ADHD and female specific concerns: a review of the literature and clinical implications

Metal and essential element concentrations during pregnancy and associations with autism spectrum disorder and attention-deficit/hyperactivity disorder in children

BACKGROUND

Prenatal exposure to toxic metals or variations in maternal levels of essential elements during pregnancy may be a risk factor for neurodevelopmental disorders such as attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in offspring.

OBJECTIVES

We investigated whether maternal levels of toxic metals and essential elements measured in mid-pregnancy, individually and as mixtures, were associated with childhood diagnosis of ADHD or ASD.

METHODS

This study is based on the Norwegian Mother, Father and Child Cohort Study and included 705 ADHD cases, 397 ASD cases and 1034 controls. Cases were identified through linkage with the Norwegian Patient Registry. Maternal concentrations of 11 metals/elements were measured in blood at week 17 of gestation; cadmium; cesium; cobalt; copper; lead; magnesium; manganese; selenium; zinc; total arsenic; and total mercury. Multivariable adjusted logistic regression models were used to examine associations between quartile levels of individual metals/elements and outcomes. We also investigated non-linear associations using restricted cubic spline models. The joint effects of the metal/element mixture on ASD and ADHD diagnoses were estimated using a quantile-based g-computation approach.

RESULTS

For ASD, we identified positive associations (increased risks) in the second quartile of arsenic [OR = 1.77 (CI: 1.26, 2.49)] and the fourth quartiles of cadmium and manganese [OR = 1.57 (CI: 1.07 2.31); OR = 1.84 (CI: 1.30, 2.59)], respectively. In addition, there were negative associations between cesium, copper, mercury, and zinc and ASD. For ADHD, we found increased risk in the fourth quartiles of cadmium and magnesium [OR = 1.59 (CI: 1.15, 2.18); [OR = 1.42 (CI: 1.06, 1.91)]. There were also some negative associations, among others with mercury. In addition, we identified non-linear associations between ASD and arsenic, mercury, magnesium, and lead, and between ADHD and arsenic, copper, manganese, and mercury. There were no significant findings in the mixture approach analyses.

CONCLUSION

Results from the present study show several associations between levels of metals and elements during gestation and ASD and ADHD in children. The most notable ones involved arsenic, cadmium, copper, mercury, manganese, magnesium, and lead. Our results suggest that even population levels of these compounds may have negative impacts on neurodevelopment. As we observed mainly similarities among the metals' and elements' impact on ASD and ADHD, it could be that the two disorders share some neurochemical and neurodevelopmental pathways. The results warrant further investigation and replication, as well as studies of combined effects of metals/elements and mechanistic underpinnings.

Gender differences in externalizing and internalizing problems in Singaporean children and adolescents with attention-deficit/hyperactivity disorder

BACKGROUND

Studies on gender differences in attention-deficit/hyperactivity disorder (ADHD) comorbidities in the Asian populations have been limited and previous studies have shown inconclusive findings. Singapore is a city-state country in Southeast Asia with a population of 5.7 million. This study examined gender differences in internalizing and externalizing problems in Singaporean children and adolescents with ADHD. The plausible social factors underlying the gender differences were discussed.

METHODS

A total of 773 participants (aged 6 to 18, 88% males) newly diagnosed with ADHD were recruited from the largest public child and adolescent psychiatric center in Singapore. Their internalizing and externalizing problems were assessed using the Child Behavioral Checklist and Teacher's Report Form by parents and teachers respectively. Demographics and relevant social factors were collected using parent questionnaires.

RESULTS

Females with ADHD were reported to have less delinquent and aggressive behavior but more depressive symptoms than their male counterparts, similar to findings in the Western literature. Gender remained a significant predictor of externalizing problem after controlling for other factors. Lower socioeconomic status and parental use of physical punishment were significant predictors of both internalizing and externalizing problems.

CONCLUSIONS

Gender differences in ADHD comorbidities do exist in the Asian clinical population. The lack of externalizing symptoms in females with ADHD has made timely referral and diagnosis challenging. More research is needed in understanding the gender differences in ADHD and the biopsychosocial mechanism underlying the differences in order to improve the detection of ADHD in females.

Maternal Sociodemographic Factors Are Associated with Methylphenidate Initiation in Children in the Netherlands: A Population-Based Study

Multiple factors may contribute to the decision to initiate methylphenidate treatment in children such as maternal sociodemographic factors of which relatively little is known. The objective was to investigate the association between these factors and methylphenidate initiation. The study population included 4243 children from the Generation R Study in the Netherlands. Maternal sociodemographic characteristics were tested as determinants of methylphenidate initiation through a time-dependent Cox regression analysis. Subsequently, we stratified by mother-reported ADHD symptoms (present in 4.2% of the study population). When ADHD symptoms were absent, we found that girls (adjusted HR 0.25, 95%CI 0.16-0.39) and children born to a mother with a non-western ethnicity (compared to Dutch-Caucasian) (adjusted HR 0.42, 95%CI 015-0.68) were less likely to receive methylphenidate. They were more likely to receive methylphenidate when their mother completed a low (adjusted HR 2.29, 95%CI 1.10-4.77) or secondary (adjusted HR 1.71, 95%CI 1.16-2.54) education. In conclusion, boys and children born to a mother of Dutch-Caucasian ethnicity were more likely to receive methylphenidate, irrespective of the presence of ADHD symptoms.

Sex Differences in the Meaning of Parent and Teacher Ratings of ADHD Behaviors: An Observational Study

Objective: To test explanations for the underrecognition of female ADHD by examining differences in adult ratings of boys and girls matched for levels of directly observed ADHD behaviors. Method: In a secondary analysis of a population-based sample, 3- to 4-year-olds (n = 153, 79 male) and 8- to 9-year-olds (n = 144, 75 male) were grouped according to levels of directly observed ADHD behaviors (low/moderate/high). Groups were then compared with parent/teacher ADHD ratings. Results: There were no sex differences in levels of directly observed ADHD behaviors within groups. For preschoolers, parents' ratings of males, but not females, significantly increased across groups-mirroring levels of observed behaviors. For older children, both parent and teacher mean ratings were significantly higher for males than females across groups. Conclusion: Identified differences in adult ratings of males and females matched for directly observed behaviors may contribute to understanding the substantial ADHD underrecognition in females.

Gender differences in adult ADHD: Cognitive function assessed by the test of attentional performance

Introduction

The aim of this study was to assess cognitive differences between male and female adults with Attention Deficit Hyperactivity Disorder (ADHD).

Methods

Patients with an ADHD diagnosis according to the DSM-IV guidelines were included in a cross-sectional study evaluating cognitive measures. 28 women and 41 men from ages 19 to 56 completed self-report questionnaires and performed a computer-based test of attentional performance (TAP). The TAP assesses cognitive functions highly affected in ADHD patients, including working memory, alertness and attention as well as behavioral control and response inhibition.

Results

There were no measurable differences in self-report scales assessing current symptomology between the sexes, however men scored higher on the scale for childhood symptoms. Performance measures for general wakefulness were comparable between men and women, while working memory and behavioral control test results differed. Females reacted significantly slower and more unstable for both the TAP Go/NoGo paradigm and working memory subtest, while also making more errors in the latter.

Conclusions

We found gender-specific effects regarding working memory and behavioral control in this sample of adult patients with ADHD. Further studies are warranted, examining whether these differences relate to differences in clinical presentation and comorbidity patterns between men and women.

The effects of sex on prevalence and mechanisms underlying neurodevelopmental disorders

Neurodevelopmental disorders occur more frequently in boys than in girls and often differ in presentation between the sexes. The sex differences in prevalence and presentation of autism spectrum disorder, intellectual disability, communication disorders, specific learning disabilities, attention deficit/hyperactivity disorder, Tourette's syndrome, and epilepsy are discussed, as well as sex differences in the patterns of comorbidities between these disorders. Prominent theories have been proposed to explain sex biases. These include genetic factors, sex hormones, sociological factors, cognitive differences between the sexes, and environmental insult. Despite the large body of research reviewed in this chapter, many aspects of sex-related effects in neurodevelopmental disorders remain poorly understood.

The female side of pharmacotherapy for ADHD-A systematic literature review

OBJECTIVE

This comprehensive review examined sex differences in prescription rates and efficacy or effectiveness of pharmacotherapy treatment in girls and women with attention deficit hyperactivity disorder (ADHD), while identifying gaps in the scientific knowledge on this topic.

