Health care and societal costs of the management of children and adolescents with attention-deficit/hyperactivity disorder in Spain: a descriptive analysis

Methods used to account for caregivers' sex and gender within studies examining the financial burden of caregivers of children and adolescents : Results from a scoping review

Background

Interest in the financial burden of informal caregivers has been growing. Unfortunately, it remains unclear which method(s) should be used when quantifying this burden.

Purpose

We conducted a scoping review aimed at identifying which methods have been used to conduct such work and quantified their performance. We were also interested in examining how sex and gender considerations were considered within selected studies.

Data Sources

Using a standardized approach, we identified studies published between 2012 and 2022 that aimed to document the financial burden of caregivers to child and adolescent patients. Our search strategy was applied to the MEDLINE, Embase, CINHAL, and Academic Search Premier databases.

Study Selection

Manuscript selection was performed by pairs of reviewers.

Data Extraction

Data extraction was performed by one reviewer with a second reviewer performing quality control. Results were reported using a narrative approach.

Data Synthesis

We identified 9801 unique citations, of which 200 were included in our review. Selected studies covered various disease area (eg, infection/parasitic diseases [n = 31, 16%]) and included quantitative (n = 180, 90%), qualitative (n = 4, 2%) and mixed study designs (n = 16, 8%). Most studies (n = 182, 91%) used questionnaires/surveys, either alone or in combination with other methods, to assess caregivers' financial burden. Less than half (n = 93, 47%) of studies reported on caregivers' sex and none reported on their gender.

Conclusion

We conducted an unrestricted review of published studies examining caregiver's financial burden which allowed us to identify general methodological trends observed in this literature. We believe this work may help improve future studies focusing on this important issue.

The socioeconomic burden of adult attention-deficit/hyperactivity disorder in Spain

Introduction

The symptoms of attention-deficit/hyperactivity disorder (ADHD) in adults highly interfere with function in multiple dimensions, increasing the economic burden associated with ADHD. The aim of this study was to explore the impact of ADHD in Spanish adults and estimate the associated economic burden within the healthcare, social, economic, and legal domains.

Methods

An economic model was developed from a social perspective using a bottom-up approach, based on the scientific literature and a multidisciplinary expert group.

Results

The cost incurred per diagnosed adult patient with ADHD included an annual cost of €15,652 and a one-time cost of €7,893 (3,035 M€ and 1,531 M€ for Spain, respectively). Regarding the annual cost, 50% was attributed to costs within the economic domain, of which 53% were work-absenteeism-related. Moreover, 28% was attributed to costs within the social domain, of which 74% were substance-abuse-related. Regarding the one-time cost, 52% was attributed to costs within the healthcare domain, of which approximately 50% were hospitalization-related costs. Moreover, 42% was attributed to costs within the legal domain, of which 62% were imprisonment-related costs.

Conclusions

This is the first report on the socioeconomic burden of ADHD in Spanish adults, shedding light on the large burden that adult ADHD poses on the healthcare system and society at large, as symptoms have been shown to impact almost every aspect of life. This is particularly important for undiagnosed/untreated patients with ADHD in Spain, as appropriate treatments have shown positive results in these areas and may reduce its associated socioeconomic burden.

Facial emotion recognition in children and youth with attention-deficit/hyperactivity disorder and irritability

The ability to recognize emotions evident in people's faces contributes to social functioning and might be affected by ADHD and irritability. Given their high co-occurrence, we examined the relative contribution of ADHD and irritability to facial emotion recognition (FER). We hypothesized that irritability but not ADHD traits would predict increased likelihood of misrecognizing emotions as negative, and that FER performance would explain the association of ADHD and irritability traits with social skills. FER was measured using the Reading the Mind in the Eyes Test (RMET) in children (6-14 years old) referred for ADHD assessment (n = 304) and healthy controls (n = 128). ADHD, irritability and social skills were measured using parent ratings. We used repeated measure logistics regression, comparing the effects across emotion valence of images (i.e., neutral/positive/negative). High irritability but not ADHD diagnosis predicted lower RMET accuracy. ADHD traits predicted lower RMET accuracy in younger but not older participants, whereas irritability predicted poorer accuracy at all ages. ADHD traits predicted lower RMET accuracy across all emotion valences, whereas irritability predicted increased probability of misrecognizing neutral and positive but not negative emotions. Irritability did not increase the probability for erroneously recognizing emotions as negative. ADHD and irritability traits fully explained the association between RMET and social skills. ADHD and irritability traits might impact the ability to identify emotions portrayed in faces. However, irritability traits appear to selectively impair recognition of neutral and positive but not negative emotions. ADHD and irritability are important when examining the link between FER and social difficulties.

