Examination Survey 2001-2004. Obesity was defined as ≥95th percentile of US body mass index-for-age reference. ADHD was determined by asking parents if child had been diagnosed and using the Diagnostic Interview Schedule for Children IV. Gender-stratified multivariable logistic regression was used to estimate odds of obesity for youth with ADHD (medicated and unmedicated) relative to youth without ADHD.

RESULTS

Males with ADHD who were medicated had lower odds of obesity compared to males without ADHD (adjusted odds ratio [OR] = 0.42, 95% confidence interval [CI] = 0.23-0.78). Unmedicated males with ADHD were as likely as males without ADHD to be obese (adjusted OR = 1.02, 95% CI = 0.43-2.42). The odds of obesity for females taking medication for ADHD did not differ statistically from those of females without ADHD (adjusted OR = 1.21, 95% CI = 0.52-2.81). Females with ADHD not taking medication had odds of obesity 1.54 times those of females without ADHD; however, the 95% CI (0.79-2.98) was wide and not statistically significant at α = 0.05.

CONCLUSIONS

Associations between ADHD and obesity are influenced by treatment of ADHD with medication and may differ by gender. Youth with ADHD who are not treated with medication are as or more likely than youth without ADHD to be obese.

Relationship between polysomnographic sleep architecture and behavior in medication-free children with TS, ADHD, TS and ADHD, and controls

OBJECTIVE

To describe the relationship between sleep architecture and behavioral measures in unmedicated children and adolescents with Tourette syndrome (TS), attention-deficit hyperactivity disorder (ADHD), TS and comorbid ADHD (TS + ADHD), and healthy controls. The study also set out to examine differences in sleep architecture with each diagnosis.

METHOD

A cross-sectional, 2-night consecutive polysomnographic sleep study was conducted in 90 children. All participants were matched for age, gender, and level of intelligence.

RESULTS

Scores on the Child Behavior Checklist delinquency measure were modestly but significantly correlated with the number of movements during REM sleep (r = .36, p = .003). Significant correlations were also noted among the number of total arousals and arousals from slow wave sleep (SWS), and scores on the measures of conduct disorder, hyperactivity/immaturity, and restless/disorganized behaviors. There were a few significant differences in sleep architecture among the diagnostic groups. The ADHD-only group exhibited a significantly higher number of total arousals (p < .01) and arousals from SWS (p < .01) compared with the other three study groups.

DISCUSSION

Our findings indicate that children with TS and/or ADHD and who have more arousals from sleep are significantly more likely to have issues with conduct disorder, hyperactivity/immaturity, and restless/disorganized behavior. It was also noted that having ADHD, alone or comorbid with TS, is associated with a significantly greater number of movements during both non-REM and REM sleep. This study underscores the compelling need for the diagnosis and treatment of any sleep disorders in children with TS and/or ADHD so as to facilitate better management of problem behaviors.

A retrospective survey of childhood ADHD symptomatology among adult narcoleptics

OBJECTIVE

This study examined the retrospective history of childhood ADHD symptomatology in an adult narcoleptic population (Narcolepsy Group [NG]: n = 161) compared with a control group (CG: n = 117).

METHOD

Both groups completed the Wender Utah Rating Scale (WURS), a retrospective self-report questionnaire indicating the presence of childhood ADHD symptomatology in adults.

RESULTS

Childhood ADHD symptoms were significantly greater in NG than CG (p < .001). Joint prevalence calculations of childhood ADHD symptomatology in NG were more than 8 to 15 times greater than expected. Among NG, those individuals with a greater score on the WURS, indicative of childhood ADHD symptomatology, also had shorter sleep onsets on the Multiple Sleep Latency Test, a common objective measure of sleepiness, t(97) = -7.11, p < .05.

CONCLUSION

It appears that self-reported childhood ADHD symptomatology history among adult narcoleptics is common. Future research is warranted with adult narcoleptics to elucidate the true nature of this.

Motor regulation problems and pain in adults diagnosed with ADHD

Background

Most children who are diagnosed with attention deficit-hyperactivity disorder (ADHD) have moderate-to-severe motor problems using the Motor Function Neurological Assessment battery (MFNU). The MFNU focuses on specific muscle adjustment problems associated with ADHD, especially motor inhibition problems and high muscle tone. Here we investigated whether adults with ADHD/hyperkinetic disorder (HKD) have similar motor problems. In our clinical experience, adults with ADHD often complain about back, shoulder, hip, and leg pain. We also investigate reported pain in adults with ADHD.

