ADHD symptoms and body composition changes in childhood: a longitudinal study evaluating directionality of associations

Exploring Differences in Physical Health in Young Children With and Without ADHD

OBJECTIVE

To assess differences in child physical health outcomes and metrices associated with obesity in a sample of predominantly Hispanic/Latinx young children with and without attention-deficit/hyperactivity disorder (ADHD).

METHODS

Participants included 127 children diagnosed with ADHD and 96 typically developing (TD) children between 4 and 7 years of age. Objective measures of children's body composition, fitness, and physical activity were conducted. Parents of children completed food recalls to assess their child's dietary intake, diet quality was calculated based on the Healthy Eating Index-2015, and parents completed a survey about their family's health habits.

RESULTS

Logistic regression revealed that those with ADHD were more likely to be classified as having an overweight or obese (Ov/O) body mass index (BMI). Linear regression analyses indicated that children with ADHD performed worse on a fitness test and consumed more calories relative to TD children. Moderation analyses indicated that sex differences in steps were prominent in our TD sample, but not among those with ADHD.

CONCLUSIONS

Young children with ADHD are at greater risk for having an Ov/O BMI, being less fit, and eating a greater intake of calories compared to TD children.

Hyperactivity in preschool age is associated with higher fat-free mass and healthy lifestyle behaviours five years later: A longitudinal study of Swedish children

BACKGROUND

There is evidence for a link between hyperactivity and obesity, especially among older children. Both conditions seem to be multifactorial in origin and hypotheses of common underlying issues, such as emotional dysregulation, have been suggested. However, studies of the co-occurrence of the two conditions in younger age groups have been inconclusive.

OBJECTIVES

We aimed to study the longitudinal associations of psychological strengths and difficulties at 4 years of age with health behaviours, body composition, physical fitness, and cardiovascular disease (CVD) risk factors 5 years later.

METHODS

Parents of 226 4-year-old children filled out the Strengths and Difficulties Questionnaire (SDQ). At 9 years of age, we assessed health behaviours, physical fitness, body composition, and CVD risk factors. Associations were examined with linear regression models that were adjusted for sex, age of the child at 9, and maternal education.

RESULTS

In the adjusted models, hyperactivity at 4 was associated with higher fat-free mass (β = 0.18, p = 0.007) and lower levels of sedentary behaviour (β -0.14, p = 0.043) at 9 years. Furthermore, greater emotional problems at 4 were associated with lower intake of fruit and vegetables (β -0.14, p = 0.038) at 9 years. However, there were no statistically significant associations between psychological difficulties and fat-mass index.

CONCLUSIONS

Our novel data provide no evidence of an association between hyperactivity in preschool age and obesity or obesity-related behaviours in school age. Future studies examining how psychological factors relate to obesity development should consider a developmental perspective.

Anthropometric status of preschoolers and elementary school children with ADHD: preliminary results from the EPINED study

BACKGROUND

A current area of research interest is the association between ADHD and weight status. This paper aimed to describe the anthropometric status of school children with ADHD, considering age and clinical presentation (inattentive, hyperactive-impulsive, or combined), compared with control children.

METHODS

Participants came from the "Epidemiological Research Project on Neurodevelopmental Disorders" and consisted of 198 preschoolers (41 with ADHD) and 389 elementary school children (163 with ADHD). ADHD was diagnosed using DSM-5 criteria. Anthropometric measurements were taken at various anatomical points, and height, weight, and body composition were also measured.

RESULTS

In preschoolers, an association was found between hyperactive-impulsive ADHD and greater height and lower waist-to-height ratio. In elementary school children, regardless of the medication, combined ADHD was associated with smaller head, hip, arm, and thigh circumferences and lower weight, height, and BMI. A total of 19.7% of them were underweight. In contrast, children with inattentive and hyperactive/impulsive presentations presented the highest percentage of overweight/obesity (56%).

CONCLUSION

The anthropometric status of the school children with ADHD showed differences in terms of age and presentation. Preschoolers with hyperactive-impulsive ADHD are taller, and elementary school children with combined ADHD are shorter and smaller than their age-matched control peers.

IMPACT

The anthropometric status of the school children with ADHD showed differences in terms of age and presentation. Preschoolers with hyperactive-impulsive ADHD are taller than their control peers. Elementary school children with combined ADHD, regardless of the pharmacological treatment, are shorter and smaller than their control peers. Medication may anthropometrically affect the height of children with inattentive presentation. Anthropometric and dietary monitoring should be recommended to parents of children with ADHD, with and without medication.

The longitudinal influence of ADHD status and stimulant medication on body mass index and blood pressure among youth with obesity

BACKGROUND

Youth with attention-deficit hyperactivity disorder (ADHD) are more vulnerable to developing obesity. Stimulant medication use, an evidence-based treatment for ADHD, is associated with lower body mass index (BMI) and higher blood pressure among non-overweight youth.

OBJECTIVES

The purpose of this study was to examine the longitudinal influence of ADHD and stimulant medication use on BMI and blood pressure among a sample of 456 youth with overweight and obesity treated in a paediatric weight management clinic.

METHODS

Mixed linear modelling examined the main and interactive effects of time by ADHD status and stimulant medication use on BMI and blood pressure.

RESULTS

Youth without ADHD experienced a significantly faster decrease in BMI compared to youth with ADHD (p < 0.001). Youth with ADHD who were taking stimulant medication had a significantly faster decrease in BMI compared to youth with ADHD who were not taking stimulant medication (p = 0.009). There was no significant effect of ADHD status or stimulant medication use on diastolic or systolic blood pressure trajectories over time (ps >0.05).