Attention deficit hyperactivity disorder: Insights into underfunding in the private healthcare sector in South Africa

Background

Although the prevalence of attention deficit hyperactivity disorder (ADHD) has remained stable, the number of patients diagnosed with ADHD has increased in recent years owing to increased awareness. Despite this increase, medical schemes in South Africa have not improved their funding models for this condition.

Aim

The study aimed to provide an account of the funding that medical schemes provisioned for treating ADHD in South Africa during 2022.

Setting

All the South African medical schemes that were registered with the Council of Medical Schemes during 2022 (n = 72) and all their listed options were evaluated (n = 279).

Methods

The study analysed secondary data published on the medical schemes' websites in the public domain. Statistical minimum, average, maximum and correlation analyses were performed using Excel version 16.58.

Results

Attention deficit hyperactivity disorder is not regarded as a prescribed minimum benefit (PMB) condition and therefore each medical scheme used its own approach to providing its beneficiaries with some or no benefits for ADHD. It was evident that ADHD was underfunded and lacked structured or standardised funding approaches.

Conclusion

Attention deficit hyperactivity disorder is underfunded in the private healthcare sector in South Africa. Better funding models are needed or ADHD needs to be registered as a PMB condition.

Contribution

Findings from this study highlight the urgency for structured and sufficient ADHD-specific funding by medical schemes. Considerations based on these findings may be applied in the National Health Insurance and in other countries around the world.

Differential costs for the non-adult ADHD population in Catalonia

Attention-Deficit/Hyperactivity Disorder (ADHD) is young children's most common mental health disorder. We aim to provide causal estimates of the differential costs for the non-adult population with ADHD. We used longitudinal administrative data covering the non-adult population over five years and different healthcare providers (general practitioners, hospitalisations and emergency departments, visits to mental healthcare centres-day-care or hospitals) of 1,101,215 individuals in Catalonia (Spain). We also include the consumption of pharmaceuticals and cognitive therapies. We instrumented ADHD diagnosis by the probability of being diagnosed by the most visited healthcare provider based on individual monthly visits to the provider in which this visit was related to ADHD and the density of professionals in the different mental health providers. After using matching procedures to include a proper control group, we estimated two-part and finite mixture models. Our results indicate that ADHD children and adolescents displayed 610€ higher annual health direct costs compared to not diagnosed counterparts. We provide average costs disentangling the sample by age boundaries, gender, and comorbidities to offer values for cost-effective analyses and incremental costs after diagnosis, which is around 400€. A significant differential annual direct health cost for the non-adult population with ADHD is determined, which will be helpful for cost-effectiveness analysis and complete cost-of-illness studies.

Prenatal Exposure to Air Pollutants and Attentional Deficit Hyperactivity Disorder Development in Children: A Systematic Review

Up to 9.5% of the world's population is diagnosed with attention deficit/hyperactivity disorder (ADHD), making it one of the most common childhood disorders. Air pollutants could be considered an environmental risk condition for ADHD, but few studies have specifically investigated the effect of prenatal exposure. The current paper reviews the studies conducted on the association between prenatal air pollutants (PM, NO_x, SO₂, O₃, CO and PAH) and ADHD development in children. From the 890 studies searched through PubMed, Google Scholar, Scopus, and Web of Science, 15 cohort studies met the inclusion criteria. NOS and WHO guidelines were used for quality and risk of bias assessment. The accumulative sample was 589,400 of children aged 3-15 years. Most studies reported an association between ADHD symptoms and prenatal PAH and PM exposure. Data available on NO₂ and SO₂ were inconsistent, whereas the effect of CO/O₃ is barely investigated. We observed heterogeneity through an odd ratio forest plot, and discrepancies in methodologies across the studies. Eight of the fifteen studies were judged to be of moderate risk of bias in the outcome measurement. In a nutshell, future studies should aim to minimize heterogeneity and reduce bias by ensuring a more representative sample, standardizing exposure and outcome assessments.

Gestational organophosphate ester exposure and preschool attention-deficit/hyperactivity disorder in the Norwegian Mother, Father, and Child cohort study

BACKGROUND

Attention-deficit/hyperactivity-disorder (ADHD) is a leading neurodevelopmental disorder in children worldwide; however, few modifiable risk factors have been identified. Organophosphate esters (OPEs) are ubiquitous chemical compounds that are increasingly prevalent as a replacement for other regulated chemicals. Current research has linked OPEs to neurodevelopmental deficits. The purpose of this study was to assess gestational OPE exposure on clinically-assessed ADHD in children at age 3 years.