Methods

Twenty-five adult outpatients diagnosed with ADHD/HKD who were responders to methylphenidate (MPH) were compared to 23 non-ADHD controls on 16 MFNU subtests and using a ‘total score’ (‘TS’) parameter. The MFNU test leader was blinded to group identity. The two groups were also compared using the Pain Drawing and Numerical Pain Rating Scale.

Results

The adult ADHD group had significantly (p < .001) more motor problems (higher TS) than controls. On the muscle regulation subtests, 36–96% of the ADHD group showed ‘moderate’ to ‘severe’ problems compared to 13–52% of the control group, and 80% of the ADHD group reported widespread pain. Highly significant differences were found between the ADHD and control groups for the variables ‘pain level’ (p < .001) and ‘pain location’ (p < .001). Significant correlations were found between TS and ‘pain location’ and between TS and ‘pain level’.

Conclusions

These findings suggest that similar to children with ADHD, adults diagnosed with ADHD also have motor inhibition problems and heightened muscle tone. The presence of significantly higher pain levels and more widespread pain in the ADHD group compared to non-ADHD controls might indicate that pain is a long-term secondary effect of heightened muscle tone and restricted movement that can be demonstrated in children and adults by the MFNU battery.

Prevalence of allergic rhinitis in patients with attention-deficit/hyperactivity disorder: a population-based study

Allergic rhinitis (AR) is common in children. Characteristic symptoms of AR may result in daytime inattention, irritability, and hyperactivity, which are also components of ADHD. Conflicting data in previous studies exist regarding the relationship between ADHD and AR. The aim of this study was to examine the prevalence and risk of AR in ADHD patients in Taiwan. We conducted a cross-sectional study using the National Health Insurance Research Database in Taiwan. The study subjects included 469 patients who received psychiatric care for ADHD in 2005 and the general population (n = 220,599). Distributions of age, gender, and living areas as well as allergic diseases in the general population and in the ADHD group were examined by χ2 tests. Multivariate logistic regression models were used to analyze the risk factors of AR. The prevalence of AR in ADHD group and the general population was 28.4 and 15.2%, respectively. The prevalence of asthma was 9.6% in ADHD group and 6.4% in the general population. Both the prevalence of AR (p < 0.001) and asthma (p = 0.008) was significantly higher in ADHD group than the general population. The multivariate logistic regression analysis showed that ADHD patients had an increased rate of AR than general population (OR = 1.83; 95% CI = 1.48-2.27; p < 0.0001), and asthma was strongly associated with AR (OR = 9.28; 95% CI = 8.95-9.63; p < 0.0001). Our data showed that ADHD patients had an increased rate of AR. Therefore, psychiatrists should be more aware of the comorbidity of AR when treating ADHD patients.

Sensory and sensorimotor gating in adult attention-deficit/hyperactivity disorder (ADHD)

Even though there is an impaired perceptual capacity in attention-deficit/hyperactivity disorder (ADHD) patients, psychophysiological alterations, such as impaired gating as indexed by prepulse inhibition (PPI) or suppression of P50 auditory event-related potentials, have not been found in patients with ADHD. Hence, potential relationships of psychophysiological measures of gating to psychopathology and cognitive performance remain unclear. The present study investigates two distinct operational measures of gating as well as cognitive performance within adult ADHD patients in order to assess the relationship of these measures to psychopathology. PPI, P50 suppression, cognitive performance, and psychopathologic symptoms were assessed in 26 ADHD patients and 26 healthy control subjects. ADHD patients compared to healthy control subjects exhibited impaired P50 suppression, performed worse in cognitive tasks, and reported more psychopathological symptoms, but were normal in the test of PPI. Thus, P50 gating deficits are not specific to schizophrenia-spectrum disorders. These findings highlight the differences between P50 gating and PPI as measures of the gating construct. In keeping with the lack of correlations between these two putative operational measures of gating seen in both humans and animals, adult ADHD patients exhibit deficient P50 suppression and poor cognitive performance, despite exhibiting normal levels of PPI.