CONCLUSIONS

Results from this study suggest that youth with ADHD who are not taking stimulant medication may not benefit from clinical weight management to the same extent as either youth without ADHD or youth with ADHD who are taking a stimulant medication.

Neurobehavioral phenotypes of delay discounting and cognitive control in child attention-deficit/hyperactivity disorder and obesity: Shared or distinct?

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) and obesity have been independently associated with deficient cognitive control (CC) and heightened preference for immediate reward.

OBJECTIVES

We aimed to identify specific shared and distinct neurobehavioral phenotypes of child obesity and ADHD by simultaneously measuring CC and preference for immediate reward in children with and without ADHD who varied in body weight.

METHODS

This case-control study included 323 8-12 year olds (ADHD n = 215, typically developing (TD) screened for ADHD symptoms [TD] controls n = 108) varying in body weight. Children completed a go/no-go task (assessing CC), as well as a classical money delay discounting (DD) task and novel experiential game time DD task (assessing preference for immediate over delayed rewards).

RESULTS

For game time DD, there was a body mass index z-score (BMIz)*ADHD interaction, such that TD children with overweight/obesity showed game time DD levels that were greater than those of TD children without overweight/obesity and similar to those of children with ADHD. Only children with ADHD showed poorer CC compared to TD children, with no effects of body weight.

CONCLUSIONS

Heightened game time DD with delays and rewards experienced in real-time may represent a neurobehavioral phenotype that is shared between ADHD and overweight/obesity in childhood, whereas deficient CC may be specific to children with ADHD.

Processed Food-Sweets Patterns and Related Behaviors with Attention Deficit Hyperactivity Disorder among Children: A Case-Control Study

BACKGROUND

Previous studies have focused on the associations between core symptoms and dietary intake in children with attention deficit hyperactivity disorder (ADHD). However, few studies have explored how dietary patterns and behaviors relate to the risk of ADHD. The aim of our study is to explore the associations between dietary patterns and behaviors and the risk of ADHD, which could provide evidence for follow-up and treatments for children with ADHD.

METHODS

We conducted a case-control study, including 102 children diagnosed with ADHD and 102 healthy children. The food frequency questionnaire (FFQ) and the children's eating behavior questionnaire (CEBQ) were used to investigate food consumption and eating behaviors. We applied exploratory factor analysis for constructing dietary patterns, and the factor scores were adopted for log-binomial regression to assess the associations between how dietary patterns and eating behaviors affect the risk of ADHD.

RESULTS

We extracted five dietary patterns with a cumulative contribution rate of 54.63%. Processed food-sweets scores revealed positive associations with an increased risk of ADHD (OR = 1.451, 95% CI: 1.041-2.085). Moreover, processed food-sweets tertile 3 was associated with an increased risk of ADHD (OR = 2.646, 95% CI: 1.213-5.933). In terms of eating behaviors, the group with a higher score relating to a desire to drink was also positively correlated with the risk of ADHD (OR = 2.075, 95% CI: 1.137-3.830).

CONCLUSIONS

In the treatment and follow-up of children with ADHD, dietary intake and eating behaviors should be considered.

Eating behavior-mediated association between attention deficit hyperactivity disorder and body fat mass

Background

Adverse eating behaviors and a high rate of obesity have been identified among children diagnosed with attention deficit hyperactivity disorder (ADHD). In this study, we investigate the relationships between eating behaviors and body fat mass among children with ADHD.

Methods

All participants were recruited from the Children's Health Care Department of the Children's Hospital of Nanjing Medical University from June 2019 to June 2020. ADHD was diagnosed according to the diagnostic criteria of the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) by psychiatrists. Core ADHD symptoms defined by the DSM-5 were inattention and hyperactivity/impulsivity. The anthropomorphic indices defined by the World Health Organization (WHO) were utilized in this study (body mass index [BMI], underweight, normal body mass, overweight, obesity, short stature). Body fat mass, fat mass percentage (FM%), skeletal muscle mass, skeletal muscle mass percentage (SMM%) were tested via body composition meter, and eating behaviors were assessed by parents using the Chinese version of the Children's Eating Behavior Questionnaire (CEBQ). The CEBQ was comprised of subscales related to food avoidant behaviors (satiety responsiveness, slowness in eating, fussiness, and emotional undereating) and food approach behaviors (food responsiveness, enjoyment of Food, desire to drink, and emotional overeating). The associations among ADHD, obesity and adverse eating behavior were tested through correlation analysis, and a mediating effect model was established to explore the effect of eating behaviors.

Results

A total of 548 participants aged 4-12 years were recruited. Among them, 396 were diagnosed with ADHD, with the remaining 152 enrolled in a control group. Compared with the control group, the ADHD group had higher incidences of overweight (22.5% vs. 14.5%) and obesity (13.4% vs. 8.6%) (p < 0.05). The ADHD group was more likely to display "slowness in eating" (11.01 ± 3.32 vs. 9.74 ± 2.95), "fussiness" (15.61 ± 3.54 vs. 15.03 ± 2.84), "food responsiveness" (11.96 ± 4.81 vs. 9.88 ± 3.71) and "desire to drink" (8.34 ± 3.46 vs. 6.58 ± 2.72) (p < 0.05). Moreover, The FM% of children with ADHD was positively correlated with inattention (β = 0.336, 95% CI: 0.001 to 0.673) and "food responsiveness" (β = 0.509, 95% CI: 0.352 to 0.665) in the multiple linear regression model. The mediation effect model showed that "food responsiveness" accounted for a significant portion (64.2%) of the mediating effect.