METHODS

In this nested case-control study within the Norwegian Mother, Father, and Child Cohort study, we evaluated the impact of OPE exposure at 17 weeks' gestation on preschool-age ADHD. Between 2007 and 2011, 260 ADHD cases were identified using the Preschool Age Psychiatric Assessment and compared to a birth-year-stratified control group of 549 children. We categorized bis(2-butoxyethyl) phosphate (BBOEP) and bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) as values < limit of detection (LOD) (BBOEP N = 386, BDCIPP N = 632), ≥LOD but < limit of quantification (LOQ) (BBOEP N = 413; BDCIPP N = 75), or above LOQ (BBOEP N = 70; BDCIPP N = 102). Diphenyl phosphate (DPhP) and di-n-butyl phosphate (DnBP) were categorized as quartiles and also modeled with a log10 linear term. We estimated multivariable adjusted odds ratios (ORs) using logistic regression and examined modification by sex using an augmented product term approach.

RESULTS

Mothers in the 3rd DnBP quartile had 1.71 times the odds of having a child with ADHD compared to the 1st quartile (95%CI: 1.13, 2.58); a similar trend was observed for log10 DnBP and ADHD. Mothers with BDCIPP ≥ LOD but < LOQ had 1.39 times the odds of having a child with ADHD compared to those with BDCIPP < LOD (95%CI: 0.83, 2.31). Girls had lower odds of ADHD with increasing BBOEP exposure (log10 OR: 0.55 (95%CI: 0.37, 0.93), however boys had a weakly increased odds (log10 OR: 1.25 (95%CI: 0.74, 2.11) p-interaction = 0.01].

CONCLUSIONS

We found modest increased odds of preschool ADHD with higher DnBP and BDCIPP exposure.

Different functional alteration in attention-deficit/hyperactivity disorder across developmental age groups: A meta-analysis and an independent validation of resting-state functional connectivity studies

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a highly complex and heterogeneous disorder. Abnormal brain connectivity in ADHD might be influenced by developmental ages which might lead to the lacking of significant spatial convergence across studies. However, the developmental patterns and mechanisms of ADHD brain connectivity remain to be fully uncovered.

METHODS

In the present study, we searched PubMed, Scopus, Web of Science, and Embase for seed-based whole-brain resting-state functional connectivity studies of ADHD published through October 12th, 2020. The seeds meeting inclusion criteria were categorized into the cortex group and subcortex group, as previous studies suggested that the cortex and subcortex have different temporal patterns of development. Activation likelihood estimation meta-analysis was performed to investigate the abnormal connectivity in different age groups (all-age group, younger: <12 years, older: ≥12 years). Moreover, significant convergence of reported foci was used as seeds for validation with our independent dataset.

RESULTS

As with previous studies, scarce results were found in the all-age group. However, we found that the younger group consistently exhibited hyper-connectivity between different parts of the cortex and left middle frontal gyrus, and hypo-connectivity between different parts of the cortex and left putamen/pallidus/amygdala. Whereas, the older group (mainly for adults) showed hyper-connectivity between the cortex and right precuneus/sub-gyral/cingulate gyrus. Besides, the abnormal cortico-cortical and cortico-subcortical functional connectivity in children, and the abnormal cortico-cortical functional connectivity in adults were verified in our independent dataset.

CONCLUSION

Our study emphasizes the importance of developmental age effects on the study of brain networks in ADHD. Further, we proposed that cortico-cortical and cortico-subcortical connectivity might play an important role in the pathophysiology of children with ADHD, while abnormal cortico-cortical connections were more important for adults with ADHD. This work provided a potential new insight to understand the neurodevelopmental mechanisms and possible clinical application of ADHD.

The Cost of Neurodevelopmental Disability: Scoping Review of Economic Evaluation Methods

The provision of effective care models for children with neurodevelopmental delay or disability can be challenging in resource constrained healthcare systems. Economic evaluations have an important role in informing resource allocation decisions. This review systematically examined the scope and methods of economic models evaluating interventions for supporting neurodevelopment among children with common neurodevelopmental disorders and identified methods of economic models and presented policy implications. This scoping review employed the Arksey and O'Malley framework and aligned with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Four electronic databases were systematically searched to identify eligible model-based economic evaluations of neurodevelopmental care models published since 2000. The Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist was used to assess quality of reporting. Data were systematically extracted, tabulated, and qualitatively synthesised across diagnostic categories. Searches identified 1431 unique articles. Twelve studies used a decision analytic model to evaluate care for neurodevelopmental disorders and were included in the review. Included studies focused on attention-deficit/hyperactivity disorder (ADHD, n=6), autism spectrum disorder (ASD, n=3), cerebral palsy (n=2), and dyslexia (n=1). The most used decision analytic modelling approach was a Markov model (n=6), followed by a decision tree (n=3), and a combination of decision tree and Markov model (n=3). Most studies (n=7) adopted a societal perspective for reporting costs. None of the reviewed studies modelled impact on families and caregivers. Four studies reported cost-savings, three identified greater quality of life, and three identified cost increases.