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.

Prevalence of attention-deficit/hyperactivity disorder in patients with pediatric allergic disorders: a nationwide, population-based study

BACKGROUND

Allergic disorders are common, chronic conditions in pediatric populations. The characteristic symptoms of allergic disorders mainly include bronchial asthma (BA), allergic rhinitis (AR), and atopic dermatitis (AD), all of which may disturb sleep, leading to daytime inattention, irritability, and hyperactivity, which are also components of attention-deficit/hyperactivity disorder (ADHD). Conflicting data exist in the literature regarding the relationship between ADHD and allergic disorders. The aim of this nationwide, population-based study is to examine the prevalence and risk of developing ADHD among allergic patients in a pediatric group.

METHODS

Data from a total of 226,550 pediatric patients under 18 years of age were collected from Taiwan's National Health Insurance Research Database recorded from January 1 to December 31, 2005 and analyzed. We calculated the prevalence of allergic diseases based on various demographic variables, including ADHD. We also used multivariable logistic regression to analyze the risk factors of ADHD.

RESULTS

In 2005, the period prevalence rates of allergic disorders and ADHD in persons under the age of 18 were 21.5% and 0.6%, respectively. Pediatric patients with allergic disorder(s) had a substantially increased rate of developing ADHD (p < 0.001) in terms of period prevalence and odds ratio (OR). This significance existed across various demographic groups regardless of age, gender, location, or degree of urbanization of their residence. BA and AR, but not AD, were determined to be risk factors for ADHD. Co-morbidities of allergic disorders, including AR+AD, AR+BA and AR+BA+AD, but not BA+AD, were also determined to increase the risk of ADHD.

CONCLUSION

Allergic disorders appear to increase the risk of ADHD in pediatric patients. Our detailed analysis shows that the main contributing factor is AR. Co-morbidity with AD, BA, and BA+AD in AR patients further increases the risk of ADHD.

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.

Prevalence, correlates, and comorbidities of adult ADHD symptoms in Korea: results of the Korean epidemiologic catchment area study

We examined the prevalence, correlates, and comorbidities of adult attention-deficit hypersensitivity disorder (ADHD) symptoms in a Korean community using data from the National Epidemiological Survey of Psychiatric Disorders in Korea conducted in 2006. A total of 6081 subjects aged 18 to 59 years participated in this study. Diagnostic assessments were based on the Adult ADHD Self-Report Scale Screener and Composite International Diagnostic Interview administered by lay interviewers. The frequencies of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) disorders, sleep disturbances, and suicidal tendency were compared in the ADHD and non-ADHD groups. Odds ratios and significance levels were calculated. The 6 month prevalence of adult ADHD symptoms was 1.1%. Associations between ADHD symptoms and alcohol abuse/dependence, nicotine dependence, mood disorders, major depressive disorder, bipolar disorder, anxiety disorders, obsessive-compulsive disorder, post-traumatic stress disorder, social phobia, specific phobia, somatoform disorder, sleep disturbances, and suicidality were overwhelmingly positive and significant (P<0.05), after controlling for gender and age. Adult ADHD symptoms are highly associated with substance abuse, mood and anxiety disorders, somatoform disorders, sleep disturbances and suicidality, suggesting that clinicians should carefully evaluate and treat such psychiatric disorders in adults with ADHD symptoms.

European guidelines on managing adverse effects of medication for ADHD

The safety of ADHD medications is not fully known. Concerns have arisen about both a lack of contemporary-standard information about medications first licensed several decades ago, and signals of possible harm arising from more recently developed medications. These relate to both relatively minor adverse effects and extremely serious issues such as sudden cardiac death and suicidality. A guidelines group of the European Network for Hyperkinetic Disorders (EUNETHYDIS) has therefore reviewed the literature, recruited renowned clinical subspecialists and consulted as a group to examine these concerns. Some of the effects examined appeared to be minimal in impact or difficult to distinguish from risk to untreated populations. However, several areas require further study to allow a more precise understanding of these risks.