Conclusion

Children with ADHD had higher prevalence of overweight and obesity. As an important risk factor, food responsiveness may connect core symptoms of ADHD with obesity.

Child ADHD and autistic traits, eating behaviours and weight: A population-based study

BACKGROUND

Children with Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) have an increased obesity risk. Although these conditions commonly co-occur, shared factors relating to obesity risk are unknown.

OBJECTIVES

To examine the shared and unique associations of ADHD and autistic traits with eating behaviours and BMI.

METHODS

Children (N = 4134) from the population-based Generation R Study were categorized into subgroups based on parent-reported ADHD and autistic traits scores at 6 years: ADHD_High , ASD_High , ADHD+ASD_High and REF (reference group: ADHD+ASD_Low ). Multiple linear regressions examined the associations between subgroups and eating behaviours (at 10 years) and BMIz (at 14 years), relative to REF. Mediation analyses tested the indirect effect of subgroup and BMIz through eating behaviours.

RESULTS

ADHD + ASD_High children expressed both food approach (increased food responsiveness and emotional overeating) and avoidant eating behaviours (increased emotional undereating, satiety responsiveness/ slowness in eating and picky eating, and decreased enjoyment in food). ASD_High children were more food avoidant, while ADHD_High children had more food approach behaviours and greater BMIz. ADHD_High and BMIz were indirectly associated with food responsiveness and emotional overeating.

CONCLUSIONS

ADHD and autistic trait phenotypes show distinct associations with potential obesity risk factors, and further research is needed to improve targeted early intervention.

ADGRL3 genomic variation implicated in neurogenesis and ADHD links functional effects to the incretin polypeptide GIP

Attention deficit/hyperactivity disorder (ADHD) is the most common childhood neurodevelopmental disorder. Single nucleotide polymorphisms (SNPs) in the Adhesion G Protein-Coupled Receptor L3 (ADGRL3) gene are associated with increased susceptibility to developing ADHD worldwide. However, the effect of ADGRL3 non-synonymous SNPs (nsSNPs) on the ADGRL3 protein function is vastly unknown. Using several bioinformatics tools to evaluate the impact of mutations, we found that nsSNPs rs35106420, rs61747658, and rs734644, previously reported to be associated and in linkage with ADHD in disparate populations from the world over, are predicted as pathogenic variants. Docking analysis of rs35106420, harbored in the ADGLR3-hormone receptor domain (HRM, a common extracellular domain of the secretin-like GPCRs family), showed that HRM interacts with the Glucose-dependent insulinotropic polypeptide (GIP), part of the incretin hormones family. GIP has been linked to the pathogenesis of diabetes mellitus, and our analyses suggest a potential link to ADHD. Overall, the comprehensive application of bioinformatics tools showed that functional mutations in the ADGLR3 gene disrupt the standard and wild ADGRL3 structure, most likely affecting its metabolic regulation. Further in vitro experiments are granted to evaluate these in silico predictions of the ADGRL3-GIP interaction and dissect the complexity underlying the development of ADHD.

Attention-Deficit/Hyperactivity Disorder and Obesity: A National Study of 1.1 Million Israeli Adolescents

PURPOSE

The incidences of obesity and attention-deficit/hyperactivity disorder (ADHD) have increased in parallel over recent decades. We assessed the association between obesity and ADHD in a national sample of adolescents.

METHOD

In a nationwide population-based study of 1 118 315 adolescents (57% males; mean age 17 years), risks of obesity were compared between individuals with severe and mild ADHD and those without ADHD. Diagnoses of ADHD were confirmed by specialists in either neurology or psychiatry. Adolescents requiring regular and continuous treatment with stimulants with no improvement of symptoms under treatment were classified as having severe ADHD; data were available from 2004 to 2019. During 2015 to 2019, the diagnosis of ADHD was defined, and 65 118 (16.76%) of 388 543 adolescents with mild symptoms who required medications only for learning or who used stimulants irregularly were defined as having mild ADHD.

RESULTS

The prevalence of severe and mild ADHD was 0.3% and 20.1%, respectively. Obesity was more prevalent among adolescents with severe ADHD than among those without ADHD (13.5% vs 7.5%). In the mild ADHD group 12.6% of males and 8.4% of females were diagnosed with obesity compared to 9.7% and 6.4%, respectively, in the non-ADHD group. The adjusted odds of severe ADHD for males and females with obesity were 1.77 (1.56-2.02) and 2.09 (1.63-2.66) times the odds for males and females with low-normal body mass index, respectively, and 1.42 (1.37-1.48) and 1.42 (1.34-1.50) for males and females with mild ADHD, respectively. The elevated risk persisted in several sensitivity analyses.

CONCLUSIONS

Both adolescents with severe and mild ADHD are at increased risk for obesity.

ADHD in childhood predicts BMI and body composition measurements over time in a population-based birth cohort

BACKGROUND/OBJECTIVES

Obesity has been reported as an attention-deficit hyperactivity disorder (ADHD) comorbidity. So far, few studies have aimed to explore the potential causal relationship between ADHD and obesity, as well as used other measures of body composition like fat-free mass (FFM) and fat mass (FM) as measures of obesity. This study aimed to test the association between ADHD and body composition (body mass index [BMI] and others) and to evaluate the potential causal relationship with obesity.

SUBJECTS/METHODS

Data from the 1993 Pelotas (Brazil) birth cohort at age 11-, 15-, 18-, and 22-year follow-up was used. We performed a cross-lagged panel model (CLPM) analysis between ADHD symptoms and BMI to explore the causal relationship between both traits. Finally, we tested whether ADHD, inattention, and hyperactivity symptom scales were associated with BMI, FM, and FFM at 22 years.