Eating Patterns and Dietary Interventions in ADHD: A Narrative Review

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common neurodevelopmental disorders in childhood, affecting ~7% of children and adolescents. Given its adverse health outcomes and high healthcare and societal costs, other treatment options beyond pharmacotherapy have been explored. Case-control studies have shown that dietary patterns may influence the risk of ADHD, and specific dietary interventions have been proposed as coadjuvant treatments in this disorder. These include nutritional supplements, gut microbiome-targeted interventions with biotics, and elimination diets. The purpose of this review is to examine which dietary patterns are most associated with ADHD and to summarize the existing evidence for the clinical use of dietary interventions. The literature showed that non-healthy dietary patterns were positively associated with ADHD, whereas healthy patterns were negatively associated. As for nutritional supplements, only vitamin D and vitamin D + magnesium appeared to improve ADHD symptoms when baseline levels of vitamin D were insufficient/deficient. Regarding biotics, evidence was only found for Lactobacillus rhamnosus GG and for multi-species probiotic supplementation. Elimination diets have scarce evidence and lead to nutritional deficiencies, so caution is advised. Overall, more robust scientific evidence is required for these dietary interventions to be implemented as part of ADHD therapy.

Family, personal, parental correlates and behavior disturbances in school-aged boys with attention-deficit/hyperactivity disorder (ADHD): a cross-sectional study

BACKGROUND

To evaluate the relationship among family, personal, parental correlates, and behavioral disturbances in boys with attention-deficit/hyperactivity disorder (ADHD).

METHODS

We performed a hospital-based cross-sectional study. School-aged boys who first visited the hospital between 2000 and 2011 with ADHD were identified. Through medical records review, demographic information, family characteristics, personal characteristics, parental characteristics, and the Child Behavior Checklist (CBCL) collected during the first outpatient visit were retrieved. A T-score higher than 63 in the internalizing or externalizing subscale of the CBCL indicated severe behavioral disturbances in each domain. Multivariable logistic regression was used to evaluate the relationship between the correlates and behavioral disturbances. Eligible patients were further classified into groups without behavioral disturbance, with either only severe internalizing or only severe externalizing behaviors, or with both behaviors. Multivariable ordinal logistic regression was used to investigate the association between the correlates and the number of types of behavioral disturbances.

RESULTS

A total of 1855 boys with ADHD were included. In the multivariable logistic regression, family factors, including being first-born, living in a family not with both parents, and family history of mental disorder, were associated with severe internalizing and externalizing behaviors. Personal factors, including prenatal complications, perinatal complications, and medical and psychiatric comorbidities, were associated with severe internalizing behaviors, but only prenatal complications and medical comorbidities were associated with severe externalizing behaviors. Parental factors were only associated with severe externalizing behaviors. A higher paternal education level had a protective effect, but younger motherhood increased the risk. In ordinal logistic regression, these factors were also associated with more types of behavioral disturbances.

CONCLUSIONS

Multiple factors are related to behavioral disturbances in ADHD. Our study reported the association among family, personal, parental factors, severe internalizing behavior, severe externalizing behavior, and number of behavioral disturbances in boys with ADHD. However, the impacts differed as the behavior phenotypes varied. Further research is needed to better understand the heterogeneity of ADHD behavior.

Long-Term Treatment With Extended-Release Methylphenidate Treatment in Children Aged 4 to <6 Years

OBJECTIVE

To investigate long-term (12-month) safety and symptom control of extended-release methylphenidate (MPH-MLR) in children aged 4 to <6 years after treatment optimization.

METHOD

A total of 90 children aged 4 to <6 years with attention-deficit/hyperactivity disorder (ADHD) were enrolled from 2 MPH-MLR studies. Treatment-emergent adverse events (TEAEs) and ADHD symptom control were assessed in the safety population (n = 89) and modeled with mixed model analyses.

RESULTS

Most TEAEs (89.9%) were rated by investigators as of mild or moderate severity. One serious AE was reported (unrelated to study drug). Ten children discontinued because of TEAEs. Two discontinued because of weight loss; no significant increase in the rate of underweight children from baseline to endpoint was observed. Overall, 18% lost weight and 18% reported decreased appetite. Weight and height z scores and obesity rates decreased significantly from baseline to endpoint. Insomnia was reported (9%); none of these children discontinued. Sleep quality did not change significantly. Hypertension was reported (6.7%); none of these children dropped out. Diastolic, but not systolic, blood pressure increased significantly during the follow-up. Control of ADHD symptoms was maintained throughout follow-up.

CONCLUSION

These data contribute to the understanding of the long-term safety of an extended-release stimulant in children 4 to <6 years of age. The observed risk of a TEAE-related discontinuation was ∼11%. TEAEs were not dose related, and most were of mild to moderate severity. Symptom control was maintained through the year-long study.