METHOD

A rigorous electronic database search was carried out in order to identify all published studies on female-specific effects of stimulants and non-stimulants in the treatment of ADHD. In total, 2672 studies were screened of which 21 studies (seven on prescription rates, 14 on effects of pharmacotherapy) met the inclusion criteria and were included for analysis.

RESULTS

In all seven studies on ADHD prescription rates, girls received significantly less prescriptions than boys, a difference however no longer seen in adults with the exception of one study. Each of the 14 studies on effectiveness / efficacy found at least one sex-difference in the effects of ADHD pharmacotherapy.

CONCLUSION

Several sex-differences are demonstrated in the prescription, usage and efficacy /effectiveness of both stimulant and non-stimulant ADHD pharmacotherapy. A single daily use of MPH may possibly not be optimal for girls with ADHD and ATX may be a promising medication for girls and women with ADHD. The robustness of this result requires further investigation.

Unseen and Stressed? Gender Differences in Parent and Teacher Ratings of ADHD Symptoms and Associations With Perceived Stress in Children With ADHD

Objective: In this study, we investigate the differences between parent and teacher ADHD ratings, and how these ratings relate to perceived stress in children with ADHD. Method: Ratings by parents and teachers with the Swanson, Nolan and Pelham ADHD symptom rating scale (SNAP-IV) were collected from children with a clinical diagnosis of ADHD (n = 137). Also, information on medication was collected. Children (≥11 years of age; n = 64) were invited to complete the Pressure-Activation-Stress scale. Results: Among girls, but not boys, teacher ratings were significantly lower than parental ratings on all symptom scales. Lower teacher ratings on hyperactivity symptoms were associated with higher levels of perceived stress. Conclusion: The findings suggest a potential gender bias in ratings among teachers. Underrated, and hence underidentified, ADHD problems in the school setting seem to increase the perception of stress in the sense of pressure for both girls and boys.

A multicenter effectiveness trial of QEEG-informed neurofeedback in ADHD: Replication and treatment prediction

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QEEG-informed neurofeedback resulted in remission rates of 55%.

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In the total sample, non-remitters had higher hyperactivity scores at baseline.

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In women, non-remitters had longer P300 latencies.

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In boys, a low individual alpha peak frequency (iAPF) was associated with remission.

Introduction

Quantitative Electroencephalogram-(QEEG-)informed neurofeedback is a method in which standard neurofeedback protocols are assigned, based on individual EEG characteristics in order to enhance effectiveness. Thus far clinical effectiveness data have only been published in a small sample of 21 ADHD patients. Therefore, this manuscript aims to replicate this effectiveness in a new sample of 114 patients treated with QEEG-informed neurofeedback, from a large multicentric dataset and to investigate potential predictors of neurofeedback response.

Methods

A sample of 114 patients were included as a replication sample. Patients were treated with standard neurofeedback protocols (Sensori-Motor-Rhythm (SMR), Theta-Beta (TBR), or Slow Cortical Potential (SCP) neurofeedback), in combination with coaching and sleep hygiene advice. The ADHD Rating Scale (ADHD-RS) and Pittsburgh Sleep Quality Index (PSQI) were assessed at baseline, every 10th session, and at outtake. Holland Sleep Disorder Questionnaire (HSDQ) was assessed at baseline and outtake. Response was defined as ≥25% reduction (R25), ≥50% reduction (R50), and remission. Predictive analyses were focused on predicting remission status.

Results

In the current sample, response rates were 85% (R25), 70% (R50), and remission was 55% and clinical effectiveness was not significantly different from the original 2012 sample. Non-remitters exhibited significantly higher baseline hyperactivity ratings. Women who remitted had significantly shorter P300 latencies and boys who remitted had significantly lower iAPF’s.

Discussion

In the current sample, clinical effectiveness was replicated, suggesting it is possible to assign patients to a protocol based on their individual baseline QEEG to enhance signal-to-noise ratio. Furthermore, remitters had lower baseline hyperactivity scores. Likewise, female remitters had shorter P300 latencies, whereas boys who remitted have a lower iAPF. Our data suggests initial specificity in treatment allocation, yet further studies are needed to replicate the predictors of neurofeedback remission.

ICP-MS Assessment of Hair Essential Trace Elements and Minerals in Russian Preschool and Primary School Children with Attention-Deficit/Hyperactivity Disorder (ADHD)

The objective of the present study was to investigate the relationship between hair essential trace element and mineral content and ADHD in preschool (4-6 years old) and primary school children (6-10 years old) in relation to age and gender. Hair essential trace element and mineral content in 90 Russian children with ADHD and 90 age- and gender-matched neurotypical controls were assessed using inductively coupled plasma mass-spectrometry after microwave digestion. The obtained data demonstrate that hair Co, Cu, Mn, Si, and Zn contents in ADHD children was significantly reduced by 18%, 10%, 27%, 16%, and 19% as compared to the control values, respectively. The most significant decrease in children with ADHD was observed for hair Mg levels, being 29% lower than those in neurotypical children. After adjustment for age and gender, the observed difference in hair element content was more characteristic for preschool children and girls, respectively. Multiple linear regression analysis demonstrated that in a crude model (hair element levels as predictors), only hair Zn content was significantly inversely associated with ADHD (β = - 0.169; p = 0.025). Adjustment for anthropometric parameters (model 2) did not increase the predictive ability of the model, although it improved the association between hair Zn and ADHD in children (β = - 0.194; p = 0.014). Hypothetically, the observed alterations may at least partially contribute to neurobehavioral disturbances in children with ADHD. Moreover, the results of the present study raise the question about the potential benefits of Zn and Mg supplementation in children with ADHD. However, further detailed studies are required to investigate micronutrient deficiencies in ADHD.

Toxoplasma gondii infection and risk of attention-deficit hyperactivity disorder: a systematic review and meta-analysis

Toxoplasma gondii (T. gondii), as an opportunistic neurotropic parasite of the Apicomplexa family, was firstly described in 1908. As attention-deficit hyperactivity disorder (ADHD) is one of the most common neuropsychiatric disorders in children and adolescents and often persists into adulthood, the purpose of this systematic review and meta-analysis was to investigate the relationship between T. gondii infection and ADHD.The data were systematically collected from seven electronic databases up to May 1^st 2019 with no language restriction. This study was registered at the International Prospective Register of Systematic Reviews (PROSPERO; code: CRD42020149353). Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using a random effects model. Seven studies involving five cross-sectional and two case-control studies were included in this meta-analysis.Results indicated that there was a statistically non-significant association between exposure to T. gondii infection and increased risk of ADHD based on the detection of immunoglobulin G (IgG) antibody (2.02 [95% CI: 0.97-4.20]; I²=58.7%). However, obtained results of Egger's tests for anti-T. gondii IgG antibody showed publication bias (P=0.014).Sensitivity analysis revealed stable results for the association between anti-T. gondii IgG antibody with ADHD.Given the small number of studies in this field and the obtained results, it cannot be conclusively stated that T. gondii is a risk factor for ADHD.It is important to have reliable information about the relationship between T. gondii and ADHD around the world; as it may lead to better insight to elucidate the possible association of toxoplasmosis and the pathogenesis of ADHD.

The Functional Impact of Sleep Disorders in Children With ADHD

Objective: Children with ADHD display higher rates of sleep problems, and both sleep disorders and ADHD have been shown to affect functioning in childhood. The current study examines the frequency and relationship between sleep problems and ADHD, and their impact on quality of life (QoL) and functional impairment. Method: Parents of 192 children with ADHD (M = 10.23 years) completed measures regarding their child's ADHD symptoms (Swanson, Nolan and Pelham [SNAP]), sleep disorders (Pediatric Sleep Questionnaire [PSQ]), QoL (Child Health Illness Profile [CHIP-PE]), and functioning (Weiss Functional Impairment Rating Scale-Parent Report [WFIRS-P]). Results: Common sleep complaints in participants were insomnia, excessive daytime sleepiness (EDS), and variability in sleep schedule. Regression analysis indicated that sleep problems and ADHD symptoms independently predicted lower levels of QoL (ΔR² = .12, p < .001) and social functioning (ΔR² = .12, p < .001). Conclusion: The results suggest that ADHD may coexist with somnolence and that both conditions have a significant impact on a child's functioning and QoL.