RESULTS

In the CLPM, higher ADHD scores at age 11 predicted higher BMI at age 15 (β = 0.055, 95% CI [0.037; 0.073]). ADHD symptoms at age 11 was also associated with a decrease in the FFM (β = -0.16, 95% CI [-0.28; -0.05]), and an increase in the BMI (β = 0.17, 95% CI [0.10; 0.23]) and FM (β = 0.17, 95% CI [0.06; 0.29]) at 22 years. At 22 years of age, ADHD was associated with FFM and FM. Moreover, an increase in BMI was observed with an increase in several symptoms of ADHD in general (β = 0.06, 95% CI [0.004; 0.12]), and hyperactivity symptoms (β = 0.15, 95% CI [0.05; 0.25]).

CONCLUSION

ADHD at 11 years predicted a higher BMI at 15 years, and body fat composition in adulthood, suggesting higher scores on ADHD symptoms in early life may be a critical point for body composition in early adulthood. The hyperactivity symptoms may play an important role in the BMI increase.

Obesity and Attention-Deficit Hyperactivity Disorder

An association between ADHD and obesity has been established throughout the past 20 years via animal model experiments and both correlational and longitudinal studies in humans. However, much remains to be determined regarding causality, developmental course, and effective treatments targeting both conditions. This chapter provides an overview and update on the current state of the science on the relationship between obesity and ADHD; expands the scope of the connection between obesity and ADHD to include behavioral components important to weight regulation - i.e., physical activity, eating behaviors, and sleep; and presents applications of these findings to treatment approaches and future directions.

The longitudinal association of eating behaviour and ADHD symptoms in school age children: a follow-up study in the RHEA cohort

Previous evidence suggests a link between attention deficit hyperactivity disorder (ADHD) symptoms and disordered eating behaviours; however, the direction of the causal association remains unclear. Building on our previous research, we aimed to examine the longitudinal association between eating behaviours at 4 years, ADHD symptoms at 6 years of age, and the role of body mass index (BMI). We included children from the RHEA mother-child cohort in Greece, followed up at 4 and 6 years (n = 926). Parents completed the Children's Eating Behaviour Questionnaire (CEBQ) to assess children's eating behaviour at 4 years and the ADHD Test (ADHDT) and Child Behaviour Checklist for ages 6-18 (CBCL/6-18) to evaluate ADHD symptoms at 4 and 6 years, respectively, as well as measures of BMI. Longitudinal structural equation modeling (SEM) was carried out to evaluate the associations of all variables between 4 and 6 years. Food responsiveness at 4 years was positively associated with hyperactivity at age 6, whereas emotional overeating was negatively associated with hyperactivity. There was no evidence of an association between eating behaviours of preschoolers and BMI at 6 years, or BMI at 4 years and later ADHD symptoms and vice versa. Findings suggest that food responsiveness is an early marker of ADHD symptoms at 6 years of age. In contrast to our hypothesis there was no significant association between ADHD at age 4 and BMI at age 6.

The link between attention deficit hyperactivity disorder (ADHD) symptoms and obesity-related traits: genetic and prenatal explanations

Attention-deficit/hyperactivity disorder (ADHD) often co-occurs with obesity, however, the potential causality between the traits remains unclear. We examined both genetic and prenatal evidence for causality using Mendelian Randomisation (MR) and polygenic risk scores (PRS). We conducted bi-directional MR on ADHD liability and six obesity-related traits using summary statistics from the largest available meta-analyses of genome-wide association studies. We also examined the shared genetic aetiology between ADHD symptoms (inattention and hyperactivity) and body mass index (BMI) by PRS association analysis using longitudinal data from Northern Finland Birth Cohort 1986 (NFBC1986, n = 2984). Lastly, we examined the impact of the prenatal environment by association analysis of maternal pre-pregnancy BMI and offspring ADHD symptoms, adjusted for PRS of both traits, in NFBC1986 dataset. Through MR analyses, we found evidence for bidirectional causality between ADHD liability and obesity-related traits. PRS association analyses showed evidence for genetic overlap between ADHD symptoms and BMI. We found no evidence for a difference between inattention and hyperactivity symptoms, suggesting that neither symptom subtype is driving the association. We found evidence for association between maternal pre-pregnancy BMI and offspring ADHD symptoms after adjusting for both BMI and ADHD PRS (association p-value = 0.027 for inattention, p = 0.008 for hyperactivity). These results are consistent with the hypothesis that the co-occurrence between ADHD and obesity has both genetic and prenatal environmental origins.

Impact of CNS Stimulants for Attention-Deficit/Hyperactivity Disorder on Growth: Epidemiology and Approaches to Management in Children and Adolescents

Central nervous system stimulants are established treatments for pediatric attention-deficit/hyperactivity disorder with robust efficacy data. Reductions in appetite, weight, and growth velocity are some of the most common concerns regarding the long-term use of central nervous system stimulants in developing children. They are associated with suppression of weight and body mass index in childhood. However, both weight and body mass index often progressively increase over adolescence at rates faster than those seen in non-attention-deficit/hyperactivity disorder youth to the degree that attention-deficit/hyperactivity disorder is associated with elevated body mass index by the end of adolescence regardless of medication use. The capacity of central nervous system stimulants to slow growth was identified 50 years ago. Recent work has established that the growth deficits accumulate during the first 2 years of use and may persist provided medication is used. Early initiation coupled with persistent use through adolescence is most likely to be associated with clinical impactful growth suppression. There has been limited formal investigation of treatments for stimulant-associated reductions in weight and height. The most robust evidence exists for drug holidays improving weight gain. Observational studies suggest that limiting lifetime exposure or discontinuing medication is associated with greater adult height. Additional research is needed to identify the causal mechanisms driving the observed slowing in growth as well as the identification of predictors of clinically impactful growth suppression.