CLINICAL TRIAL REGISTRATION INFORMATION

A 12-Month Open Label Safety Study of Aptensio XR® in Children Ages 4-5 Years Diagnosed With ADHD (EF004); https://clinicaltrials.gov; NCT02677519.

The cost-effectiveness of treatments for attention deficit-hyperactivity disorder and autism spectrum disorder in children and adolescents: a systematic review

Economic evaluations can help decision makers identify what services for children with neurodevelopmental disorders provide best value-for-money. The aim of this paper is to review the best available economic evidence to support decision making for attention deficit-hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in children and adolescents. We conducted a systematic review of economic evaluations of ADHD and ASD interventions including studies published 2010-2020, identified through Econlit, Medline, PsychINFO, and ERIC databases. Only full economic evaluations comparing two or more options, considering both costs and consequences were included. The quality of the studies was assessed using the Drummond checklist. We identified ten studies of moderate-to-good quality on the cost-effectiveness of treatments for ADHD and two studies of good quality of interventions for ASD. The majority of ADHD studies evaluated pharmacotherapy (n = 8), and two investigated the economic value of psychosocial/behavioral interventions. Both economic evaluations for ASD investigated early and communication interventions. Included studies support the cost-effectiveness of behavioral parenting interventions for younger children with ADHD. Among pharmacotherapies for ADHD, different combinations of stimulant/non-stimulant medications for children were cost-effective at willingness-to-pay thresholds reported in the original papers. Early intervention for children with suspected ASD was cost-effective, but communication-focused therapy for preschool children with ASD was not. Prioritizing more studies in this area would allow decision makers to promote cost-effective and clinically effective interventions for this target group.

Review of barriers and interventions to promote treatment engagement for pediatric attention deficit hyperactivity disorder care

Attention deficit hyperactivity disorder (ADHD) is a common and impairing behavioral health disorder, impacting over 5% of children worldwide. There are multiple evidence-based pharmacological and psychosocial treatments for ADHD, and greater service utilization is associated with improved acute and long-term outcomes. However, long-term outcomes are suboptimal as multimodal treatments are often not accessed and most care ends prematurely. This narrative review discusses barriers to engagement for children and adolescents with ADHD and their families as well as interventions to overcome these barriers. Families face a variety of structural and attitudinal barriers, ranging from cost and access to stigma and low self-efficacy to successfully implement change. There are multiple interventions that may enhance engagement with ADHD care including psychoeducation, integration of behavioral services in general medical settings, telehealth as well as specific adaptations to existing ADHD treatments, such as the use of motivational interviewing or shared decision making. Integration of behavioral health into general medical settings and telehealth have been found in controlled studies to increase access by reducing both structural and attitudinal barriers. Adding motivational interviewing, shared decision making and other engagement interventions to evidence-based ADHD treatments has been found to reduce attitudinal barriers that translates into improved participation and satisfaction while enhancing outcomes. However, little is known about how to promote extended engagement with ADHD services even though a chronic care model for ADHD is recommended.

Elevated risk of attention deficit hyperactivity disorder (ADHD) in Japanese children with higher genetic susceptibility to ADHD with a birth weight under 2000 g

BACKGROUND

Both genetic and pre- and perinatal factors, including birth weight, have been implicated in the onset of attention deficit hyperactivity disorder (ADHD) traits among children. This study aimed to elucidate to what extent the genetic risk of ADHD moderates the association between birth weight and ADHD traits among Japanese children.

METHODS

We conducted a longitudinal birth cohort study (Hamamatsu Birth Cohort for Mother and Children Study) to investigate the association of genetic risk for ADHD and low birth weight with ADHD traits among Japanese children. Out of 1258 children, we included 796 who completed follow-ups at 8 to 9 years of age. Birth weight was categorized as <2000 g, 2000-2499 g, and ≥2500 g. Polygenic risk score for ADHD was generated using the summary data of a large-scale genome-wide association study. The Rating Scale IV (ADHD-RS) assessed ADHD traits (inattention and hyperactivity/impulsivity) based on parental reports. Following previous studies, sex, birth order of the child, gestational age at birth, mother's age at delivery, educational attainment, pre-pregnancy body mass index, pre-pregnancy or during pregnancy smoking status, alcohol consumption during pregnancy, father's age, education, and annual family income were considered as covariates. Multivariable negative binomial regression was applied to evaluate the association between birth weight and ADHD traits, while adjusting for potential covariates. The interaction term between birth weight categories and binary polygenic risk was added to the model.

RESULTS

Birth weight of 2000-2499 g was not associated with ADHD traits. Birth weight under 2000 g was significantly associated with both inattention and hyperactivity. When accounting for higher and lower genetic risk for ADHD, only those with higher genetic risk and birth weight < 2000 g were associated with inattention (rate ratio [RR] 1.56, 95% CI 1.07-2.27) and hyperactivity (RR 1.87, 95% CI 1.14-3.06).