Developmental trajectories of childhood symptoms of hyperactivity/inattention and suicidal behavior during adolescence

Hyperactive/inattentive symptoms (ADHD symptoms) are associated with suicidal behavior in clinical studies, but there is still a lack of population-based longitudinal investigations on the developmental aspects of this association. Additionally, it is unclear whether the association is similar for boys and girls. The objectives of the study were to test the association between the ADHD symptoms during childhood and suicidal ideation and attempt during adolescence, and to investigate sex differences. 1407 children from the Québec Longitudinal Study of Child Development were followed up from 5 months to 17 years of age. We used teacher-reports of ADHD symptoms from 6 to 12 years, and self-report of suicidal ideation and attempt at 13, 15, and 17 years. We identified three ADHD symptoms trajectories: low (boys: 32.2%, girls: 48.7%), moderate (boys: 44.6%; girls: 42.2%) and high (boys: 23.2%; girls: 9.1%). Compared to boys on a low trajectory, boys on a moderate trajectory were at higher risk for suicidal ideation (OR 4.2, 95% CI 1.2-14.8), and boys on a high trajectory were at higher risk for suicide attempts (OR 4.5, 95% CI 1.1-17.9). Girls on moderate or high ADHD symptoms trajectories were not at higher risk for suicidal ideation or attempts than girls on low trajectories. For boys, but not for girls, moderate-to-high ADHD symptoms increased the suicidal risk in adolescence. Interventions with boys showing ADHD symptoms should include a suicide prevention component.

Health Care Trajectories for Children With ADHD in France: Results From the QUEST Survey

Objective: The objective of this study is to retrospectively describe the pathway toward ADHD diagnosis and treatment, and identify potential areas for improvement. Method: Parent-reported questionnaires were collected by a national sample of ADHD specialists. Results: In total, 473 complete questionnaires were analyzed. Initial onset of ADHD symptoms was reported at a mean age of 4.45 years. Mean age at diagnosis was 8.07 years, and half of the families had seen at least three health care professionals previously. Psychiatrists were most commonly consulted. A "combined" (89% boys) and inattentive (49% boys) profile was identified. Diagnosis was made 1 year later for the latter group. Two thirds of patients received pharmacological treatment. The delay in diagnosis was identified as the main source of concern for caregivers. Conclusion: The 4-year delay in diagnosis may represent a loss of opportunity. Training health care professionals in the core symptoms of ADHD may help reduce disparities and improve patient trajectory.

Prenatal exposure to perfluoroalkyl substances and associations with symptoms of attention-deficit/hyperactivity disorder and cognitive functions in preschool children

BACKGROUND

Perfluoroalkyl substances (PFASs) are persistent organic pollutants that are suspected to be neurodevelopmental toxicants, but epidemiological evidence on neurodevelopmental effects of PFAS exposure is inconsistent. We investigated the associations between prenatal exposure to PFASs and symptoms of attention-deficit/hyperactivity disorder (ADHD) and cognitive functioning (language skills, estimated IQ and working memory) in preschool children, as well as effect modification by child sex.

MATERIAL AND METHODS

This study included 944 mother-child pairs enrolled in a longitudinal prospective study of ADHD symptoms (the ADHD Study), with participants recruited from The Norwegian Mother, Father and Child Cohort Study (MoBa). Boys and girls aged three and a half years, participated in extensive clinical assessments using well-validated tools; The Preschool Age Psychiatric Assessment interview, Child Development Inventory and Stanford-Binet (5th revision). Prenatal levels of 19 PFASs were measured in maternal blood at week 17 of gestation. Multivariable adjusted regression models were used to examine exposure-outcome associations with two principal components extracted from the seven detected PFASs. Based on these results, we performed regression analyses of individual PFASs categorized into quintiles.

RESULTS

PFAS component 1 was mainly explained by perfluoroheptane sulfonate (PFHpS), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS) and perfluorooctanoic acid (PFOA). PFAS component 2 was mainly explained by perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA) and perfluorononanoic acid (PFNA). Regression models showed a negative association between PFAS component 1 and nonverbal working memory [β = -0.08 (CI: -0.12, -0.03)] and a positive association between PFAS component 2 and verbal working memory [β = 0.07 (CI: 0.01, 0.12)]. There were no associations with ADHD symptoms, language skills or IQ. For verbal working memory and PFAS component 2, we found evidence for effect modification by child sex, with associations only for boys. The results of quintile models with individual PFASs, showed the same pattern for working memory as the results in the component regression analyses. There were negative associations between nonverbal working memory and quintiles of PFOA, PFNA, PFHxS, PFHpS and PFOS and positive associations between verbal working memory and quintiles of PFOA, PFNA, PFDA and PFUnDA, with significant relationships mainly in the highest concentration groups.

CONCLUSIONS

Based on our results, we did not find consistent evidence to conclude that prenatal exposure to PFASs are associated with ADHD symptoms or cognitive dysfunctions in preschool children aged three and a half years, which is in line with the majority of studies in this area. Our results showed some associations between PFASs and working memory, particularly negative relationships with nonverbal working memory, but also positive relationships with verbal working memory. The relationships were weak, as well as both positive and negative, which suggest no clear association - and need for replication.

Drug Prescriptions for Children With ADHD in Japan: A Study Based on Health Insurance Claims Data Between 2005 and 2015

Objective: The aim of this study is to investigate the trend of prescription drugs for children with ADHD in Japan. Method: Using health insurance claims data of 3,672,951 people between January 2005 and December 2015, we investigated the trend of prescription drugs for 7,856 children with ADHD. Results: After approval in 2007, the proportion of prescriptions for methylphenidate-osmotic-controlled release oral delivery system tablets was 31.4% in 2009 (adjusted odds ratio [AOR] = 2.72; 95% confidence interval [CI] = [2.12, 3.51]) and reached a plateau approximately after 2009 (AOR = 0.96; 95% CI = [0.94, 0.98]). The proportion of prescriptions for atomoxetine increased from 6.1% in 2008 to 21.8% in 2014 (AOR = 1.12; 95% CI = [1.13, 1.18]). The proportion of prescriptions for aripiprazole and ramelteon increased (all trend p < .001). Conclusion: Prescriptions of drugs for children with ADHD have changed. We need to monitor the safety of ADHD medications among children with ADHD.

Signatures of sex: Sex differences in gene expression in the vertebrate brain

Women and men differ in disease prevalence, symptoms, and progression rates for many psychiatric and neurological disorders. As more preclinical studies include both sexes in experimental design, an increasing number of sex differences in physiology and behavior have been reported. In the brain, sex-typical behaviors are thought to result from sex-specific patterns of neural activity in response to the same sensory stimulus or context. These differential firing patterns likely arise as a consequence of underlying anatomic or molecular sex differences. Accordingly, gene expression in the brains of females and males has been extensively investigated, with the goal of identifying biological pathways that specify or modulate sex differences in brain function. However, there is surprisingly little consensus on sex-biased genes across studies and only a handful of robust candidates have been pursued in the follow-up experiments. Furthermore, it is not known how or when sex-biased gene expression originates, as few studies have been performed in the developing brain. Here we integrate molecular genetic and neural circuit perspectives to provide a conceptual framework of how sex differences in gene expression can arise in the brain. We detail mechanisms of gene regulation by steroid hormones, highlight landmark studies in rodents and humans, identify emerging themes, and offer recommendations for future research. This article is categorized under: Nervous System Development > Vertebrates: General Principles Gene Expression and Transcriptional Hierarchies > Regulatory Mechanisms Gene Expression and Transcriptional Hierarchies > Sex Determination.

Secondhand smoke as a risk factor for attention deficit hyperactivity disorder in children

Background: Attention deficit hyperactivity disorder (ADHD) is recognized as a common childhood psychiatric disorder‏ with a worldwide prevalence estimated at 5%. In Egypt, early exposure of children to smoke occurred due to many causes mainly tobacco use. This exposure is linked to a variety of developmental and behavioral consequences for children. This study aimed to investigate the potential association between secondhand smoke (SHS) exposure and ADHD in children and find the association between the level of exposure to SHS and the degree of ADHD symptoms.Method: Case-control study was done by a random selection of children from the outpatient Clinic of Assiut University Hospital of Children. Data were collected by a questionnaire to evaluate home exposure to SHS and blood sampling for serum cotinine measurement as an indicator of exposure to SHS.Results: Of 70 ADHD children, 62 (88.6%) of them reported home exposure to smoke while only 14 of 30 control children (46.7%) reported home exposure to smoke. The serum cotinine level was insignificantly higher in the ADHD group than the control group.Conclusion: In conclusion, there is a significant association between ADHD in the examined sample of children and exposure to SHS. Serum cotinine is a biomarker reflecting current exposure to SHS but it is not a reliable indicator of past and long-term exposure to SHS.

