Meta-Analysis of Sex Differences in ADHD Symptoms and Associated Cognitive Deficits

Sex differences in attention-deficit hyperactivity disorder diagnosis and clinical care: a national study of population healthcare records in Wales

BACKGROUND

Population-based studies have observed sex biases in the diagnosis and treatment of attention-deficit hyperactivity disorder (ADHD). Females are less likely to be diagnosed or prescribed ADHD medication. This study uses national healthcare records, to investigate sex differences in diagnosis and clinical care in young people with ADHD, particularly regarding recognition and treatment of other mental health conditions.

METHODS

The cohort included individuals diagnosed with ADHD, born between 1989 and 2013 and living in Wales between 2000 and 2019. Routine primary and secondary healthcare record data were used to derive diagnoses of ADHD and other neurodevelopmental and mental health conditions, as well as ADHD and antidepressant medications. Demographic variables included ethnicity, socioeconomic deprivation and contact with social services.

RESULTS

There were 16,458 individuals diagnosed with ADHD (20.3% females, ages 3-30 years), with a male-to-female ratio of 3.9:1. Higher ratios (4.8:1) were seen in individuals diagnosed younger (<12 years), with the lowest ratio (1.9:1) in those diagnosed as adults (>18). Males were younger at first recorded ADHD diagnosis (mean = 10.9 vs. 12.6 years), more likely to be prescribed ADHD medication and younger at diagnosis of co-occurring neurodevelopmental conditions. In contrast, females were more likely to receive a diagnosis of anxiety, depression or another mental health condition and to be prescribed antidepressant medications, prior to ADHD diagnosis. These sex differences were largely stable across demographic groups.

CONCLUSIONS

This study adds to the evidence base that females with ADHD are experiencing later recognition and treatment of ADHD. The results indicate that this may be partly because of diagnostic overshadowing from other mental health conditions, such as anxiety and depression, or initial misdiagnosis. Further research and dissemination of findings to the public are needed to improve awareness, timely diagnosis and treatment of ADHD in females.

No evidence for a causal contribution of bioavailable testosterone to ADHD in sex-combined and sex-specific two-sample Mendelian randomization studies

The higher prevalence of attention-deficit/hyperactivity disorder (ADHD) in males raises the question of whether testosterone is implicated in ADHD risk. However, cross-sectional studies did not identify an association between ADHD and testosterone levels. Mendelian randomization (MR) studies can overcome limitations inherent to association studies, especially of reverse causation and residual confounding. In the current study, sex-combined and sex-specific two-sample MR analyses were conducted to address whether testosterone has a causal influence on ADHD risk. Sex-combined as well as sex-specific target-genetic variants for bioavailable testosterone were derived from a large genome-wide association study (GWAS) on up to 382,988 adult white European UK Biobank study participants. In our sex-specific analyses for ADHD, including data from 14,154 males and 4,945 females with ADHD (17,948 and 16,246 controls respectively), no association between bioavailable testosterone and ADHD risk was found, neither in males (inverse-variance weighted (IVW): beta = 0.09, 95%-CI [-0.10, 0.27]) nor in females (IVW: beta=-0.01, 95%-CI [-0.20, 0.19]). However, in the sex-combined analysis, including 38,691 cases and 186,843 controls, genetically predicted bioavailable testosterone was associated with ADHD risk (IVW: beta = 0.24, 95%-CI [0.09, 0.39]). The inclusion of birth weight and/or SHBG as additional variables in multivariable MR analyses did not alter this result. However, when correcting for potential BMI-driven pleiotropy by a multivariable MR study, all effect estimates for testosterone showed non-significant results. Taken together, no robust evidence for a causal effect of bioavailable testosterone on the risk for ADHD was found.

Absent or Hidden? Hyperactivity in Females With ADHD

OBJECTIVE

This study aimed to objectively assess signs of hyperactivity in adults suspected of having ADHD, addressing potential sex bias in diagnosis.

METHODS

About 13,179 (49% female) adults with an average age of 33 years with ADHD and 1,910 (41% female) adults with an average age of 36 years without ADHD were included. Motor activity was measured using the Quantified Behavioral Test, analyzing "provoked," and "basal" activity. Sex by group differences were analyzed using analysis of variance.