Associations among sleep problems, learning difficulties and substance use in adolescence

This study investigated the relationships among sleep problems, learning difficulties and substance use in adolescence. Previous research suggests that these variables share an association with executive functioning deficits, and are intertwined. The sample comprised 427 adolescents (M age = 16 years) attending remedial schools and 276 adolescents (M age = 15 years) attending a mainstream school in Cape Town, South Africa. Participants completed anonymous self-report questionnaires. Results indicated that adolescents without learning difficulties were more likely to use tobacco, methamphetamine and cannabis, whereas those with learning difficulties engaged in more inhalant use. Adolescents who had more sleep problems were more likely to use tobacco, alcohol, methamphetamine, cannabis, inhalants, cocaine, ecstasy and any other illegal drug. Adolescents with learning difficulties had more sleep problems than those without learning difficulties. However, sleep problems remained independently associated with tobacco, cannabis and inhalant use when learning difficulties were taken into account.

Serotonergic neurotransmission and lapses of attention in children and adolescents with attention deficit hyperactivity disorder: availability of tryptophan influences attentional performance

Deficiencies in serotonergic (5-HT) neurotransmission have frequently been linked to altered attention and memory processes. With attention deficit hyperactivity disorder (ADHD) being associated with impaired attention and working memory, this study investigated the effects of a diminished 5-HT turnover achieved by rapid tryptophan depletion (RTD) on attentional performance in children and adolescents with ADHD. Twenty-two male patients with ADHD (aged 9-15 yr) received the RTD procedure Moja-De and a tryptophan (Trp)-balanced placebo (Pla) in a randomized, double-blind, within-subject crossover design on two separate study days. Lapses of attention (LA) and phasic alertness (PA) were assessed within the test battery for attentional performance under depleted and sham-depleted conditions 120 (T1), 220 (T2) and 300 (T3) min after intake of RTD/Pla. At T1 there was a significant main effect for RTD, indicating more LA under intake of a Trp-balanced Pla compared to diminished 5-HT neurotransmission. For T2/T3 there were no such effects. PA was not affected by the factors RTD/Pla and time. Interactions of 5-HT with other neurotransmitters as possible underlying neurochemical processes could be subject to further investigations involving healthy controls as regards altered attentional performance in children and adolescents.

College students with attention-deficit/hyperactivity disorder

As more students with attention-deficit/hyperactivity disorder attend college, studies are emerging that reveal problems in psychosocial and academic functioning. Substance use may magnify deficits in self-regulation. Recommendations are made for comprehensive assessment; however, the usual diagnostic categories may not be developmentally relevant. Students who are identified benefit from medication and nonmedication interventions, strategy support, and accommodations.

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.

Parent-reported attention-deficit/hyperactivity disorder symptomatology and sleep problems in a preschool-age pediatric clinic sample

OBJECTIVE

To examine the association between attention-deficit/hyperactivity disorder symptomatology and parent-reported sleep problems among preschoolers ages 2 to 5 years.

METHOD

A total of 1,073 parents of preschoolers ages 2 to 5 years attending a large pediatric clinic completed the Child Behavior Checklist 1(1/2)-5 years. A stratified probability sample of 193 parents of high scorers and 114 parents of low scorers were interviewed with the Preschool Age Psychiatric Assessment. Poisson regression was used to test the association between parent-reported sleep problems and attention-deficit/hyperactivity disorder symptomatology, as well as psychiatric and demographic covariates.

RESULTS

When considered without reference to other psychiatric disorders, elevated hyperactive-impulsive symptomatology was positively associated with parent reported problems including sleep assistance, parasomnias, and dyssomnias; however, all of these effects were attenuated to nonsignificance once psychiatric comorbidity was controlled. In contrast, elevated inattentive symptomatology (especially at lower levels of hyperactive-impulsive symptoms) was positively associated with daytime sleepiness even after psychiatric comorbidity was controlled.

CONCLUSIONS

Neither hyperactive-impulsive nor inattentive attention-deficit/hyperactivity disorder symptomatology was uniquely related to parent-reported problems involving sleep assistance, parasomnias, or dyssomnias. However, inattentive symptomatology was uniquely related to daytime sleepiness above and beyond commonly occurring patterns of psychiatric comorbidity, sleep duration, and demographic factors.