Longitudinal Associations Between Symptoms of ADHD and BMI From Late Childhood to Early Adulthood

BACKGROUND AND OBJECTIVES

Attention-deficit/hyperactivity disorder (ADHD) and obesity are 2 frequent conditions that co-occur, which has implications for the management of both conditions. We hypothesized that ADHD symptoms predict BMI and vice versa from late childhood (10-12 years) up to early adulthood (20-22 years).

METHODS

Participants were adolescents in the Netherlands (n = 2773, 52.5% male, mean age = 11 years at baseline, 5 waves up to mean age 22) from the Tracking Adolescents' Individual Lives Survey cohort. We examined bidirectional relationship between ADHD symptoms (hyperactivity/impulsivity and inattention) and BMI using the random intercept cross-lagged panel model. Time-varying covariates were pubertal status, stimulant use, depressive symptoms, and family functioning, and socioeconomic status was a time-invariant covariate.

RESULTS

We found a time-invariant association of BMI with hyperactivity and impulsivity, but not with inattention, which was slightly stronger in female adolescents (female: r = 0.102; male: r = 0.086, P < .05). No longitudinal direct effects were found between ADHD symptoms and BMI during this period.

CONCLUSIONS

Over the course of adolescence, the link between ADHD and BMI is stable and is predominantly with hyperactive and impulsive symptoms rather than inattention. There was no direct effect of ADHD symptoms on BMI increase nor of BMI on enhanced ADHD symptoms during this developmental period. The findings point to a shared genetic or familial background and/or potential causal effects established already earlier in childhood, thus suggesting that intervention and prevention programs targeting overweight and obesity in children with ADHD should be implemented in early childhood.

Are there causal relationships between attention-deficit/hyperactivity disorder and body mass index? Evidence from multiple genetically informed designs

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) and body mass index (BMI) are associated. However, it remains unclear whether this association reflects causal relationships in either direction or confounding. Here, we implemented genetically informed methods to examine bidirectional causality and potential confounding.

METHODS

Three genetically informed methods were employed: (i) cross-lagged twin-differences analyses to assess bidirectional effects of ADHD symptoms and BMI at ages 8, 12, 14 and 16 years in 2386 pairs of monozygotic twins from the Twins Early Development Study (TEDS); (ii) within- and between-family ADHD and BMI polygenic score (PS) analyses in 3320 pairs of dizygotic TEDS twins; and (iii) two-sample bidirectional Mendelian randomization (MR) using summary statistics from genome-wide association studies (GWAS) on ADHD (N = 55,374) and BMI (N = 806,834).

RESULTS

Mixed results were obtained across the three methods. Twin-difference analyses provided little support for cross-lagged associations between ADHD symptoms and BMI over time. PS analyses were consistent with bidirectional relationships between ADHD and BMI, with plausible time-varying effects from childhood to adolescence. MR findings also suggested bidirectional causal effects between ADHD and BMI. Multivariable MR indicated the presence of substantial confounding in bidirectional relationships.

CONCLUSIONS

The three methods converged to highlight multiple sources of confounding in the association between ADHD and BMI. PS and MR analyses suggested plausible causal relationships in both directions. Possible explanations for mixed causal findings across methods are discussed.

Obesity and ADHD: Exploring the role of body composition, BMI polygenic risk score, and reward system genes

The association between obesity and attention-deficit hyperactivity disorder (ADHD) has been extensively reported in the literature. However, the potential mechanisms underlying this association are not completely understood. This study aimed to evaluate the association between body composition and ADHD and explore the possible genetic mechanisms involved. We used data from the 1982 Pelotas (Brazil) Birth Cohort at age 30-year follow-up (N = 3630). We first used logistic regression analysis to test whether body mass index (BMI), fat mass (FM), and fat-free mass (FFM) were associated with ADHD. We further tested the association between BMI polygenic risk score (BMI-PRS) and ADHD and the role of the genes upregulated in the reward system using a gene-set association approach. BMI (odds ratio [OR] = 1.05; 95% confidence interval [CI], 1.00-1.09; p = 0.038) and FM (OR = 1.04; 95% CI, 1.00-1.07; p = 0.043) were associated with ADHD. The BMI-PRS was associated with ADHD (using p-value threshold (P_T) = 0.4; OR = 1.65; 95% CI, 1.02-2.65) at a nominal level. In gene-set analysis, the reward system genes were associated with BMI in subjects with a high BMI-PRS score, considering P_T = 0.4 (p = 0.014). The results suggest that BMI genetic components, especially those genes related to the reward system, may be involved in this association.