Chronic Pain And Health-Related Quality Of Life In Women With Autism And/Or ADHD: A Prospective Longitudinal Study

Purpose

To investigate the prevalence of chronic pain and its association with health-related quality of life (HRQoL) in a group of women, diagnosed with autism spectrum disorder (ASD) and/or attention deficit hyperactive disorder (ADHD) in childhood.

Patients and methods

Prospective longitudinal 16–19 years follow-up study of 100 Swedish females diagnosed with ASD and/or ADHD in childhood/adolescence. Seventy-seven of the women were included in the current sub-study, using validated measures of pain perception and quality of life.

Results

A large majority of the women (76.6%) reported chronic pain. HRQoL was low overall and lower still for those reporting chronic pain. Women with ADHD who had ongoing treatment with stimulants reported a significant lower prevalence of chronic widespread pain (CWP) than those not treated.

Conclusion

Comorbidity with chronic pain is common in women with ASD and/or ADHD and important to address in the clinic since it is associated with an already low HRQoL. Treatment for ADHD might reduce the pain in some cases.

Peripheral Brain-Derived Neurotrophic Factor and Contactin-1 Levels in Patients with Attention-Deficit/Hyperactivity Disorder

Brain-derived neurotrophic factor (BDNF) facilitates neuronal growth and plasticity, and is crucial for learning and memory. Contactin-1 (CNTN1) is a member of the subfamily of neural immunoglobulin and is involved in the formation of axon connections in the developing nervous system. This cross-sectional study investigates whether BDNF and CNTN1 affect susceptibility to attention deficit/hyperactivity disorder (ADHD). A total of 136 drug-naïve patients with ADHD (108 boys and 28 girls) and 71 healthy controls (45 boys and 26 girls) were recruited. Blood samples were obtained to measure the plasma levels of BDNF and CNTN1 in each child. We found that BDNF levels in the ADHD boys exceeded those in the control boys, but BDNF levels in the ADHD girls were lower than those in the control girls. Boys who had higher BDNF levels performed worse on the Wechsler Intelligence Scale for Children—Fourth Edition, but girls who had higher BDNF levels made fewer omission errors in the Conners’ Continuous Performance Test. However, CNTN1 level did not differ significantly between patients and controls, and were not correlated to ADHD characteristics, regardless of gender. The findings suggest BDNF may influence sex-specific susceptibility to ADHD, but CNTN1 was not associated with ADHD pathophysiology.

Psychiatric Comorbidity and Demographic Characteristics of 1,000 Children and Adolescents With ADHD in Turkey

Objective: The objective was to examine the frequency of comorbid disorders in children and adolescents with ADHD in Turkey and to evaluate the distribution of comorbidities according to the subtypes of ADHD and sociodemographic features. Method: The sample consisted of 1,000 children, 6 to 18 years of age, including 242 females and 758 males, from Ege University who were diagnosed with ADHD. Results: The overall prevalence rate of psychiatric comorbidity in the study was 56.3%. The most frequently observed comorbidity was oppositional defiant disorder with a rate of 37.4%. Conduct disorder, depressive disorder, obsessive-compulsive disorder, and anxiety disorder accompanied ADHD, respectively. The results revealed that 70.2% of the children with ADHD-Combine type had at least one psychiatric comorbidity. Oppositional defiant disorder, conduct disorder, depressive disorder, and obsessive-compulsive disorder accompanied ADHD-Combine type in 54.6%, 12.6%, 8.1%, and 8.8% of the participants, respectively. Conclusion: These findings provide valuable information about the comorbid disorders in children and adolescents with a very large clinical sample of ADHD children.

Evidence of concurrent and prospective associations between early maltreatment and ADHD through childhood and adolescence

PURPOSE

An emerging body of work suggests a link between childhood maltreatment and attention-deficit hyperactivity disorder (ADHD). However, research examining the role of maltreatment in the early course of the disorder lacks robust evidence from longitudinal studies. Our aim was to examine concurrent and prospective associations between maltreatment experiences and ADHD diagnosis and sex differences, and to estimate the association between repetitive maltreatment exposure and ADHD through childhood and adolescence.

METHODS

Data were obtained from the Boricua Youth Study, a longitudinal study of 2480 children and adolescents of Puerto Rican background. Neglect, physical, emotional and sexual abuse, and foster placement were regressed on ADHD diagnosis measured at each of three waves using the Diagnostic Interview Schedule for Children-IV. Multilevel regressions estimated the effects of exposure on ADHD, adjusted by age, sex, income, household education, parental psychopathology, comorbidity and ADHD medication status.

RESULTS

Emotional abuse and foster placement had robust associations with ADHD diagnosis. For girls, physical abuse had a threefold increase in the odds of having ADHD diagnosis; for boys, associations were observed only for emotional abuse. Prospective models examining the risk of ADHD following maltreatment provided initial evidence for the effects of physical abuse on ADHD, and a linear trend for repetitive exposure suggested increased probability for disorder persistence.

CONCLUSIONS

Associations between early maltreatment and ADHD were robust. Different categories of maltreatment increase the likelihood of ADHD for girls and boys. Increased exposure to maltreatment may predict symptom persistence. Interventions addressing ADHD must consider the effects of both sex and family environment.

Towards interpretable machine learning models for diagnosis aid: A case study on attention deficit/hyperactivity disorder

Attention Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder that has heavy consequences on a child's wellbeing, especially in the academic, psychological and relational planes. The current evaluation of the disorder is supported by clinical assessment and written tests. A definitive diagnosis is usually made based on the DSM-V criteria. There is a lot of ongoing research on ADHD, in order to determine the neurophysiological basis of the disorder and to reach a more objective diagnosis. The advent of Machine Learning (ML) opens up promising prospects for the development of systems able to predict a diagnosis from phenotypic and neuroimaging data. This was the reason why the ADHD-200 contest was launched a few years ago. Based on the publicly available ADHD-200 collection, participants were challenged to predict ADHD with the best possible predictive accuracy. In the present work, we propose instead a ML methodology which primarily places importance on the explanatory power of a model. Such an approach is intended to achieve a fair trade-off between the needs of performance and interpretability expected from medical diagnosis aid systems. We applied our methodology on a data sample extracted from the ADHD-200 collection, through the development of decision trees which are valued for their readability. Our analysis indicates the relevance of the limbic system for the diagnosis of the disorder. Moreover, while providing explanations that make sense, the resulting decision tree performs favorably given the recent results reported in the literature.

Pubertal influences on neural activation during risky decision-making in youth with ADHD and disruptive behavior disorders

OBJECTIVE

Risk-taking during adolescence is a leading cause of mortality; Neuroscience research examining pubertal effects on decision-making is needed to better inform interventions, particularly among youth with attention-deficit/hyperactivity (ADHD) and disruptive behavior disorders (DBD), who are particularly prone to risky decision-making. We examined effects of pubertal development on risky decision-making and neural activation during decision-making among youth with ADHD/DBDs.

METHOD

Forty-six 11-12-year-olds (29.4% girls; 54.9% white; Tanner M(SD) = 2.08(1.32)) who met DSM-5 criteria for ADHD/DBD completed the Balloon Analog Risk Task (BART) during fMRI scanning. We examined effects of Tanner stage, sex, and age on risky decision-making (mean wager at which individuals stopped balloon inflation) and neural activation in the middle frontal gyrus and the ventral striatum during the choice and outcome phases of decision-making.

RESULTS

Those in earlier pubertal stages made riskier decisions during the BART compared to those in later Tanner stages (β=-0.62, p =  .02). Later pubertal stage was associated with greater activation in the left middle frontal gyrus (β=0.61, p = .03) during the choice phase and in the right ventral striatum in response to rewards (β=0.59, p = .03).