Sleep Disturbances in Singaporean Children with Attention Deficit Hyperactivity Disorder

Introduction: Many studies have reported various levels of association between sleep disorders and attention deficit hyperactivity disorder (ADHD). This study aims to investigate sleep disturbances in children with ADHD prior to treatment and during treatment. Materials and Methods: This study recruited 114 child and adolescent patients diagnosed with ADHD and 60 normal patients. Sleep disturbances are assessed using the parent-rated Child Behaviour Checklist (CBCL) questionnaire. In addition, chart reviews and semi-structured clinical interviews were conducted for 54 patients with ADHD who had been seen at the clinic since 2002 to examine the sleep disturbances they experienced during treatment over a 4-year period. Results: Compared to the normal subjects, parents of children with ADHD reported that their children slept less. The summation score of the sleep items on the CBCL was also significantly higher in the ADHD group. Girls with ADHD also had more “trouble sleeping”. When children with ADHD received treatment with medications, they experienced sleep-related side effects. Out of the 54 children with ADHD, 18.5% experienced sleep disturbance related to medication, with 13.0% reporting daytime somnolence and 5.5% reporting insomnia. Conclusion: Our study showed that there was an increased frequency of sleep disturbances in children with ADHD prior to treatment with medications. The children in our study appeared to sleep less. A significant proportion also experienced sleep disturbance during treatment with medication, of which daytime somnolence and insomnia were the most commonly reported problems. Future research in this area is needed to further examine the range of sleep disorders in ADHD children locally. Key words: Child Behaviour Checklist, Insomnia, Methylphenidate

Chronic nicotine exposure has dissociable behavioural effects on control and beta2-/- mice

Nicotine exerts beneficial effects on various neurological and psychiatric pathologies, yet its effects on cognitive performance remain unclear. Mice lacking the beta2 subunit of the nicotinic receptor (beta2-/-) show characteristic deficits in executive functions and are suggested as reliable animal models for some specific endophenotypes of human pathologies, notably ADHD. We use beta2-/- and their controls to investigate the consequences of chronic nicotine exposure on cognitive behaviour. We show that in control mice, this treatment elicits somewhat slight effects, particularly affecting nocturnal activity and self-grooming. By contrast, in beta2-/- mice, chronic nicotine treatment had restorative effects on exploratory behaviour in the open-field and affected rearing, but did not modify motor functions. We confirmed that beta2-/- mice exhibit impaired exploratory and social behaviour, and further demonstrated their nocturnal hyperactivity. These data support the proposal that beta2-/- mice represent a relevant model for cognitive disorders in humans and that nicotine administered chronically at low dose may relieve some of these.

ADHD from a socio-economic perspective

AIM

Attention deficit hyperactivity disorder (ADHD) and related disorders affect children's ability to function in school and other environments. Awareness has increased in recent years that the same problems often persist in adulthood. Based on previous studies, we aimed to outline and discuss a descriptive model for calculation of the societal costs associated with ADHD and related disorders.

METHODS

Following a literature review including childhood and adult studies, long-term outcomes of ADHD and associated societal costs were outlined in a simple model.

RESULTS

The literature concerning long-term consequences of ADHD and related disorders is scarce. There is some evidence regarding educational level, psychosocial problems, substance abuse, psychiatric problems and risky behaviour. The problems are likely to affect employment status, healthcare consumption, traffic and other accidents and criminality. A proposed model structure includes persisting problems in adulthood, possible undesirable outcomes (and their probabilities) and (lifetime) costs associated with these outcomes.

CONCLUSIONS

Existing literature supports the conclusion that ADHD and related disorders are associated with a considerable societal burden. To estimate that burden with any accuracy, more detailed long-term data are needed.

Sleep problems associated with ADHD: a review of current therapeutic options and recommendations for the future

In recent years, there has been a growing interest in sleep problems associated with attention-deficit/hyperactivity disorder (ADHD). The etiology of these sleep problems is multifactorial. In this paper, we review the current literature on the treatment of the most common disorders or factors underlying sleep problems associated with ADHD. In particular, we focus on the management of sleep problems associated with ADHD medications, restless legs syndrome, excessive nocturnal motricity in sleep, sleep disordered breathing, sleep-onset insomnia and psychiatric comorbidities associated with ADHD. Given the paucity of randomized, controlled, double-blinded, placebo-controlled studies, it is hoped that this review will encourage further methodologically sound studies in order to be able to develop treatment guidelines.