RESULTS

Results showed significant ADHD effects on the basal and provoked activity measures, while sex effects were only notable for provoked activity. Males, irrespective of diagnosis, exhibited higher provoked activity than females, while both sexes with ADHD displayed approximately twice the basal activity and about three times the provoked activity compared to their respective sex controls.

CONCLUSION

These findings suggest that females with ADHD suffer equally from hyperactivity compared to males, challenging the notion of a sex-dependent presentation of hyperactivity. This may lead to more accurate and timely diagnoses, reducing ADHD-related burdens and comorbidities in females.

Developmental and molecular contributions to contextual fear memory emergence in mice

Cognitive impairment is a common phenotype of neurodevelopmental disorders, but how these deficits arise remains elusive. Determining the onset of discrete cognitive capabilities facilitates studies in probing mechanisms underlying their emergence. The present study analyzed the emergence of contextual fear memory persistence (7-day memory retention) and remote memory (30-day memory retention). There was a rapid transition from postnatal day (P) 20 to P21, in which memory persistence emerged in C57Bl/6 J male and female mice. Remote memory was present at P23, but expression was not robust compared to pubertal and adult mice. Previous studies reported that following deletion of the MET receptor tyrosine kinase (MET), there are fear memory deficits in adult mice and the timing of critical period plasticity is altered in the developing visual cortex, positioning MET as a regulator for onset of contextual fear memory. Sustaining Met past the normal window of peak cortical expression or deleting Met, however, did not alter the timing of emergence of persistence or remote memory capabilities during development. Fear memory in young adults, however, was disrupted. Remarkably, compared to homecage controls, the number of FOS-expressing infragranular neurons in medial prefrontal cortex (mPFC) did not increase from contextual memory formation recall of fear conditioning at P35 but exhibited enhanced activation at P90 in male and female mice. Additionally, MET-expressing neurons were preferentially recruited at P90 compared to P35 during fear memory expression. The studies demonstrate a developmental profile of contextual fear memory capabilities. Further, developmental disruption of Met leads to a delayed functional deficit that arises in young adulthood, correlated with an increase of mPFC neuron activation during fear memory recall.

Sex Differences in Diagnosis and Treatment Timing of Comorbid Depression/Anxiety and Disease Subtypes in Patients With ADHD: A Database Study

OBJECTIVE

Our study examined the impact of sex, ADHD subtype, and comorbid illnesses (depression/anxiety) on the timing of diagnosis and treatment for ADHD.

METHOD

To analyze ADHD patients, four health databases were used to assess subtype, comorbid mood, and antidepressant or anxiolytic drug exposure. Analyses were stratified by sex and age. Standardized mean differences measured intergroup differences.

RESULTS

Females with ADHD were identified at older ages and had higher rates of depression and anxiety diagnoses and treatments before and after their initial ADHD diagnosis. Predominantly inattentive ADHD patients were diagnosed later and more likely to receive mood disorder diagnosis and treatment than hyperactive impulsive ADHD patients.

CONCLUSIONS

Results suggest a more complex ADHD presentation in females, potentially causing late diagnosis and delayed treatment.

Development and In vivo Evaluation of Atomoxetine Hydrochloride ODMTs in a Nicotine-induced Attention Deficit Hyperactivity Disorder (ADHD) Model in Rats

The current study aimed to evaluate the efficacy of orally administered rapid mini-tablets containing atomoxetine hydrochloride (ODMT) relative to the conventional capsule formulation of atomoxetine hydrochloride (ATO). To mask the bitter taste of ATO and render it more palatable for pediatric administration in individuals with Attention Deficit Hyperactivity Disorder (ADHD), an inclusion complex of ATO with β-cyclodextrin (β-CD) was synthesized. The ODMT and conventional capsule ATO formulations were administered orally to a cohort of ADHD rat pups born to nicotine-exposed dams, facilitating an in vivo efficacy assessment. Behavioral assays, including the open field test, novel object recognition test, and Barnes maze test, were conducted pre- and post-administration of the therapeutics. The outcomes suggested that the ODMT formulation, incorporating ATO-β-CD inclusion complexes, shows promise as a viable alternative to the capsule form of ATO. Conclusively, the preparation of the ATO-β-CD complexes and ODMTs leveraged a factorial experimental design, with the animal model being subjected to nicotine-induced hyperactivity to provide a unique evaluative framework for the ODMT formulation under development.