CONCLUSION

Youth with ADHD/DBD in later stages of puberty, regardless of age, show greater ventral striatal activation in response to rewards.

Comorbidity and sociodemographic characteristics of adult autism spectrum disorder and attention deficit hyperactivity disorder: epidemiological investigation in the World Mental Health Japan 2nd Survey

Objectives: The present study aims to examine sociodemographic correlates and comorbid mental disorders among adult with autism spectrum disorders (ASD) and attention deficit hyperactivity disorders (ADHD) using the national representative data of Japan. Methods: Analysis was conducted on the cross-sectional data derived from the World Mental Health Japan Survey 2, whose participants were community residents aged 20-75 years old. Multiple logistic regression was conducted on the data of those who were assessed for adult ASD (N = 2227) and ADHD (N = 2297). The association of adult ASD/ADHD with sociodemographics, mood disorders, anxiety disorders, substance use disorders, suicide ideation, hikikomori (social withdrawal), and internet addiction was examined, adjusting for sex and age. Gender difference in the association was also assessed based on the interaction terms of sex. Results: None of the sociodemographics characteristics were significantly associated with adult ASD/ADHD. ADHD had increased risks for a variety of mental disorders, having the highest odds ratios for social phobia. However, a significant positive association was limited to social phobia and to drug abuse and dependence among those with adult ASD. Hikikomori and internet addiction were positively associated with ASD/ADHD, while suicide ideation was only associated with ADHD. Women with ADHD were more likely to have any one of mental disorders, as well as alcohol abuse and dependence, compared to men with ADHD. Conclusions: Adults with ASD/ADHD in Japan had increased mental health needs. The specific needs of women with ADHD should be also considered in future clinical work and research.

Early sleep deprivation and attention-deficit/hyperactivity disorder

BACKGROUND

This study aims to study prospectively specific sleep patterns and risk of ADHD after adjusting for potential confounders such as obstructive sleep apnoea (OSA) and methylphenidate use.

METHODS

A population-representative sample of 514 Chinese preschool children was recruited when in kindergarten (K3). Parents reported on their socioeconomic status and children's sleep duration. The cohort was reassessed 3 years later when the children were in Grade 3 (P3). Parents reported on children's sleep patterns and ADHD symptoms. Information on OSA diagnosis and methylphenidate use was retrieved from health records.

RESULTS

Among the 514 parent-child dyads (mean [SD] age, 5.52 [0.33] years), 411 were reassessed (80.0% retention; 9.35 [0.33] years) at follow-up. There were no significant baseline differences between follow-up and drop-out groups. A gradient relationship was observed between probable ADHD in P3 and sleep duration in K3. The risk of probable ADHD was 15.5 per 100 for children with <8 h of sleep in K3, whereas it was 1.1 per 100 for children with 11-12 h of sleep in K3. The adjusted risk ratio was 14.19 (p = 0.02).

CONCLUSIONS

Sleep deprivation in early childhood is associated with higher risk of ADHD in middle childhood.

Evaluating a scale of excessive mind wandering among males and females with and without attention-deficit/hyperactivity disorder from a population sample

Recent studies highlight the role of excessive mind wandering in attention-deficit/hyperactivity disorder (ADHD) and its association with impairment. We believe assessing mind wandering could be especially relevant to individuals, including many females, who present with less externalising manifestations of ADHD. Using a new measure based on ADHD patient reports, the Mind Excessively Wandering Scale (MEWS), we previously found adults with ADHD had elevated levels of mind wandering that contributed to impairment independently of core ADHD symptoms. Using data from an online general population survey, the current study assessed the factor-structure, reliability, validity and measurement invariance of the MEWS. We also investigated sex differences in mind wandering, as well as ADHD symptoms, impairment and wellbeing in those with and without ADHD. The MEWS had a unidimensional structure, was invariant across sex, age and ADHD status, and accounted for unique variance in impairment and wellbeing beyond core ADHD symptoms. Among those with ADHD, we found no evidence for sex differences in mind wandering and among those without ADHD males had higher scores. We also found similar levels of hyperactivity/impulsivity, emotional lability, and impairment in males and females with ADHD, but males reported greater inattention and lower wellbeing. Results suggest the MEWS is a reliable and valid instrument measuring the same construct across sex, age and ADHD status, which could aid diagnosis and monitoring of outcomes.

Little evidence for late-onset ADHD in a longitudinal sample of women

OBJECTIVE

Individuals with late-onset symptoms of attention-deficit/hyperactivity disorder (ADHD) are presenting to providers at increasing rates. Recent birth-cohort studies reveal evidence for late-onset ADHD, but conclusions are challenged by measurement methods as well as presence of participant impairment and psychiatric comorbidities. We examined the occurrence of late-onset ADHD in a small but thoroughly investigated group of diverse (47% white) women followed from childhood to adulthood.

METHOD

From a larger, 16-year longitudinal study, a subsample of young women without childhood ADHD (N = 87) was assessed at four time points between childhood and adulthood via a multimethod, multiinformant approach. We used a stepped diagnostic procedure to identify those who initially met symptom criteria for ADHD after childhood and then evaluated them for remaining DSM ADHD diagnostic criteria, including impairment, cross-situational symptoms, and comorbid diagnoses.

RESULTS

Of 87 participants, 17 met ADHD symptom criteria after childhood. Fifteen showed no evidence of childhood onset, 10 showed clear evidence of impairment, and nine had cross-situational symptoms. Of these nine, all but one showed clinically significant co-occurring or preexisting psychiatric diagnoses and/or substance use that might account for ADHD symptoms.

CONCLUSIONS

Although 19.5% of women from our subsample without childhood ADHD met symptom criteria for ADHD during adolescence/adulthood, only one showed the needed combination of impairment and cross-situational symptoms without significant co-occurring mental health problems. It is possible that uncomplicated cases of adult ADHD do arise, yet we find little supporting evidence herein. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Cross-species models of attention-deficit/hyperactivity disorder and autism spectrum disorder: lessons from CNTNAP2, ADGRL3, and PARK2

Animal and cellular models are essential tools for all areas of biological research including neuroscience. Model systems can also be used to investigate the pathophysiology of psychiatric disorders such as attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). In this review, we provide a summary of animal and cellular models for three genes linked to ADHD and ASD in human patients - CNTNAP2, ADGRL3, and PARK2. We also highlight the strengths and weaknesses of each model system. By bringing together behavioral and neurobiological data, we demonstrate how a cross-species approach can provide integrated insights into gene function and the pathogenesis of ADHD and ASD. The knowledge gained from transgenic models will be essential to discover and validate new treatment targets for these disorders.

Attention-deficit/hyperactivity disorder and risk for psychiatric and neurodevelopmental disorders in siblings

BACKGROUND

Probands with attention-deficit/hyperactivity disorder (ADHD) are at increased risk for several psychiatric and neurodevelopmental disorders. The risk of these disorders among the siblings of probands has not been thoroughly assessed in a population-based cohort.

METHODS

Every child born in Finland in 1991-2005 and diagnosed with ADHD in 1995-2011 were identified from national registers. Each case was matched with four controls on sex, place, and date of birth. The full siblings of the cases and controls were born in 1981-2007 and diagnosed in 1981-2013. In total, 7369 cases with 12 565 siblings and 23 181 controls with 42 753 siblings were included in the analyses conducted using generalized estimating equations.

RESULTS

44.2% of the cases and 22.2% of the controls had at least one sibling diagnosed with any psychiatric or neurodevelopmental disorder (risk ratio, RR = 2.1; 95% CI 2.0-2.2). The strongest associations were demonstrated for childhood-onset disorders including ADHD (RR = 5.7; 95% CI 5.1-6.3), conduct and oppositional disorders (RR = 4.0; 95% CI 3.5-4.5), autism spectrum disorders (RR = 3.9; 95% CI 3.3-4.6), other emotional and social interaction disorders (RR = 2.7; 95% CI 2.4-3.1), learning and coordination disorders (RR = 2.6; 95% CI 2.4-2.8), and intellectual disability (RR = 2.4; 95% CI 2.0-2.8). Also, bipolar disorder, unipolar mood disorders, schizophrenia spectrum disorders, other neurotic and personality disorders, substance abuse disorders, and anxiety disorders occurred at increased frequency among the siblings of cases.