Seasonality and circadian preference in adult attention-deficit/hyperactivity disorder: clinical and neuropsychological correlates

OBJECTIVE

The objective of the study was to measure both seasonal mood change and circadian preference, and their clinical and neuropsychological correlates, in adults with ADHD during the fall/winter months.

METHOD

Twenty-nine adults with attention-deficit/hyperactivity disorder (ADHD) were assessed in the fall/winter season using self-report measures of ADHD, mood, seasonality, and circadian preference. Neuropsychological tests were also completed. Correlations between chronobiologic variables and clinical/neuropsychological measures were performed.

RESULTS

Consistent with prior work in adult ADHD, high rates of seasonal depression were reported in this sample. Based on the morningness-eveningness questionnaire, which assesses circadian preference 11 (40.7%, N = 27) subjects were designated as evening types and only 5 (18.5%) as morning types, a distribution highly discrepant with general population studies. Later circadian preference, independent of seasonality, was strongly correlated with both self-reported symptoms of ADHD and neuropsychological deficits, including impulsive responding and poor target discrimination. None of these findings was attributable to state depression.

CONCLUSIONS

In the fall/winter period, a mood-independent delay in circadian phase may contribute significantly to core pathology in many adults with ADHD. These findings establish a potential target for chronobiologic treatments such as light therapy in this complex population.

Sleep patterns in children with attention-deficit/hyperactivity disorder, tic disorder, and comorbidity

BACKGROUND

In children, attention-deficit/hyperactivity disorder (ADHD), tic disorder (TD), and their coexistence (ADHD + TD comorbidity) are very common and clinically important. Associated sleep patterns and their clinical role are still insufficiently investigated. This study aimed at characterizing these sleep patterns in children with ADHD, TD, and ADHD + TD comorbidity and determining whether, in ADHD + TD, the factors ADHD and TD may affect the sleep pattern in an independent (additive) or in a complex (interactive) manner.

METHOD

By means of polysomnography, sleep patterns were investigated in 4 groups of unmedicated 8.0-16.4-year-old children (healthy controls, ADHD-only, TD-only, and ADHD + TD). Each group consisted of 18 subjects matched for age, gender, and intelligence.

RESULTS

ADHD was primarily characterized by increase in rapid eye movement (REM) sleep, whereas TD patients displayed lower sleep efficiency and elevated arousal index in sleep. In children with ADHD + TD, both effects appeared. No interaction between the ADHD and TD factors was found for any of the sleep parameters. Significant correlations between sleep patterns and clinical symptoms were found.

CONCLUSIONS

ADHD and TD are characterized by specific sleep alterations. When coexisting, the two disorders alter the sleep pattern in an additive manner, suggesting a high impact on clinical and therapeutic perspectives.

Special considerations in diagnosing and treating attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent chronic condition that affects people of all ages, including young children, school-aged children, adolescents, and adults. Symptoms can be noted as early as preschool age, tend to progress into functional impairment and behavioral problems in later childhood, and typically persist into adulthood. Contrary to previous belief, the disorder does not resolve with puberty for the majority of children; rather, the symptoms are manifested differently throughout the lifecycle. Presentation in adults is heavily biased toward inattentive symptoms, which are less likely to draw notice than hyperactive or impulsive symptoms and may contribute to the underrecognition of ADHD in this patient population. Diagnosis is particularly difficult due in large part to the pronounced comorbidity of psychiatric disorders in this patient population. Identification may be even more difficult in adults than children as the diagnostic criteria are not as clear, adults have difficulty remembering symptoms prior to 7 years of age, and there is a high prevalence of comorbid psychiatric disorders in adults. Early identification and treatment of symptoms of ADHD in preschool-age children is essential to effective long-term management of the disorder. Both medication and behavioral treatments appear to alleviate the symptoms of ADHD, and evidence suggests that discontinuation of treatment leads to the reemergence of the condition. Efforts are currently continuing toward understanding the genetic underpinnings of ADHD. This expert review supplement will address the prevalence, comorbidity, treatment issues, and special considerations surrounding ADHD management throughout each stage of the lifecycle beginning with ADHD in preschool-aged children, continuing with school-aged children and adolescents, and ending with adulthood.

REM-sleep alterations in children with co-existence of tic disorders and attention-deficit/hyperactivity disorder: impact of hypermotor symptoms

PURPOSE

To characterize precisely the sleep pattern in children with co-existence of TD + ADHD.