[Overweight/Obesity of Children and Adolescents and its Association with Internalising and Externalising Disorders]

Overweight/Obesity of Children and Adolescents and its Association with Internalising and Externalising Disorders Research in child and adolescent psychiatry increasingly deals with the association between mental disorder and weight. This paper provides an overview of national and international studies on the relationship between body composition and mental illness in children and adolescents, with a focus on the representation of individual internalizing and externalizing disturbance patterns. The majority of studies in this area are based on the so-called one-compartment model of body composition in terms of the Body Mass Index (BMI) or on the classification as "overweight" or "obese". Associations between mental disorders and body composition were described in two directions: On one hand, both externalising and internalising symptoms are associated with obesity, and on the other hand there are also more psychopathological symptoms among overweight children and adolescents. Longitudinal studies suggest effects in both directions. While externalising symptoms and weight are thought to be related from infancy on, this connection seems to be evident for internalising disorders not earlier than for early school age. It is also known from the literature that psychopharmacological medication affects weight and body growth - especially with psychostimulants, but also with neuroleptics and antidepressants. We found only a few studies describing the relationship between body composition and psyche in more complex models with two or more compartments.

Prenatal and perinatal factors associated with ADHD risk in schoolchildren: EPINED epidemiological study

The aim of this study is to assess the relationship between pre- and perinatal factors and ADHD in a sample of scholars exploring differences between ADHD presentations and spectrum of severity. A total of 6720 scholars (aged 3-4 and 10-11) participated in a double-phase epidemiologic cross-sectional study (Epidemiological Study of Neurodevelopmental Disorders, EPINED), and a sample of 646 scholars (ADHD risk, ASD risk and controls without risk) were individually assessed in the second phase of the study. The ADHD diagnosis, based on DSM-5 criteria, was performed with the Kiddie-Schedule for Affective Disorders & Schizophrenia, Present & Lifetime Version. Associations for the different ADHD presentations between prenatal, perinatal and postnatal factors and ADHD (n = 168), subclinical ADHD (n = 88) and non-ADHD (n = 310) were analysed. Logistic regression models showed that gestational diabetes (p = 0.012), instrumental delivery (p = 0.011), family history of psychopathology (p = 0.033) and maternal ADHD phenotype (p = 0.023) were associated with ADHD. These factors were related to the hyperactive-impulsive and combined presentations, but they were not related to the inattentive presentation. Maternal weight gain was associated with subclinical ADHD. In conclusion, metabolic disorder in the pregnancy, difficulties in childbirth and specific family phenotype were related to ADHD, specifically with hyperactive-impulsive presentation, but not in subclinical ADHD.

ADHD and Risk of Childhood Adiposity: a Review of Recent Research

PURPOSE OF REVIEW

Attention deficit/hyperactivity disorder (ADHD) is considered as a risk factor for childhood adiposity and obesity. Studies on ADHD have provided limited data concerning the connections between eating habits, body mass index, and obesity. The purpose of this review was to examine the current literature regarding recent cohort and cross-sectional studies to determine the links between ADHD and childhood adiposity.

RECENT FINDINGS

Studies in this review were classified into dietary features, nutritional status, neuroimaging findings, genetic overlapping, behavioral, cognitive, and neurocognitive aspects that play a role in mediating and moderating the relationship between ADHD and obesity. While ADHD, childhood adiposity, and overweight/obesity co-occur in children and adolescents, this relationship is largely explained by a variety of multidirectional factors.

No Evidence for Passive Gene-Environment Correlation or the Influence of Genetic Risk for Psychiatric Disorders on Adult Body Composition via the Adoption Design

The relationship between genetic and environmental risk is complex and for many traits, estimates of genetic effects may be inflated by passive gene-environment correlation. This arises because biological offspring inherit both their genotypes and rearing environment from their parents. We tested for passive gene-environment correlation in adult body composition traits using the 'natural experiment' of childhood adoption, which removes passive gene-environment correlation within families. Specifically, we compared 6165 adoptees with propensity score matched non-adoptees in the UK Biobank. We also tested whether passive gene-environment correlation inflates the association between psychiatric genetic risk and body composition. We found no evidence for inflation of heritability or polygenic scores in non-adoptees compared to adoptees for a range of body composition traits. Furthermore, polygenic risk scores for anorexia nervosa, attention-deficit/hyperactivity disorder and schizophrenia did not differ in their influence on body composition traits in adoptees and non-adoptees. These findings suggest that passive gene-environment correlation does not inflate genetic effects for body composition, or the influence of psychiatric disorder genetic risk on body composition. Our design does not look at passive gene-environment correlation in childhood, and does not test for 'pure' environmental effects or the effects of active and evocative gene-environment correlations, where child genetics directly influences home environment. However, these findings suggest that genetic influences identified for body composition in this adult sample are direct, and not confounded by the family environment provided by biological relatives.

Low cardiorespiratory fitness and obesity for ADHD in childhood and adolescence: A 6-year cohort study

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent disorder in childhood and identifying risk factors associated with developing ADHD during childhood and adolescence is relevant from a clinical and epidemiological point of view. This work examines (a) whether overweight/obesity and low cardiorespiratory fitness (CRF) are associated with increased ADHD symptoms in childhood (cross-sectional analysis), and (b) whether overweight/obesity and low CRF levels during childhood predict increased ADHD symptoms in adolescence (longitudinal analysis). Data were examined from a longitudinal study of Estonian inhabitants who took part in the European Youth Heart Study (EYHS) in 1998 and 1999 (baseline age 9 years), who were re-evaluated 6 years later as part of the longitudinal Estonian Children Personality Behaviour and Health Study (ECPBHS). CRF was determined via an incremental maximal cycle-ergometer test, overweight/obesity was based on body mass index (BMI), and the 7-point af Klinteberg Hyperactivity Scale was used to assess ADHD symptoms at both time points. In the cross-sectional analysis, children with overweight/obesity were at greater risk of ADHD symptoms compared to underweight/normal weight children, as were those unfit compared to fit children (OR = 1.92 and 95%CI = 1.02-3.55, and OR = 1.84 and 95%CI = 1.13-2.98, respectively). The cross-sectional association between BMI and ADHD symptoms was mediated by CRF (z = 2.116, 42.9%; P = .034). The longitudinal analysis showed being unfit in childhood was associated with a greater risk of increased ADHD symptoms 6 years later in adolescence (OR = 2.26 and 95%CI = 1.14-4.47), even after adjusting for baseline ADHD symptoms and BMI. Our result suggests that being unfit is an additional risk factor for increased ADHD symptoms during childhood and adolescence. The association between BMI and ADHD symptoms was mediated by CRF in the cross-sectional analysis, and no association was seen between overweight/obesity and increased ADHD symptoms.