CONCLUSIONS

The results offer potential utility for early identification of neurodevelopmental and psychiatric disorders in at-risk siblings of ADHD probands and also argue for more studies on common etiologies.

Cross-Cultural and Gender Differences in ADHD Among Young Adults

OBJECTIVE

This study explored the effect of cultural and gender differences in ADHD among Spanish, African American, Hispanic American, and European American young adults.

METHOD

Structural equivalence between the four groups was examined by Tucker's phi coefficient. A MANCOVA was carried out with cultural groups and gender as factors and age as covariate.

RESULTS

Structural equivalence was observed across all groups, and no differential item functioning was found. No significant effect was found for gender, although, with the exception of the Hispanic group, males scored higher than females. Furthermore, small, though significant, cultural differences were found. The lowest levels of ADHD were observed in the European American group and the highest in the Hispanic American group. ADHD symptoms, notably inattention, showed some decline with age.

CONCLUSION

Findings extend existing data and suggest a relationship between culture and the development of ADHD, which might be mediated by parenting style.

Screening for the ADHD Phenotype Using the Strengths and Difficulties Questionnaire in a Clinical Sample of Newly Referred Children and Adolescents

OBJECTIVE

To examine the screening ability of the Strengths and Difficulties Questionnaire (SDQ) for ADHD subtypes in a clinical sample.

METHOD

Parents of 523 children (3 to 17 years old) referred to Child and Adolescent Mental Health Services completed the Spanish version of the SDQ and the ADHD Rating Scale-IV. Receiver operating curve (ROC) curve analyses and likelihood ratios (LRs) were conducted.

RESULTS

The LR results indicated that the 8/10 cutoff showed the highest diagnostic accuracy. The sensitivity of the SDQ 8/10 cutoff for the three subtypes was significantly different: 84.0% (95% confidence interval [CI] = [75.58, 89.90]) of ADHD combined subtype (ADHD-Co), 25.0% (95% CI = [17.55, 34.30]) of ADHD predominantly inattentive subtype (ADHD-I), and 77.8% (95% CI = [68.71, 84.83]) of ADHD predominantly hyperactive/impulsive subtype (ADHD-H). Sex and age differences were found. These screening differences were also found when using the 7/10 cutoff or the SDQ predictive algorithm.

CONCLUSION

Our study supports the use of the SDQ in the screening for ADHD. However, not all ADHD subtypes are equally screened.

Sex-specific manifestation of genetic risk for attention deficit hyperactivity disorder in the general population

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is more commonly diagnosed in males than in females. A growing body of research suggests that females with ADHD might be underdiagnosed or receive alternative diagnoses, such as anxiety or depression. Other lines of reasoning suggest that females might be protected from developing ADHD, requiring a higher burden of genetic risk to manifest the disorder.

METHODS

We tested these two hypotheses, using common variant genetic data from two population-based cohorts. First, we tested whether females and males diagnosed with anxiety or depression differ in terms of their genetic risk for ADHD, assessed as polygenic risk scores (PRS). Second, we tested whether females and males with ADHD differed in ADHD genetic risk burden. We used three different diagnostic definitions: registry-based clinical diagnoses, screening-based research diagnoses and algorithm-based research diagnoses, to investigate possible referral biases.

RESULTS

In individuals with a registry-based clinical diagnosis of anxiety or depression, females had higher ADHD PRS than males [OR(CI) = 1.39 (1.12-1.73)] but there was no sex difference for screening-based [OR(CI) = 1.15 (0.94-1.42)] or algorithm-based [OR(CI) = 1.04 (0.89-1.21)] diagnoses. There was also no sex difference in ADHD PRS in individuals with ADHD diagnoses that were registry-based [OR(CI) = 1.04 (0.84-1.30)], screening-based [OR(CI) = 0.96 (0.85-1.08)] or algorithm-based [OR(CI) = 1.15 (0.78-1.68)].

CONCLUSIONS

This study provides genetic evidence that ADHD risk may be more likely to manifest or be diagnosed as anxiety or depression in females than in males. Contrary to some earlier studies, the results do not support increased ADHD genetic risk in females with ADHD as compared to affected males.

Gene regulatory mechanisms underlying sex differences in brain development and psychiatric disease

The sexual differentiation of the mammalian nervous system requires the precise coordination of the temporal and spatial regulation of gene expression in diverse cell types. Sex hormones act at multiple developmental time points to specify sex-typical differentiation during embryonic and early development and to coordinate subsequent responses to gonadal hormones later in life by establishing sex-typical patterns of epigenetic modifications across the genome. Thus, mutations associated with neuropsychiatric conditions may result in sexually dimorphic symptoms by acting on different neural substrates or chromatin landscapes in males and females. Finally, as stress hormone signaling may directly alter the molecular machinery that interacts with sex hormone receptors to regulate gene expression, the contribution of chronic stress to the pathogenesis or presentation of mental illness may be additionally different between the sexes. Here, we review the mechanisms that contribute to sexual differentiation in the mammalian nervous system and consider some of the implications of these processes for sex differences in neuropsychiatric conditions.

Differential Behavioral and Biochemical Responses to Caffeine in Male and Female Rats from a Validated Model of Attention Deficit and Hyperactivity Disorder

Epidemiological studies suggest sex differences in attention deficit and hyperactivity disorder (ADHD) symptomatology. The potential benefits of caffeine have been reported in the management of ADHD, but its effects were not properly addressed with respect to sex differences. The present study examined the effects of caffeine (0.3 g/L) administered since childhood in the behavior and brain-derived neurotrophic factor (BDNF) and its related proteins in both sexes of a rat model of ADHD (spontaneously hypertensive rats-SHR). Hyperlocomotion, recognition, and spatial memory disturbances were observed in adolescent SHR rats from both sexes. However, females showed lack of habituation and worsened spatial memory. Although caffeine was effective against recognition memory impairment in both sexes, spatial memory was recovered only in female SHR rats. Besides, female SHR rats showed exacerbated hyperlocomotion after caffeine treatment. SHR rats from both sexes presented increases in the BDNF, truncated and phospho-TrkB receptors and also phospho-CREB levels in the hippocampus. Caffeine normalized BDNF in males and truncated TrkB receptor at both sexes. These findings provide insight into the potential of caffeine against fully cognitive impairment displayed by females in the ADHD model. Besides, our data revealed that caffeine intake since childhood attenuated behavioral alterations in the ADHD model associated with changes in BDNF and TrkB receptors in the hippocampus.

Gender Differences in the Relationship Between Changes in ADHD Symptoms, Executive Functions, and Self- and Parent-Report Depression Symptoms in Boys and Girls With ADHD: A 2-Year Follow-Up Study

OBJECTIVE

This study was conducted to investigate the association between changes in ADHD symptoms, executive functions (EFs), and depression symptoms in girls and boys with ADHD over a 2-year period.

METHOD

Thirty-six girls and 39 boys with ADHD, 18 typically developing (TD) girls and 29 TD boys (ages 9-16) were included. Assessments of EFs, ADHD symptoms, and self- and parent-report of depression symptoms were carried out.

RESULTS

For girls, a reduction of inattention symptoms was associated with a decline in parent-rated depression symptoms. A reduction in hyperactivity/impulsivity was associated with a reduction in self-rated depression symptoms in boys, and an increase in girls. A reduction in inattention symptoms was associated with a modest increase in self-rated depression symptoms in both boys and girls.

CONCLUSION

Gathering information from both the parents and the child with ADHD is important in determining how gender may be influencing symptom profiles.

Conhecimentos e Lacunas dos Professores do 1. º Ciclo acerca da PHDA

Pretendeu-se analisar o conhecimento dos profesores (n = 419) acerca da Perturbação de Hiperatividade/Défice de Atenção (PHDA), através do “Questionário de Avaliação do Conhecimento da PHDA”, no qual se pronunciaram acerca de diferentes questões (e.g., etiología, intervenção). Os docentes mostraram-se moderadamente informados (e.g., 78.8% sabe que a utilização exclusiva da punição na gestão comportamental não é uma intervenção eficaz), embora haja espaço para melhoria, (e.g., apenas 26.7% considerou determinante o papel da hereditariedade). Estes dados devem ser considerados no planeamento da formação da classe docente. 