The Impact of Sex on Cognitive Control in ADHD: Girls Slow to Inhibit, Boys Inhibit Less, and Both Show Higher Response Variability

OBJECTIVE

To determine whether girls and boys with ADHD show distinct impairments in components of cognitive control across multiple tasks (go/no-go, stop signal, and flanker) and performance metrics (response speed, variability, and errors).

METHOD

A total of 300 children, ages 8 to 12 years with ADHD (n = 210, 58 girls) or typically developing (TD; n = 99, 37 girls), completed all tasks. Traditional response measures (e.g., mean and standard deviation of reaction time, inhibition errors, and stop signal reaction time) and ex-Gaussian modeling of reaction times (mu, sigma, and tau) were analyzed.

RESULTS

Girls showed intact response inhibition in the context of slower response speed, while boys made more inhibition errors and did not slow their response speed. Both girls and boys with ADHD showed higher response variability and poorer interference control than TD children.

CONCLUSION

Girls and boys with ADHD show distinct impairments in cognitive control that may be important for understanding the pathophysiology of ADHD.

Assessing adherence and clinical utility of modified goal management training for adolescents with ADHD: A pilot study

Many adolescents with attention-deficit hyperactivity disorder (ADHD) have executive functioning (EF) difficulties that contribute to academic and social-emotional challenges. This pilot explored adherence to and effectiveness of modified Goal Management Training (GMT), an EF intervention, with ADHD youth. Six adolescents with ADHD (14-17 years, 2 female) participated in a 6-session online group. Adherence was tracked via attendance and homework. Reliable change scores gaged pre-post differences on measures before and after training (primary: everyday EF and goal attainment; secondary: EF task performance, functional impairment, emotional adjustment, and self-concept). All youth attended at least 4 sessions, though homework completion was mixed. Four youth achieved their goal, some demonstrated reliable change on outcome measures, and all evidenced a reduction in impairment. Results support the feasibility of modified GMT in adolescents with ADHD and suggest that youth may benefit from this more personalized and holistic approach to EF intervention.

Selenoprotein T, a potential treatment of attention-deficit/hyperactivity disorder and comorbid pain in neonatal 6-OHDA lesioned mice

pathological pain and Attention-deficit/hyperactivity disorder (ADHD) are two complex multifactorial syndromes. The comorbidity of ADHD and altered pain perception is well documented in children, adolescents, and adults. According to pathophysiological investigations, the dopaminergic system's dysfunction provides a common basis for ADHD and comorbid pain. Growing evidence suggests that oxidative stress may be crucial in both pathologies. Recent studies revealed that a small peptide encompassing the redox-active site of selenoprotein T (PSELT), protects dopaminergic neurons and fibers as well as lesioned nerves in animal models. The current study aims to examine the effects of PSELT treatment on ADHD-like symptoms and pain sensitivity, as well as the role of catecholaminergic systems in these effects. Our results demonstrated that intranasal administration of PSELT reduced the hyperactivity in the open field, decreased the impulsivity displayed by 6-OHDA-lesioned male mice in the 5-choice serial reaction time task test and improved attentional performance. In addition, PSELT treatment significantly increased the nociception threshold in both normal and inflammatory conditions. Furthermore, anti-hyperalgesic activity was antagonized with sulpiride pre-treatment, but not by phentolamine, or propranolol pre-treatments. The present study suggests that PSELT reduces the severity of ADHD symptoms in mice and possesses potent antinociceptive effects which could be related to the involvement of D2/D3 dopaminergic receptors.

From Consensus Statement to Pills to Pixels: New Innovations in Attention-Deficit/Hyperactivity Disorder Care