CONCLUSIONS

Birth weight under 2000 g, together with the genetic risk of ADHD, contributes to higher levels of ADHD traits among Japanese children aged 8 to 9 years. The suggested association between low birth weight and ADHD is confined to children with a genetic susceptibility to ADHD, indicating the relevance of genetic-environmental interactions in the etiology.

Gestational Phthalate Exposure and Preschool Attention Deficit Hyperactivity Disorder in Norway

Supplemental Digital Content is available in the text.

Prenatal phthalate exposure has been linked to altered neurobehavioral development in both animal models and epidemiologic studies, but whether or not these associations translate to increased risk of neurodevelopmental disorders is unclear. We used a nested case-cohort study design to assess whether maternal urinary concentrations of 12 phthalate metabolites at 17 weeks gestation were associated with criteria for Attention Deficit Hyperactivity Disorder (ADHD) classified among 3-year-old children in the Norwegian Mother, Father and Child Cohort Study (MoBa). Between 2007 and 2011, 260 children in this substudy were classified with ADHD using a standardized, on-site clinical assessment; they were compared with 549 population-based controls. We modeled phthalate levels both linearly and by quintiles in logistic regression models adjusted for relevant covariates and tested for interaction by child sex. Children of mothers in the highest quintile of di-iso-nonyl phthalate (∑DiNP) metabolite levels had 1.70 times the odds of being classified with ADHD compared with those in the lowest quintile (95% confidence interval [CI] = 1.03 to 2.82). In linear models, there was a trend with the sum of di-2-ethylhexyl phthalate metabolites (∑DEHP); each natural log-unit increase in concentration was associated with 1.22 times the odds of ADHD (95% CI = 0.99 to 1.52). In boys, but not girls, mono-n-butyl phthalate exposure was associated with increased odds of ADHD (odds ratio [OR] 1.42; 95% CI = 1.07 to 1.88). Additional adjustment for correlated phthalate metabolites attenuated estimates. These results suggest gestational phthalate exposure may impact the behavior of children as young as 3 years.

Do Costs in the Education Sector Matter? A Systematic Literature Review of the Economic Impact of Psychosocial Problems on the Education Sector

BACKGROUND

Psychosocial (e.g., anxiety or behavior) problems lead to costs not only in the healthcare sector but also in education and other sectors. As psychosocial problems develop during the critical period of establishing educational trajectories, education costs are particularly relevant in the context of psychosocial problems among children and adolescents.

OBJECTIVES

This study aimed to gain insights into the methods used for the inclusion of education costs in health economics studies and into the proportion of the education costs in relation to the total costs associated with a condition or an intervention.

METHODS

We systematically searched the PubMed, Embase, SSCI, CINAHL, PsycINFO, ERIC, and Econlit databases in August 2019 for economic evaluations of mental health, psychosocial and educational interventions, and cost-of-illness studies of mental, behavioral, and neurodevelopmental disorders conducted from a societal perspective in populations of children and adolescents. An additional search was conducted in February 2021 to update the review.

RESULTS

In total, 49 articles were included in the analysis. The most common cost items were special education, school absenteeism, and various educational professionals (educational psychologist). A variety of methods were employed for the identification, measurement, and/or valuation of education costs. The proportion of education costs to the total costs of condition/intervention ranged from 0 to 67%, with the mean being 18.5%.

DISCUSSION

Since education costs can constitute a significant proportion of the total costs of an intervention or condition, including them in health economics studies might be important in informing optimal resource allocation decisions. Although various methods are available for including education costs in health economics studies, further research is needed to develop evidence-based methods for producing comparable estimates.

Genetic variations influence brain changes in patients with attention-deficit hyperactivity disorder

Attention-deficit hyperactivity disorder (ADHD) is a neurological and neurodevelopmental childhood-onset disorder characterized by a persistent pattern of inattentiveness, impulsiveness, restlessness, and hyperactivity. These symptoms may continue in 55-66% of cases from childhood into adulthood. Even though the precise etiology of ADHD is not fully understood, it is considered as a multifactorial and heterogeneous disorder with several contributing factors such as heritability, auxiliary to neurodevelopmental issues, severe brain injuries, neuroinflammation, consanguineous marriages, premature birth, and exposure to environmental toxins. Neuroimaging and neurodevelopmental assessments may help to explore the possible role of genetic variations on ADHD neuropsychobiology. Multiple genetic studies have observed a strong genetic association with various aspects of neuropsychobiological functions, including neural abnormalities and delayed neurodevelopment in ADHD. The advancement in neuroimaging and molecular genomics offers the opportunity to analyze the impact of genetic variations alongside its dysregulated pathways on structural and functional derived brain imaging phenotypes in various neurological and psychiatric disorders, including ADHD. Recently, neuroimaging genomic studies observed a significant association of brain imaging phenotypes with genetic susceptibility in ADHD. Integrating the neuroimaging-derived phenotypes with genomics deciphers various neurobiological pathways that can be leveraged for the development of novel clinical biomarkers, new treatment modalities as well as therapeutic interventions for ADHD patients. In this review, we discuss the neurobiology of ADHD with particular emphasis on structural and functional changes in the ADHD brain and their interactions with complex genomic variations utilizing imaging genetics methodologies. We also highlight the genetic variants supposedly allied with the development of ADHD and how these, in turn, may affect the brain circuit function and related behaviors. In addition to reviewing imaging genetic studies, we also examine the need for complementary approaches at various levels of biological complexity and emphasize the importance of combining and integrating results to explore biological pathways involved in ADHD disorder. These approaches include animal models, computational biology, bioinformatics analyses, and multimodal imaging genetics studies.