Prevalence rates of youths diagnosed with and medicated for ADHD in a nationwide survey in Taiwan from 2000 to 2011

AIMS

Public controversy regarding the potential overdiagnosis and overmedication of children with attention-deficit/hyperactivity disorder (ADHD) has continued for decades. This study used the National Health Insurance Research Database of Taiwan (NHIRD-TW) to explore trends in ADHD diagnosis in youths and the proportion of those receiving medication, with the aim of determining whether ADHD is overdiagnosed and overmedicated in Taiwan.

METHOD

Youths (age ≤18 years) who had at least two NHIRD-TW claims records with ADHD diagnosis between January 2000 and December 2011 were selected as the subject cohort. In total, the study sample comprised 145 018 patients with ADHD (mean age at a diagnosis of ADHD: 7.7 ± 3.1 years; 21.4% females). The number of cases of ADHD were calculated annually for each year (from 2000 to 2011), and the number of cases per year who received medication was determined as those with at least one record of pharmacotherapy (immediate-release methylphenidate, osmotic controlled-release formulation of methylphenidate, and atomoxetine) in each year.

RESULTS

The prevalence rates of a diagnosis of ADHD in the youths ranged from 0.11% in 2000 to 1.24% in 2011. Compared with children under 6 years of age, the ADHD diagnosis rates in children aged between 7 and 12 years (ratio of prevalence rates = 4.36) and in those aged between 13 and 18 years (ratio of prevalence rates = 1.42) were significantly higher during the study period. The prevalence in males was higher than that in females (ratio of prevalence rates = 4.09). Among the youths with ADHD, 50.2% received medications in 2000 compared with 61.0% in 2011. The probability of receiving ADHD medication increased with age. More male ADHD patients received medications that females patients (ratio of prevalence rates = 1.16).

CONCLUSIONS

The rate of ADHD diagnosis was far lower than the prevalence rate (7.5%) identified in a previous community study using face-to-face interviews. Approximately 40-50% of the youths with ADHD did not receive any medications. These findings are not consistent with a systematic public opinion about overdiagnosis or overmedication of ADHD in Taiwan.

Sex differences in stress regulation of arousal and cognition

There are sex differences in the prevalence and presentation of many psychiatric disorders. For example, posttraumatic stress disorder (PTSD) and major depression are more common in women than men, and women with these disorders present with more hyperarousal symptoms than men. In contrast, attention deficit hyperactivity disorder (ADHD) and schizophrenia are more common in men than women, and men with these disorders have increased cognitive deficits compared to women. A shared feature of the aforementioned psychiatric disorders is the contribution of stressful events to their onset and/or severity. Here we propose that sex differences in stress responses bias females towards hyperarousal and males towards cognitive deficits. Evidence from clinical and preclinical studies is detailed. We also describe underlying neurobiological mechanisms. For example, sex differences in stress receptor signaling and trafficking in the locus coeruleus-arousal center are detailed. In learning circuits, evidence for sex differences in dendritic morphology is provided. Finally, we describe how evaluating sex-specific mechanisms for responding to stress in female and male rodents can lead to better treatments for stress-related psychiatric disorders.

How Persistent is ADHD into Adulthood? Informant Report and Diagnostic Thresholds in a Female Sample

The persistence of attention-deficit/hyperactivity disorder (ADHD) into adulthood, particularly in women, is an unresolved question. Using a diverse, prospectively followed female sample (ADHD: n = 140; comparison: n = 88), we examined (a) informant (parent- vs. self-report) and (b) symptom threshold (DSM-IV cutoffs vs. a developmentally referenced criterion [DRC]) with respect to estimates of ADHD persistence into young adulthood (M = 19.6 years). We also ascertained the linkages of ADHD status (as measured by each informant and via the different symptom cutoffs) with impairment in key outcome domains. Informant diagnostic concordance was significant but small (κ = 0.22). Via parent report, more childhood-ascertained probands (44 %) than comparison participants (1 %) met full ADHD criteria in adulthood (p < 0.001, ϕ = 0.47); parallel results were found via self-report (22 % vs. 2 %; p < 0.001, ϕ = 0.28). As expected, DRC designations yielded higher persistence estimates than DSM cutoffs. With control of key covariates, parent-reported ADHD was independently associated with poor outcomes on eight of nine measures but self-reported ADHD was associated only with low math scores. Also, participants who met the DRC cutoff but not the higher DSM threshold showed similar impairment to DSM-diagnosed participants, far greater than that of participants who met neither cutoff. A lowered symptom threshold in adulthood compared to childhood appears justified.

Annual Research Review: Quality of life and childhood mental and behavioural disorders - a critical review of the research

BACKGROUND

An individual's subjective perception of well-being is increasingly recognized as an essential complement to clinical symptomatology and functional impairment in children's mental health. Measurement of quality of life (QoL) has the potential to give due weight to the child's perspective.

SCOPE AND METHODOLOGY

Our aim was to critically review the current evidence on how childhood mental disorders affect QoL. First, the major challenges in this research field are outlined. Then we present a systematic review of QoL in children and adolescents aged 0-18 years formally diagnosed with a mental and behavioural disorder, as compared to healthy or typically developing children or children with other health conditions. Finally, we discuss limitations of the current evidence base and future directions based on the results of the systematic review and other relevant literature.

FINDINGS AND CONCLUSIONS

The systematic review identified 41 eligible studies. All were published after the year 2000 and 21 originated in Europe. The majority examined QoL in neurodevelopmental disorders, including attention-deficit hyperactivity disorder (k = 17), autism spectrum disorder (k = 6), motor disorders (k = 5) and intellectual disability (k = 4). Despite substantial heterogeneity, studies demonstrate that self-reported global QoL is significantly reduced compared to typical/healthy controls across several disorders and QoL dimensions. Parents' ratings were on average substantially lower, casting doubt on the validity of proxy-report. Studies for large diagnostic groups such as depressive disorders, anxiety disorders, (early onset) schizophrenia and eating disorders are largely lacking. We conclude that representative, well-characterized normative and clinical samples as well as longitudinal and qualitative designs are needed to further clarify the construct of QoL, to derive measures of high ecological validity, and to examine how QoL fluctuates over time and is attributable to specific conditions or contextual factors.

Experiences of employed women with attention deficit hyperactive disorder: A phenomenological study

BACKGROUND

Employees with attention-deficit/hyperactivity disorder (ADHD) face various risks in the workplace. Little is known of the specific challenges women with ADHD experience.

OBJECTIVE

To explore the experiences of working women with ADHD and learn the strategies and accommodations that facilitate their maintaining employment.

METHOD

Qualitative phenomenological approach was used to echo women's subjective perceptions and experiences representing their daily interactions in their workplace. In-depth interviews were conducted with eleven tertiary-educated employed women (M = 33.5; SD = 6.61 years), diagnosed with ADHD and the transcripts were analyzed by three researchers, using the qualitative phenomenological approach.

RESULTS

Most interviewed women with ADHD described interactions with their workplace as confusing, overwhelming, and chaotic. They perceived their ADHD as a significant obstacle to success in employment that also conferred some advantages. Three interview themes are explored here (1) challenges in coping with job demands and the workplace, including the disclosure dilemma; (2) personal coping strategies; (3) useful accommodations.

CONCLUSIONS

For the women interviewed, employment was important for their self-identity, beyond simply making a living. Their experiences indicate impaired executive functioning and inhibition and sensory sensitivity, consistently with theoretical models for ADHD. They identified gender-specific issues, such as using medication during pregnancy, which led them to seek for non-pharmacological coping mechanisms. They contributed practical knowledge regarding employee-led adaptations and employer-provided workplace accommodations.

Sleep-Dependent Consolidation of Rewarded Behavior Is Diminished in Children with Attention Deficit Hyperactivity Disorder and a Comorbid Disorder of Social Behavior

Children suffering from attention-deficit hyperactivity disorder (ADHD) often also display impaired learning and memory. Previous research has documented aberrant reward processing in ADHD as well as impaired sleep-dependent consolidation of declarative memory. We investigated whether sleep also fosters the consolidation of behavior learned by probabilistic reward and whether ADHD patients with a comorbid disorder of social behavior show deficits in this memory domain, too. A group of 17 ADHD patients with comorbid disorders of social behavior aged 8–12 years and healthy controls matched for age, IQ, and handedness took part in the experiment. During the encoding task, children worked on a probabilistic learning task acquiring behavioral preferences for stimuli rewarded most often. After a 12-hr retention interval of either sleep at night or wakefulness during the day, a reversal task was presented where the contingencies were reversed. Consolidation of rewarded behavior is indicated by greater resistance to reversal learning. We found that healthy children consolidate rewarded behavior better during a night of sleep than during a day awake and that the sleep-dependent consolidation of rewarded behavior by trend correlates with non-REM sleep but not with REM sleep. In contrast, children with ADHD and comorbid disorders of social behavior do not show sleep-dependent consolidation of rewarded behavior. Moreover, their consolidation of rewarded behavior does not correlate with sleep. The results indicate that dysfunctional sleep in children suffering from ADHD and disorders of social behavior might be a crucial factor in the consolidation of behavior learned by reward.