Objectives: This review aims to present recent innovations and advancements in attention-deficit/hyperactivity disorder (ADHD) care, encompassing international consensus statement, new medication formulations, digital therapeutics, and neurostimulation devices. Methods: A comprehensive literature search of relevant articles published in the past five years was conducted, emphasizing the evidence base, efficacy, safety, and practical implications of these advancements. Results: The World Federation of ADHD Consensus Statement offers an updated diagnostic and treatment framework rooted in global scientific evidence. There are several newer ADHD medication formulations, including a nonstimulant (Viloxazine extended release) and the first transdermal amphetamine patch approved to treat ADHD. These options offer some unique benefits to personalize treatment based on symptom profile, lifestyle, preferences, and response. Digital tools offer additional means to restructure environments for individuals with ADHD, reducing impairment and reliance on others. In addition, digital therapeutics enhance access, affordability, personalization, and feasibility of ADHD care, complementing or augmenting existing interventions. Trigeminal nerve stimulation emerges as a well-tolerated nonpharmacological, device-based treatment for pediatric ADHD, with initial trials indicating effect sizes comparable to nonstimulant medications. Conclusions: These innovations in ADHD care represent clinically significant new treatment options and opportunities for personalized care. Health care professionals should integrate these developments into clinical practice, mindful of individual patient and family needs and preferences. Future research should assess long-term outcomes, cost-effectiveness, and acceptability of these innovations.

Prevalence of chronic and multisite pain in adolescents and young adults with ADHD: a comparative study between clinical and general population samples (the HUNT study)

Attention-deficit/hyperactivity disorder (ADHD) and chronic pain are prevalent and associated. We examined the prevalence and distribution of chronic pain in adolescents and young adults with ADHD using 9-years longitudinal data (from T1:2009-2011 to T3:2018-2019) with three time points from a clinical health survey compared to two age-matched reference population-based samples. Mixed-effect logistic regression and binary linear regression were used to estimate the probability for chronic and multisite pain at each time point and to compare the prevalence of chronic pain with the reference populations. The prevalence of chronic and multisite pain was high in those with ADHD, especially in female young adults, with highly prevalent chronic pain at 9 years of follow-up (75.9%) compared to 45.7% in females in the reference population. The probability of having pain was only statistically significant for chronic pain in males at 3 years of follow-up (41.9%, p = 0.021). Those with ADHD were at higher risk of reporting single-site and multisite pain compared to the general population at all measurement points. Longitudinal studies should be tailored to further understand the complex sex differences of comorbid chronic pain and ADHD in adolescents, exploring predictive factors of pain assessing long-term associations with bodyweight, psychiatric comorbidities, and possible mechanisms of stimulant use effects on pain.

A Nomogram for Predicting ADHD and ASD in Child and Adolescent Mental Health Services (CAMHS)

Objectives: To enhance the early detection of Attention Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) by leveraging clinical variables collected at child and adolescent mental health services (CAMHS). Methods: This study included children diagnosed with ADHD and/or ASD (n = 857). Three logistic regression models were developed to predict the presence of ADHD, its subtypes, and ASD. The analysis began with univariate logistic regression, followed by a multicollinearity diagnostic. A backward logistic regression selection strategy was then employed to retain variables with p < 0.05. Ethical approval was obtained from the local ethics committee. The models' internal validity was evaluated based on their calibration and discriminative abilities. Results: The study produced models that are well-calibrated and validated for predicting ADHD (incorporating variables such as physical activity, history of bone fractures, and admissions to pediatric/psychiatric services) and ASD (including disability, gender, special education needs, and Axis V diagnoses, among others). Conclusions: Clinical variables can play a significant role in enhancing the early identification of ADHD and ASD.

A Female-Specific Treatment Group for ADHD-Description of the Programme and Qualitative Analysis of First Experiences

Background: The diagnostics and treatment of attention-deficit/hyperactivity disorder (ADHD) in women remain insufficient. Fluctuations of reproductive hormones during the premenstrual period, postpartum period, and (peri)menopause are neglected, even though they impact ADHD symptoms and associated mood disorders. Therefore, we created a female-specific treatment group for women with ADHD and premenstrual worsening of ADHD and/or mood symptoms. Methods: We describe the group programme and underlying rationale, offering a qualitative analysis of the participants' evaluation. Results: The seven bi-weekly sessions foreground the menstrual cycle and address several ADHD-specific topics in relation to this cyclical pattern. Concurrently, women track their menstrual cycle and (fluctuating) ADHD and mood symptoms with an adjusted premenstrual calendar. In total, 18 women (25-47 years) participated in three consecutive groups. We analysed the evaluation of the last group. Participants experienced the group as a safe and welcoming space. Recognition was valued by all. The topics discussed were deemed valuable, and the structure suited them well. Completing the premenstrual calendar augmented the awareness and recognition of individual cyclical symptoms. A lifespan approach increased self-understanding. Participants took their menstrual cycle more seriously, prioritising self-acceptance and self-care. Conclusions: Exploring a cyclical approach in a group setting seems to be a positive addition to treatment for female ADHD.