Attention Deficit Hyperactivity Disorder: Association With Obesity and Eating Disorders

Attention deficit hyperactivity disorder (ADHD) is one of the most common treatable psychiatric illnesses that affect all age groups from children to adults. Most commonly it is diagnosed in childhood or during teenage years. It can affect the mental and physical health of an individual and disrupt normal academic, career, and social functioning. The quality of life of the individual is affected; thus if diagnosed and treated, the results are good. Obesity and eating disorders are one of the comorbidities associated with ADHD and can lead to various other health problems. This study was done to find out the association between ADHD, obesity, eating disorders, and the effect of medication. We collected data from various studies through multiple electronic databases such as PubMed and Google Scholar. We found 8610 relevant articles and finally narrowed it down to 30 using various criteria. An association was found between ADHD, obesity, and eating disorders, although the mechanism linking ADHD, obesity, and eating disorders still remains unclear according to most studies. Some studies say ADHD medication helps in losing gained weight; some say they do not affect the weight.

The Co-occurrence of Pediatric Obesity and ADHD: an Understanding of Shared Pathophysiology and Implications for Collaborative Management

PURPOSE OF REVIEW

To describe what is known about the association between obesity and attention-deficit hyperactivity disorder (ADHD) in children along with the co-occurring conditions of sleep dysfunction, loss of control/binge eating disorder (LOC-ED/BED), and anxiety.

RECENT FINDINGS

Obesity and ADHD share common brain pathways (hypothalamic, executive, and reward centers) with pathophysiology in these areas manifesting in partial or complete expression of these diseases. Sleep dysfunction, LOC-ED/BED, and anxiety share similar pathways and are associated with this disease dyad. The association of obesity and ADHD with sleep dysfunction, LOC-ED/BED, and anxiety is discussed. An algorithm outlining decision pathways for patients with obesity and with and without ADHD is presented. Future research exploring the complex pathophysiology of both obesity and ADHD as well as co-occurring conditions is needed to develop clinical guidelines and ultimately assist in providing the best evidence-based care.

Negative Affectivity and Emotion Dysregulation as Mediators between ADHD and Disordered Eating: A Systematic Review

Attention-Deficit/Hyperactivity Disorder (ADHD) is associated with disordered eating, especially addictive-like eating behavior (i.e., binge eating, food addiction, loss of control overeating). The exact mechanisms underlying this association are unclear. ADHD and addictive-like eating behavior are both associated with negative affectivity and emotion dysregulation, which we hypothesized are mediators of this relationship. The purpose of this systematic review was to review the evidence related to this hypothesis from studies assessing the relationship between childhood or adulthood ADHD symptomatology, negative affectivity, emotion dysregulation and addictive-like eating behavior. The systematic review followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) recommendations. The literature search was conducted in PubMed and PsycINFO (publication date: January 2015 to August 2020; date of search: 2 September 2020). Out of 403 potentially relevant articles, 41 were retained; 38 publications reported that ADHD and disordered eating or addictive-like eating behavior were significantly associated, including 8 articles that suggested a mediator role of negative affectivity or emotion dysregulation. Sixteen publications reported that the association between ADHD symptomatology and disordered eating or addictive-like eating behavior differed according to gender, eating behavior and ADHD symptoms (hyperactivity, impulsivity and inattention). We discuss the practical implications of these findings and directions future research.

The stress-Wnt-signaling axis: a hypothesis for attention-deficit hyperactivity disorder and therapy approaches

Attention-deficit hyperactivity disorder (ADHD) is one of the most common psychiatric neurodevelopmental disorders in children and adolescents. Although ADHD has been studied for nearly a century, the cause and pathophysiology of ADHD is yet largely unknown. However, findings from previous studies have resulted in the formation of a new hypothesis: Apart from the well-known multifactorial etiology of ADHD, recent evidence suggests that the interaction between genetic and environmental factors and especially Wnt- and mTOR-signaling pathways might have an important role in the pathophysiology of ADHD. The Wnt-signaling pathway is known to orchestrate cellular proliferation, polarity, and differentiation, and the mTOR pathway is involved in several significant processes of neurodevelopment and synaptic plasticity. As a result, dysregulations of these pathways in a time-dependent manner could lead to neurodevelopmental delays, resulting in ADHD phenotype. This review presents further evidence supporting our hypothesis by combining results from studies on ADHD and Wnt- or mTOR-signaling and the influence of genetics, methylphenidate treatment, Omega-3 supplementation, and stress.

The influence of preschoolers' emotional and behavioural problems on obesity treatment outcomes: Secondary findings from a randomized controlled trial

BACKGROUND

Few studies have explored the influence of preschoolers' behavioural problems on obesity treatment.

OBJECTIVES

To assess emotional and behavioural problems before and after an obesity intervention and examine relationships between changes in child behaviour and changes in weight status.