Global Economic Burden of Attention-Deficit/Hyperactivity Disorder: A Systematic Review

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common mental disorders affecting children and adults. Previous systematic reviews have provided estimates of ADHD-associated costs but were limited to the USA and Europe.

OBJECTIVES

This study aimed to systematically summarise all global evidence on the economic burden of ADHD.

METHODS

A systematic search for published studies on costs of ADHD was conducted in EconLit, EMBASE, PubMed, ERIC, and PsycINFO. Additional literature was identified by searching the reference lists of eligible studies. The quality of the studies was assessed using the Larg and Moss checklist.

RESULTS

This review included 44 studies. All studies were conducted in high-income countries and were limited to North America and Europe except for four studies: two in Asia and two in Australia. Most studies were retrospective and undertook a prevalence-based study design. Analysis revealed a substantial economic impact associated with ADHD. Estimates based on total costs ranged from $US831.38 to 20,538 for per person estimates and from $US356 million to 20.27 billion for national estimates. Estimates based on marginal costs ranged from $US244.15 to 18,751.00 for per person estimates and from $US12.18 million to 141.33 billion for national estimates. Studies that calculated economic burden across multiple domains of direct, indirect, and education and justice system costs for both children and adults with ADHD reported higher costs and translated gross domestic product than did studies that captured only a single domain or age group.

CONCLUSIONS

Despite the wide variation in methodologies in studies reviewed, the literature suggests that ADHD imposes a substantial economic burden on society. There is a dire need for cost-of-illness research in low- and middle-income countries to better inform the treatment and management of ADHD in these countries. In addition, guidelines on the conduct and reporting of economic burden studies are needed as they may improve standardisation of cost-of-illness studies.

Residential pyrethroid insecticide use, urinary 3-phenoxybenzoic acid levels, and attention-deficit/hyperactivity disorder-like symptoms in preschool-age children: The Environment and Development of Children study

Previous animal studies have reported that pyrethroids can cause dopamine system abnormalities and attention-deficit/hyperactivity disorder (ADHD) phenotypes. However, epidemiological studies investigating the associations between pyrethroid exposure and ADHD are limited. We aimed to investigate the association between pyrethroid exposure and ADHD-like symptoms among preschool-age children. We used data from 385 children at 4 years of age participating in the Environment and Development of Children (EDC) study. We evaluated pyrethroid exposure through questionnaires and urinary 3-phenoxybenzoic acid (3-PBA) concentrations. We assessed ADHD-like symptoms using the Korean ADHD rating scale (K-ARS). We conducted negative binomial regressions to evaluate the associations between pyrethroid exposure and ADHD-like symptoms. Residential use of insecticide adhesive (β = 0.42, 95% CI: 0.11, 0.74) and insecticide spray (β = 0.33, 95% CI: 0.08, 0.59) was associated with an increase in log-transformed creatinine-adjusted urinary 3-PBA concentrations. Residential insecticide adhesive use was associated with a 51.6% increase in K-ARS scores (95% confidence interval [CI]: 6.3, 116.1) among boys, when compared with non-users. When compared with creatinine-adjusted 3-PBA levels <0.50 μg/g creatinine, creatinine-adjusted 3-PBA levels ≥3.80 μg/g creatinine were associated with a 58% increase in K-ARS scores (95% CI: 0.1, 150.5) among boys. We found associations of residential pyrethroid insecticide use and urinary 3-PBA concentrations with K-ARS scores among preschool-age boys. Since the present study explored cross-sectional associations in preschool-age children, the possibility of reverse causality cannot be dismissed. Further studies implementing a cohort study design are warranted.