Why are females less likely to be diagnosed with ADHD in childhood than males?

ADHD is less likely to be diagnosed in females than males, especially in childhood. Females also typically receive the diagnosis later than males and are less likely to be prescribed ADHD medication. Understanding why these sex differences in clinical care and treatment for ADHD occur is key to improving timely diagnosis in people affected by ADHD. This Personal View is a conceptual review synthesising literature on this topic. This publication considers potential biological explanations (eg, genetic factors), influence of diagnostic practices (eg, criteria suitability, diagnostic overshadowing, and sex-specific diagnostic thresholds), and sociocultural explanations (eg, sex differences in presentation and compensatory behaviours), for the observed sex differences in ADHD clinical practice. This Personal View also outlines future research directions for improving understanding of sex differences in recognition and diagnosis of ADHD.

Effects of comorbidity on executive functions among children with ADHD, finding trends

There is still no basic overview about the effect of various types of comorbidity in executive functions due to two main reasons: (1) the type and number of comorbidities in ADHD is significantly varied, (2) EFs are very diverse and have different neuropsychological properties. Our objective was to determine the effect of comorbid disorders (number and type) on the performance in a wide range (seven) of executive functions in a sample of children with ADHD. Fifty-five male children aged seven to nine years with ADHD were divided into six groups: G1 = ADHD only (ADHD-O), G1 = Oppositional defiant disorder (ODD), G3 = (anxiety/depressive disorder (ADD), G4 = ODD + ADD, G5 = ODD + learning disorder (LD), G6 = ODD + LD + conduct disorder (CD). The six groups exhibited different number of deficits in EFs; G1 showed only 1 deficit in contrast, G6 presented 11. Statistical analysis (ANOVA and logistic regression) identified three most affected EFs: Working memory, generation/classification of semantic categories, and inhibitory control. Alterations in EFs increased mainly in relation to the increase of the specific number and type of comorbidity. To date, no studies have addressed comorbidity from this perspective. A wide range approach of EF confirms the need to further study comorbidity in ADHD from a wide range/variety perspective and determine all possible combinations (number/type) to clarify its contribution to the complex neuropsychology functioning in ADHD.

Sex Differences in ADHD: Review and Priorities for Future Research

PURPOSE OF REVIEW

In childhood, attention-deficit/hyperactivity disorder (ADHD) is diagnosed three to 16 times more frequently in males compared to females, yet in adulthood, nearly equivalent numbers of males and females are diagnosed with ADHD. Relatively few studies have prioritized examination of sex differences in ADHD even though sex differences may have critical implications for the identification and treatment of ADHD in females and males. This review highlights current research on sex differences in ADHD across the lifespan that has emerged from cross-sectional and prospective longitudinal studies of youth, adult-ascertained samples, and registry studies.

RECENT FINDINGS

Accumulating research suggests that both males and females with ADHD experience widespread impairment across the lifespan. Some evidence of sex differences emerged, although effects have generally been modest in size. Continued research that includes females and males with ADHD is needed to clarify the nature of sex differences in ADHD. Research that focuses on equitable identification of ADHD in males and females, disentangles the effects of sex and gender, probes underlying mechanisms of sex differences, and addresses the clinical impact of sex differences in ADHD must be prioritized.

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.

Developmental and molecular contributions to contextual fear memory emergence in mice