METHODS

By means of polysomnography, sleep pattern was investigated in 19 children with TD + ADHD unmedicated before and during study and 19 healthy controls, matched for age, gender, and intelligence.

RESULTS

Compared with healthy controls, children with TD + ADHD displayed shorter REM sleep latency and increased REM sleep duration. There was a negative correlational relationship between these REM-sleep alterations and they were determined by hyperactivity symptoms.

CONCLUSIONS

Sleep in children with coexistence of TD + ADHD may be characterized by an elevated REM sleep drive. Common mechanisms are suggested to underpin hypermotor symptoms and REM sleep regulation.

Sleep disturbance and its relation to DSM-IV psychiatric symptoms in preschool-age children with pervasive developmental disorder and community controls

This study describes the relation between sleep problems and psychiatric symptoms in preschool-age children (3 to 5 years old) with pervasive developmental disorder and a community-based sample of children attending early childhood programs. Parents completed the Early Childhood Inventory-4, a Diagnostic and Statistical Manual of Mental Disorders (fourth edition)-referenced rating scale for 2 samples: children with pervasive developmental disorder (n = 112) and nondisabled youngsters (n = 497). Although children with pervasive developmental disorder had a significantly greater number and severity of sleep problems than the community preschoolers did, sleep-disturbed children in both samples exhibited more severe behavioral difficulties-primarily symptoms of attention-deficit hyperactivity disorder and oppositional defiant disorder-than did children without sleep problems. Sleep problems are an indicator of similar comorbid psychiatric symptoms in both children with and without pervasive developmental disorder, which suggests commonalities in their etiology.

A murine model of hyperdopaminergic state displays altered respiratory control

The dopamine transporter (DAT) protein plays an important role in the termination of dopamine signaling. We addressed the hypothesis that loss of DAT function would result in a distinctive cardiorespiratory phenotype due to the significant role of dopamine in the control of breathing, especially with respect to chemical control, metabolism, and thermoregulation. The DAT knockout mouse (DAT-/-) displays a state of functional hyperdopaminergia characterized by marked novelty driven hyperactivity. Certain behavioral and drug responses in these mice are reminiscent of endophenotypes of individuals with attention deficit hyperactivity disorders (ADHD). We performed experiments on conscious, unrestrained DAT-/- mice (KO) and littermate DAT+/+ wild-type (WT) controls. Ventilation was measured by the barometric technique during normoxia, hypoxia, or hypercapnia. We measured core body temperature and CO2 production as an index of metabolism. DAT-/- mice displayed a significantly lower respiratory frequency than WT mice, reflecting a prolonged inspiratory time. DAT-/- mice exhibited a reduced ventilatory response to hypoxia characterized by an attenuation of both the respiratory frequency and tidal volume responses. Both groups showed similar metabolic responses to hypoxia. Circadian measurements of body temperature were significantly lower in DAT-/- mice than WT mice during inactive periods. We conclude that loss of the DAT protein in this murine model of altered dopaminergic neurotransmission results in a significant respiratory and thermal phenotype that has possible implications for understanding of conditions associated with altered dopamine regulation.

Psychiatric comorbidity in adults with attention-deficit/hyperactivity disorder (ADHD)

Attention-deficit/hyperactivity disorder (ADHD) is a chronic, lifelong disorder with childhood-onset, which seriously impairs the affected adults in a variety of daily living functions like educational and occupational functioning, partnership and parenting. ADHD is associated with a high percentage of comorbid psychiatric disorders in every lifespan. In adulthood between 65-89% of all patients with ADHD suffer from one or more additional psychiatric disorders, above all mood and anxiety disorders, substance use disorders and personality disorders, which complicates the clinical picture in terms of diagnostics, treatment and outcome issues. The present overview provides information of comorbid psychiatric disorders in adults with ADHD, underlying associations and clinical implications.

Attention deficit disorders: are we barking up the wrong tree?