METHOD

The study included 77 children (4-6 years old, 53% girls, mean body mass index [BMI] z-score of 3.0 [SD 0.6]) who participated in the More and Less Study, a randomized controlled trial. Families were randomized to a parenting program or to standard treatment. The children's heights and weights (BMI z-score, primary outcome) were measured at baseline and 12 months post baseline. Parents rated their children's behaviours (secondary outcome) on the Child Behavior Checklist (CBCL) for ages 1.5 to 5 years, a questionnaire that measures psychosocial health and functioning, encompassing emotional and behavioural problems. Changes in child behaviour during treatment were examined through paired samples t tests; the influence of child behaviour on treatment effects was examined through linear regressions.

RESULTS

Child emotional and behavioural problems significantly improved after obesity treatment. Lower scores were found for Emotional Reactivity, Sleep Problems, Affective Problems, Aggressive Behaviour, Externalizing Behaviours, Oppositional Defiant Problems, and Total Problems. Child behaviour significantly affected obesity treatment results: Attention Problems and attention deficit hyperactivity disorder (ADHD) at baseline contributed to increasing BMI z-scores, whereas Oppositional Defiant Problems, Externalizing Behaviours, and a higher number of behavioural problems predicted decreasing BMI z-scores.

CONCLUSIONS

Child behaviours at baseline influenced treatment results. Child emotional and behavioural problems improved post treatment. The results suggest that obesity treatment may help in reducing emotional distress among preschoolers.

Executive functioning and neurodevelopmental disorders in early childhood: a prospective population-based study

BACKGROUND

Executive functioning deficits are common in children with neurodevelopmental disorders. However, prior research mainly focused on clinical populations employing cross-sectional designs, impeding conclusions on temporal neurodevelopmental pathways. Here, we examined the prospective association of executive functioning with subsequent autism spectrum disorder (ASD) traits and attention-deficit/hyperactivity disorder (ADHD) traits.

METHODS

This study included young children from the Generation R Study, a general population birth cohort. The Brief Rating Inventory of Executive Function-Preschool Version was used to assess parent-reported behavioral executive functioning when the children were 4 years old. ASD traits were assessed at age 6 (n = 3938) using the parent-reported Social Responsiveness Scale. The Teacher Report Form was used to assess ADHD traits at age 7 (n = 2749). Children with high scores were screened to determine possible clinical ASD or ADHD diagnoses. We were able to confirm an ASD diagnosis for n = 56 children by retrieving their medical records and established an ADHD diagnosis for n = 194 children using the Diagnostic Interview Schedule for Children-Young Child version (DISC-YC). Data were analyzed using hierarchical linear and logistic regressions.

RESULTS

Impaired executive functioning was associated with more ASD and ADHD traits across informants (for ASD traits and diagnoses: β = 0.33, 95% CI [0.30-0.37]; OR = 2.69, 95% CI [1.92-3.77], respectively; for ADHD traits and diagnoses: β = 0.12, 95% CI [0.07-0.16]; OR = 2.32, 95% CI [1.89-2.85], respectively). Deficits in all subdomains were associated with higher levels of ASD traits, whereas only impaired inhibition, working memory, and planning/organization were associated with more ADHD traits.

CONCLUSIONS

The findings of the current study suggest a graded association of executive functioning difficulties along the continuum of ASD and ADHD and that problems in executive functioning may be a precursor of ASD and ADHD traits from an early age onwards.

The Association between ADHD and Obesity: Intriguing, Progressively More Investigated, but Still Puzzling

This narrative review is aimed at presenting the most recent evidence on the association between attention-deficit/hyperactivity disorder (ADHD) and obesity. The review is informed by previous relevant systematic reviews and a search in Pubmed and PsycINFO up to 1 August 2019. Although the association between ADHD and obesity would seem, at first, paradoxical, in the past two decades there has been an increasing number of studies on this topic. The present review shows that there is meta-analytic evidence supporting a significant association between these two conditions, at least in adults. Growing evidence is also being published on the genetic and environmental factors underlying the association. However, the cause–effects paths, as well as the exact mechanisms explaining the association, remain unclear. Additionally, empirical evidence guiding the management/treatment of patients with the two conditions is still limited. Therefore, after almost 20 years from the first report of a link between ADHD and obesity, this association continues to be puzzling.

Omega-3 Long-Chain Polyunsaturated Fatty Acids Intake in Children with Attention Deficit and Hyperactivity Disorder

Omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) play a central role in neuronal growth and in the development of the human brain, and a deficiency of these substances has been reported in children with attention deficit hyperactive disorder (ADHD). In this regard, supplementation with omega-3 polyunsaturated fatty acids is used as adjuvant therapy in ADHD. Seafood, particularly fish, and some types of nuts are the main dietary sources of such fatty acids in the Spanish diet. In order to assess the effect of the intake of common foods containing high amounts of omega-3 polyunsaturated fatty acids, a food frequency questionnaire was administered to parents of children with ADHD (N = 48) and to parents of normally developing children (control group) (N = 87), and the intake of dietary omega-3 LC-PUFA, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), was estimated. Children with ADHD consumed fatty fish, lean fish, mollusks, crustaceans, and chicken eggs significantly less often (p < 0.05) than children in the control group. The estimated daily omega-3 LC-PUFA intake (EPA + DHA) was significantly below that recommended by the public health agencies in both groups, and was significantly lower in children with ADHD (p < 0.05, Cohen’s d = 0.45) compared to normally developing children. Dietary intervention to increase the consumption of fish and seafood is strongly advised and it is especially warranted in children with ADHD, since it could contribute to improve the symptoms of ADHD.