Cognitive impairment is a common phenotype of neurodevelopmental disorders, but how these deficits arise remains elusive. Determining the onset of discrete cognitive capabilities facilitates studies in probing mechanisms underlying their emergence. The present study analyzed the emergence of contextual fear memory persistence (7-day memory retention) and remote memory (30-day memory retention). There was a rapid transition from postnatal day (P) 20 to P21, in which memory persistence emerged in C57Bl/6J male and female mice. Remote memory was present at P23, but expression was not robust compared to pubertal and adult mice. Previous studies reported that following deletion of the MET receptor tyrosine kinase (MET), there are fear memory deficits in adult mice and the timing of critical period plasticity is altered in the developing visual cortex, positioning MET as a regulator for onset of contextual fear memory. Sustaining Met past the normal window of peak cortical expression or deleting Met, however, did not alter the timing of emergence of persistence or remote memory capabilities during development. Fear memory in young adults, however, was disrupted. Remarkably, compared to homecage controls, the number of FOS-expressing infragranular neurons in medial prefrontal cortex (mPFC) did not increase from contextual memory formation recall of fear conditioning at P35 but exhibited enhanced activation at P90 in male and female mice. Additionally, MET-expressing neurons were preferentially recruited at P90 compared to P35 during fear memory expression. The studies demonstrate a developmental profile of contextual fear memory capabilities. Further, developmental disruption of Met leads to a delayed functional deficit that arises in young adulthood, correlated with an increase of mPFC neuron activation during fear memory recall.

Attention deficit hyperactivity disorder: Neuropsychological profile and study of its impact on executive functions and academic performance

INTRODUCTION

The aim of the study was to describe the neuropsychological profile of patients with attention deficit hyperactivity disorder (ADHD) and the impact of the disorder on executive functioning and academic performance.

PATIENTS AND METHODS

We conducted a retrospective observational and analytical study. The sample consisted of 24 children with a diagnosis of ADHD (aged 6-15 years) without pharmacological treatment and 24 controls without ADHD (aged 7-15 years). A comprehensive neuropsychological evaluation was carried out, encompassing major cognitive domains, in addition to assessment of executive functioning and psychopathological symptoms through the administration of questionnaires to parents and teachers.

RESULTS

The cognitive profile of the ADHD group was characterized by overall scores (including executive functions and academic abilities) in the normal range (z scores between -1 and 1), although significantly lower compared to the control group. Over half of the patients with ADHD (58%) had associated specific learning disorders. Furthermore, teachers tended to report executive function difficulties more frequently in male students.

CONCLUSIONS

In the study sample, the group of patients with ADHD exhibited cognitive performance within the normal range, although with lower scores compared to controls. Behavioural rating scales provide valuable information about functioning outside the clinic, but may yield biased results on account of the focus on externalising symptoms. The neuropsychological evaluation is a useful tool that can facilitate the diagnosis of ADHD and an effective response to the needs and characteristics of patients and families.

Prediction of brain sex from EEG: using large-scale heterogeneous dataset for developing a highly accurate and interpretable ML model

This study presents a comprehensive examination of sex-related differences in resting-state electroencephalogram (EEG) data, leveraging two different types of machine learning models to predict an individual's sex. We utilized data from the Two Decades-Brainclinics Research Archive for Insights in Neurophysiology (TDBRAIN) EEG study, affirming that gender prediction can be attained with noteworthy accuracy. The best performing model achieved an accuracy of 85% and an ROC AUC of 89%, surpassing all prior benchmarks set using EEG data and rivaling the top-tier results derived from fMRI studies. A comparative analysis of LightGBM and Deep Convolutional Neural Network (DCNN) models revealed DCNN's superior performance, attributed to its ability to learn complex spatial-temporal patterns in the EEG data and handle large volumes of data effectively. Despite this, interpretability remained a challenge for the DCNN model. The LightGBM interpretability analysis revealed that the most important EEG features for accurate sex prediction were related to left fronto-central and parietal EEG connectivity. We also showed the role of both low (delta and theta) and high (beta and gamma) activity in the accurate sex prediction. These results, however, have to be approached with caution, because it was obtained from a dataset comprised largely of participants with various mental health conditions, which limits the generalizability of the results and necessitates further validation in future studies. . Overall, the study illuminates the potential of interpretable machine learning for sex prediction, alongside highlighting the importance of considering individual differences in prediction sex from brain activity.

Female-specific pharmacotherapy in ADHD: premenstrual adjustment of psychostimulant dosage

Objective

Attention-Deficit/Hyperactivity Disorder (ADHD) is a common neurodevelopmental condition which is underdiagnosed and undertreated in women. For decades, the ADHD field has called for more insight into female-specific therapy. Preliminary findings postulate that changes in sex hormones during the menstrual cycle may influence the effectiveness of psychostimulant medication. Yet, pharmacotherapeutic interventions tailored to women with ADHD remain scarce. Previously, our group showed an increase in mood symptoms in the premenstrual week in women with ADHD. Premenstrual worsening of depressive and ADHD symptoms represent a treatment challenge. In our adult ADHD clinic, we noted several women describing exacerbation of their ADHD and depressive symptoms in the premenstrual week and/or insufficient effect of their established dosage of psychostimulant. We responded to the need expressed by these women by increasing their stimulant dosage in the premenstrual week, while monitoring the response and side effects.