Attention deficit disorder (AAD) and attention deficit/hyperactivity disorder (ADHD) are very frequent and protean developmental disorders without a definite biologic marker. This review proposes a framework to understand the enlarged spectrum of its manifestations based on current knowledge of the mechanisms underlying arousal and attention variations during sleep/wake cycle. The neuro-modulation's pivotal role in this process as well as in the fine tuning of synaptic architecture during development must be taken into account when trying to understand the marked fuzziness of the symptoms and the very high prevalence of reported co-morbidities. The series of related interactions includes a cyclic deactivation of the dorso-lateral portion of the prefrontal cortex (DLPFC) during sleep, suspending executive functions, co-occurring with rhythmic periods of decreased noradrenergic tonus. A protracted unbalance in modulation, with catecholaminergic relative deficiency, could explain less-than-optimum waking DLPFC activation and the most important manifestations of ADD. Beside the well documented dopaminergic effects of stimulant medication used in ADD and ADHD, a more important role must be assigned to noradrenaline (NA). At this light hyperactivity and impulsivity are less important dimensions. Rather, an attention deficit spectrum disorder should probably be regarded as a complication of a core defect in prefrontal cortex dependent inhibitory control, underlying inattention.

The course of neuropsychological functions in children with attention deficit hyperactivity disorder from late childhood to early adolescence

OBJECTIVE

The aim of this follow-up study was to investigate the course of performance in attentional tasks in children with ADHD and normal controls in late childhood and preadolescence over short periods of time. The development of two dimensions of attention was compared: alertness/arousal and inhibitory control.

METHOD

Children with ADHD (N=28) and normal controls (N=25) were examined at three times: at baseline (age mean=10.8 years, SD=1.5), after one year (age mean=12.0 years, SD=1.6), and after 2.6 years (age mean=13.3 years, SD=1.6). They performed two tasks of a computerized battery for attentional performance: Alertness--a test of simple reaction time to visual stimuli contrasting a condition with and without auditory warning signal, and Incompatibility--a test of spatial interference/inhibitory control. Clinical diagnosis according to DSM-III-R criteria was established at time 1 and time 3 by structured diagnostic interviews.

RESULTS

In the Alertness task significant group differences regarding increased reaction time variability in ADHD, but not for reaction time itself, were found at time 1 and more pronounced at time 2. At time 3 group differences had disappeared. In the Incompatibility task group differences in number of errors were not observed at time 1, whereas children with ADHD made significantly more errors at time 2 and less pronounced at time 3. The degree of clinical symptom remission after 2.6 years was not related to changes in neuropsychological performance.

CONCLUSION

When measuring attentional functions, the selection of an appropriate time window seems to be essential for the detection of group differences between ADHD children and controls, because group differences are most pronounced before adolescence. The different developmental course of selective components of attention should be taken into account.

The ADHD and sleep conundrum: a review

The relationship between attention-deficit hyperactivity disorder (ADHD) and sleep is a complex one that poses many challenges in clinical practice. Recent studies have helped to elucidate the nature of the brain mechanisms and neuromodulator systems underlying the theoretical associations among sleepiness, arousal, and attention. Studies of sleep disturbances in children with academic and behavioral problems have also underscored the role that primary sleep disorders such as obstructive sleep apnea hypopnea syndrome play in the clinical presentation of symptoms of inattention and behavioral dysregulation. In addition, new methodologies used in examining sleep and sleep patterns in children diagnosed with ADHD have shed further light on the prevalence, type, risk factors for, and impact of sleep disturbances in these children. The following discussion of the multilevel relationships among sleep quality and quantity, neurobehavioral functioning, and the clinical syndrome of ADHD expands on previous reviews of the literature and synthesizes what is currently known about the interaction of sleep and attention/arousal in children to propose possible underlying mechanisms, integrate more recent findings, and highlight important areas for future study. In addition, guidelines are provided for a clinical approach to evaluation and management of children with ADHD and sleep problems.

Excessive sleepiness in adolescents and young adults: causes, consequences, and treatment strategies

Adolescents and young adults are often excessively sleepy. This excessive sleepiness can have a profound negative effect on school performance, cognitive function, and mood and has been associated with other serious consequences such as increased incidence of automobile crashes. In this article we review available scientific knowledge about normal sleep changes in adolescents (13-22 years of age), the factors associated with chronic insufficient sleep, the effect of insufficient sleep on a variety of systems and functions, and the primary sleep disorders or organic dysfunctions that, if untreated, can cause excessive daytime sleepiness in this population.