Temporal trends and geographical variability of the prevalence and incidence of attention deficit/hyperactivity disorder diagnoses among children in Catalonia, Spain

Attention deficit/hyperactivity disorder (ADHD) is one of the most common behavioral disorders in childhood. According to a recent systematic review, the worldwide estimate of ADHD prevalence is 7.2% in children. This study aims to assess the prevalence of ADHD diagnoses in 2017 and the incidence of ADHD diagnoses in 2009–2017 in children living in Catalonia, Spain, as well as their temporal and geographical variability, and stratifying by sex and age. We used administrative data for all children aged 4 to 17 years who were insured in the public Catalan Health System in 2009–2017. We identified all ADHD cases diagnosed in 2009–2017 (ICD-9 code 314). We estimated the prevalence of ADHD diagnoses in 2017 and the overall annual incidence of ADHD diagnoses in 2009–2017. We used Poisson regression models to assess temporal trends in the incidence. We estimated a prevalence of ADHD diagnoses of 4.06% (95%CI 4.03, 4.10) in 2017, being 5.81% (95%CI 5.75, 5.87) for boys and 2.20% (95%CI 2.16, 2.24) for girls, the highest prevalence being in 13-to-17-year-olds (7.28% (95%CI 7.20, 7.36)). We did not observe a statistically significant increase of the incidence of ADHD diagnoses during the study period. Geographical differences were found across the healthcare areas in both prevalence and annual incidence and constant during the study period. In conclusion, the prevalence of ADHD diagnoses observed in this study was 4.06%, which was lower than the estimates reported in previous systematic reviews, but in line with the prevalence estimates from other recent European studies. The prevalence was higher in boys than girls, with a sex ratio consistent with previous studies. We did not observe an increase in the temporal trend of incidence of ADHD diagnoses in recent years, but we found geographical differences.

Attention-deficit/hyperactivity disorder (ADHD) symptoms and suicidality in children: The mediating role of depression, irritability and anxiety symptoms

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is associated with increased suicidality risk. Yet, potential mechanisms transmitting the effect of ADHD to suicidality remain unclear. We investigated whether depression, irritability and anxiety symptoms mediate between ADHD symptoms and suicidality.

METHODS

ADHD, depression, irritability and anxiety symptoms as well as suicidality (composited of suicidal ideation, attempts or self-harm) were measured in an outpatient clinic for ADHD (N = 1,516, 6-17 years old, 61.1% diagnosed with ADHD) using parent and teacher questionnaires. Multiple mediator models adjusted for age, sex and psychosocial adversities were constructed separately for parent- and teacher-report.

RESULTS

Parents reported higher rates of suicidality than did teachers (12.1% and 3.8%, p < .001). Suicidality was associated with parent (OR = 1.10, 95%CI: 1.07-1.14) and teacher (OR = 1.08, 95%CI: 1.03-1.15) reported ADHD symptoms. The association between ADHD symptoms and suicidality was mediated by both parent- and teacher-reported depression (39.1% and 45.3% of total effect, respectively) and irritability symptoms (36.8% and 38.4% of total effect, respectively). Anxiety symptoms mediated between ADHD and suicidality for parent- but not teacher-report (19.0% of total effect). No direct effect of ADHD symptoms was found once depression, irritability and anxiety were controlled.

LIMITATIONS

The cross-sectional design limits the ability to determine causal order between mediators and outcome.

CONCLUSIONS

Our results confirmed the association between ADHD symptoms and suicidality. However, this association was indirect and fully mediated by symptoms of depression, irritability and anxiety. Assessing these symptoms may enable an estimate of suicidality and help managing suicidal risk in ADHD.

Family structure, birth order, and aggressive behaviors among school-aged boys with attention deficit hyperactivity disorder (ADHD)

PURPOSE

To evaluate the associations between family structure, birth order, and aggressive behaviors among school-aged boys with attention deficit hyperactivity disorder (ADHD).

METHODS

We conducted a matched case-control study. Data were retrieved from medical records at a psychiatry center in northern Taiwan. School-aged boys with ADHD who first visited the outpatient department at the psychiatric center between 2000 and 2011 were identified. The Child Behavior Checklist was used for aggressive behavior assessment. Boys with ADHD with T scores higher than 70 on the aggressive subscale were classified as cases and others with T scores lower than 70 were classified as controls at a 1:4 ratio. After controlling for other familial, personal, and parental factors, a multivariate conditional logistic regression was performed to evaluate the effects of family structure and birth order on aggressive behaviors of boys with ADHD.

RESULTS

277 cases and 1108 controls were included in the final analysis. Compared with living in a traditional family with both parents, living in a non-traditional family in which one or both parents were absent increased the risk of aggressive behaviors by 1.47-fold, with the highest risk for those in single parent families. Being the firstborn increased risk by 1.45-fold and the risk was higher when the firstborn had siblings.

CONCLUSIONS

Living in non-traditional families in which one or both parents were absent, and being the firstborn increased risk of aggression in school-aged boys with ADHD. Identification of this high-risk population and development of adequate preventive strategies are warranted.