Methods

This community case study of nine consecutive women being treated for ADHD and co-occurring conditions (including depression and premenstrual dysphoric disorder), reports our local experience of increasing the individually prescribed psychostimulant dosage during the premenstrual period. We methodically monitored the effect of this increased dosage on ADHD symptoms, mood and somatic symptoms for the following 6-24 months.

Results

With premenstrual dose elevation, all nine women experienced improved ADHD and mood symptoms with minimal adverse events. Premenstrual inattention, irritability and energy levels improved, and now resembled the other non-premenstrual weeks more closely. All women decided to continue with the elevated premenstrual pharmacotherapy.

Discussion

Our preliminary results demonstrate potential benefits of increasing premenstrual psychostimulant dosage in women with ADHD, experiencing premenstrual worsening of ADHD and mood symptoms. The results concur with previous findings of diminished response to amphetamines in the late luteal phase. Increased dosage may help combat premenstrual worsening of cognitive and emotional symptoms in women with ADHD, with significant clinical implications. Better management of premenstrual ADHD and mood symptoms in vulnerable women can improve treatment outcome and meet an unmet need. However, implementation should be individually explored. Further investigation of luteal phase psychostimulant dose adjustment is required for safe, optimal and individualised treatment for women with ADHD.

Experiences of children and adolescents with attention-deficit/hyperactivity disorder taking methylphenidate

To improve clinical counselling for adolescents about the use of stimulant medication, it is crucial to understand the experiences of young people diagnosed with attention-deficit/hyperactivity disorder (ADHD) who are taking such treatment. For this narrative review, five databases were searched for studies investigating the personal experiences of control issues in adolescents diagnosed with ADHD taking methylphenidate. We extracted the data using NVivo 12 and interpretatively synthesized them according to the procedures of thematic analysis. Interviewed youngsters spontaneously put forward self-experiences about self-esteem and sense of control, although these issues were rarely explicitly addressed in the research question. The overarching theme in these studies was 'improving the self'. Two subthemes emerged: (1) medication sometimes delivered on its promise to improve the self, but regularly it did not; and (2) youngsters felt pressurized to conform to behavioural norms and comply with the medication use that adults had decided on. To genuinely involve youngsters diagnosed with ADHD for whom stimulant medication is prescribed in the shared decision-making process, we recommend to specifically involve them in a dialogue on the medication's potential effects on their self-experiences. This will allow them to feel at least partly in control of their body and life, and less pressurized to conform to others' norms.

ADHD-related sex differences in frontal lobe white matter microstructure and associations with response control under conditions of varying cognitive load and motivational contingencies

Children with attention-deficit/hyperactivity disorder (ADHD) demonstrate reduced response inhibition, increased response time variability, and atypical frontal lobe white matter microstructure with emerging evidence of sex differences. This study aims to examine whether frontal lobe white matter microstructure is differentially impacted in ADHD by sex and whether this relates to Go/No-Go (GNG) task performance. Diffusion tensor imaging (DTI) from 187 children (8-12 years), including ADHD (n = 94) and typically developing controls (TD; n = 93). Participants completed three GNG tasks with varying cognitive demands and incentives (standard, cognitive, and motivational). Fractional anisotropy (FA) was examined as an index of white matter microstructure within bilateral frontal lobe regions of interest. Children with ADHD showed reduced FA in primary motor (M1) and supplementary motor area (SMA) regardless of sex. Sex-based dissociation for the effect of diagnosis was observed in medial orbitofrontal cortex (mOFC), with higher FA in girls with ADHD and lower FA in boys with ADHD. Both diagnosis and sex contributed to performance on measures of response inhibition and reaction time (RT) variability, with all children with ADHD demonstrating poorer performance on all GNG tasks, but boys with ADHD demonstrating more impulsivity on standard and motivational behavioral paradigms compared to girls with ADHD. Analyses revealed associations between reduced FA in M1, SMA, and mOFC and increased response inhibition and RT variability with some sex-based differences. These findings provide novel insights regarding the brain basis of ADHD and associated impairments in response inhibition and RT variability, and contribute to our understanding of sexual dimorphic behavioral outcomes.