Prevalence of attention deficit/hyperactivity disorder among children and adolescents in China: a systematic review and meta-analysis

BACKGROUND

Attention deficit/hyperactivity disorder (ADHD), the most common childhood neurobehavioural disorder, can produce a series of negative effects on children, adolescents, and even adults as well as place a serious economic burden on families and society. However, the prevalence of ADHD is not well understood in China. The goal of this study was to estimate the pooled prevalence of ADHD among children and adolescents in China using a systematic review and meta-analysis.

METHODS

A systematic literature search was conducted in PubMed, Web of Science, MEDLINE, CNKI, Wanfang, Weipu and CBM databases, and relevant articles published from inception to March 1, 2016, that provided the prevalence of ADHD among children and adolescents in China were reviewed. The risk of bias in individual studies was assessed using the Risk of Bias Tool for prevalence studies. Pooled-prevalence estimates were calculated with a random-effects model. Sources of heterogeneity were explored using subgroup analyses.

RESULTS

Sixty-seven studies with a total of 275,502 individuals were included in this study. The overall pooled-prevalence of ADHD among children and adolescents in China was 6.26% (95% CI: 5.36-7.22%) with significant heterogeneity (I2 = 99.0%, P < 0.001). The subgroup analyses showed that, the variables "geographic location" and "source of information" partially explained of the heterogeneity in this study (P < 0.05). The prevalence of ADHD-I was the highest of the subtypes, followed by ADHD-HI and ADHD-C.

CONCLUSIONS

The prevalence of ADHD among children and adolescents in China is generally consistent with the worldwide prevalence and shows that ADHD affects quite a large number of people under 18 years old. However, a nationwide study is needed to provide more accurate estimations.

Preschool hyperactivity specifically elevates long-term mental health risks more strongly in males than females: a prospective longitudinal study through to young adulthood

Evidence of continuities between preschool hyperactivity and adult mental health problems highlights the potential value of targeting early identification and intervention strategies. However, specific risk factors are currently unclear. This large-scale prospective longitudinal study aimed to identify which hyperactive preschoolers are at the greatest long-term risk of poor mental health. One hundred and seventy children (89 females) rated as hyperactive by their parents, and 88 non-hyperactive controls (48 females) were identified from a community sample of 4215 3-year-olds. Baseline data relating to behavioral/emotional problems and background characteristics were collected. Follow-up mental health and functional impairment outcomes were collected between 14 and 25 years of age. At age 3 years, males and females in the hyperactive group had similarly raised levels of hyperactivity and other behavior problems. In adolescence/young adulthood, these individuals showed elevated symptoms of ADHD, conduct disorder, mood disorder, anxiety and autism, as well as functional impairment. Preschool hyperactivity was strongly predictive of poor adolescent/adult outcomes for males across domains with effects being specifically driven by hyperactivity. For females, the effects of preschool hyperactivity were smaller and dropped to non-significant levels when other preschool problems were taken into account. Environmental risk factors also differed between the sexes, although these may also have been mediated by genetic risk. In conclusion, these results demonstrate marked sex differences in preschool predictors of later adolescent/adult mental health problems. Future research should include a measure of preschool inattention as well as hyperactivity. The findings highlight the potential value of tailored approaches to early identification strategies.

Potential role of pre- and postnatal testosterone levels in attention-deficit/hyperactivity disorder: is there a sex difference?

OBJECTIVE

Both prenatal testosterone (T) exposure and postnatal T levels have been associated with developing neural circuitry and behavioral systems. This study examined the potential correlation between pre- and postnatal T levels and behavioral and neurocognitive profiles of children with attention-deficit/hyperactivity disorder (ADHD).

METHODS

Two hundred ADHD patients with a mean age of 8.7±2.0 years (158 boys and 42 girls) were recruited. The ratio of the length of the right index finger (2D) to that of the right ring finger (4D) (2D/4D ratio) served as a surrogate of prenatal T exposure, and postnatal T was determined using salivary T concentration. Behavioral symptoms were evaluated using the Swanson, Nolan, and Pelham - Version IV Scale for ADHD (SNAP-IV). Neurocognitive function was assessed using the Wechsler Intelligence Scale for Children - Fourth Edition (WISC-IV) and Conners' Continuous Performance Test (CPT).

RESULTS

Lower 2D/4D ratios were associated with comorbid disruptive behavior disorders (t=2.15, P=0.033) in all participants. Among the boys with ADHD, neither 2D/4D ratios nor salivary T levels were associated with behavioral symptoms or neurocognitive function. Among the girls with ADHD, the salivary T level was positively correlated with the Perceptual Reasoning Index of the WISC-IV (r=0.48, P=0.001) and the Confidence Index (r=0.37, P=0.017) and Omission Errors of the CPT (r=0.62, P<0.001).

CONCLUSION

Findings suggest that a higher prenatal T exposure is associated with a greater risk of developing disruptive behavior disorders, and T may exert differential neurocognitive effects between boys and girls with ADHD. However, the neurobiological mechanisms of T involved in the pathogenesis of ADHD warrant further investigation.

Subthreshold and threshold attention deficit hyperactivity disorder symptoms in childhood: psychosocial outcomes in adolescence in boys and girls

OBJECTIVE

To examine the association between different levels of childhood attention deficit hyperactivity disorder (ADHD) symptoms and sex differences in psychosocial outcomes during adolescence.

METHOD

Swedish children (n = 4635) were screened for neuropsychiatric symptoms at age 9 or 12. ADHD symptoms were divided into three levels: screen-negative, screen-intermediate, and screen-positive. At follow-up (age 15), parents and teenagers filled out questionnaires regarding (i) hyperactivity/inattention, (ii) peer problems, (iii) school problems, (iv) internalizing problems, (v) antisocial behaviour, (vi) alcohol misuse, and (vii) drug misuse. All outcomes were controlled for symptoms of diagnostic categories other than ADHD.

RESULTS

Increasing levels of ADHD symptoms in childhood were associated with higher proportions of adolescents who displayed negative psychosocial outcomes. More girls than boys reported internalizing problems (all levels) and risky drug use (screen-intermediate and screen-positive only). More boys reported antisocial behaviour at the screen-negative and screen-intermediate levels, but at the screen-positive level, similar proportions of girls and boys displayed antisocial behaviour.

CONCLUSION

The findings support the view that ADHD symptoms, as well as their negative outcomes, are dimensionally distributed in the population and that adolescent girls and boys display different risk profiles. The findings confirm that ADHD symptoms are associated with higher risk of drug misuse in girls.

Attention-deficit/hyperactivity disorder casts a long shadow: findings from a population-based study of adult women with self-reported ADHD

BACKGROUND

To develop a sociodemographic and health profile of women with self-reported attention deficit/hyperactivity disorder (ADHD) in comparison to women without.

METHODS

Chi-square tests and logistic regression analyses were conducted on data from the nationally representative Canadian Community Health Survey-Mental Health (2012) comparing 107 women aged 20 to 39 years (inclusive) with ADHD to 3801 without ADHD. Depression, generalized anxiety disorder and substance abuse were measured using the WHO-CIDI.

RESULTS

Women with ADHD had triple the prevalence of insomnia, chronic pain, suicidal ideation, childhood sexual abuse and generalized anxiety disorder and double the prevalence of substance abuse, current smoking, depressive disorders, severe poverty and childhood physical abuse in comparison with women without ADHD (all P < 0.001). Even after adjustments for age, race, education and income, women with ADHD had substantially higher odds of a wide range of problems.

CONCLUSION

Our results suggest that women with ADHD are particularly vulnerable to early adversities, health and mental health problems.