A systematic meta-review of systematic reviews on attention deficit hyperactivity disorder

BACKGROUND

There are now hundreds of systematic reviews on attention deficit hyperactivity disorder (ADHD) of variable quality. To help navigate this literature, we have reviewed systematic reviews on any topic on ADHD.

METHODS

We searched MEDLINE, PubMed, PsycINFO, Cochrane Library, and Web of Science and performed quality assessment according to the Joanna Briggs Institute Manual for Evidence Synthesis. A total of 231 systematic reviews and meta-analyses met the eligibility criteria.

RESULTS

The prevalence of ADHD was 7.2% for children and adolescents and 2.5% for adults, though with major uncertainty due to methodological variation in the existing literature. There is evidence for both biological and social risk factors for ADHD, but this evidence is mostly correlational rather than causal due to confounding and reverse causality. There is strong evidence for the efficacy of pharmacological treatment on symptom reduction in the short-term, particularly for stimulants. However, there is limited evidence for the efficacy of pharmacotherapy in mitigating adverse life trajectories such as educational attainment, employment, substance abuse, injuries, suicides, crime, and comorbid mental and somatic conditions. Pharmacotherapy is linked with side effects like disturbed sleep, reduced appetite, and increased blood pressure, but less is known about potential adverse effects after long-term use. Evidence of the efficacy of nonpharmacological treatments is mixed.

CONCLUSIONS

Despite hundreds of systematic reviews on ADHD, key questions are still unanswered. Evidence gaps remain as to a more accurate prevalence of ADHD, whether documented risk factors are causal, the efficacy of nonpharmacological treatments on any outcomes, and pharmacotherapy in mitigating the adverse outcomes associated with ADHD.

Beyond the mean: Distributional differences in earnings and mental health in young adulthood by childhood health histories

Research on the long-term effects of health in early life has predominantly relied on parametric methods to assess differences between groups of children. However, this approach leaves a wealth of distributional information untapped. The objective of this study was to assess distributional differences in earnings and mental health in young adulthood between individuals who suffered a chronic illness in childhood compared to those who did not using the non-parametric relative distributions framework. Using data from the Panel Study of Income Dynamics, we find that young adults who suffered a chronic illness in childhood fare worse in terms of earnings and mental health scores in adulthood, particularly for individuals reporting a childhood mental health/developmental disorder. Covariate decompositions suggest that chronic conditions in childhood may indirectly affect later outcomes through educational attainment: had the two groups had similar levels of educational attainment, the proportion of individuals with a report of a chronic condition in childhood in the lower decile of the relative earnings distribution would have been reduced by about 20 percentage points. Findings may inform policy aimed at mitigating longer run effects of health conditions in childhood and may generate hypotheses to be explored in parametric analyses.

Sex representation in neurodegenerative and psychiatric disorders' preclinical and clinical studies

Many studies show the importance of biological sex for the onset, progression, and response to treatment in brain disorders. In line with these reports, health agencies have requested that all trials, both at the clinical and preclinical level, use a similar number of male and female subjects to correctly interpret the results. Despite these guidelines, many studies still tend to be unbalanced in the use of male and female subjects. In this review we consider three neurodegenerative disorders: Alzheimer's disease, Parkinson's disease, Amyotrophic lateral sclerosis, and three psychiatric disorders: Depression, Attention Deficit Hyperactivity Disorder, and Schizophrenia. These disorders were chosen because of their prevalence and their recognized sex-specific differences in onset, progression, and response to treatment. Alzheimer's disease and Depression demonstrate higher prevalence in females, whereas Parkinson's Disease, Amyotrophic lateral sclerosis, Attention Deficit Hyperactivity Disorder, and schizophrenia show higher prevalence in males. Results from preclinical and clinical studies examining each of these disorders revealed sex-specific differences in risk factors, diagnostic biomarkers, and treatment response and efficacy, suggesting a role for sex-specific therapies in neurodegenerative and neuropsychiatric disorders. However, the qualitative analysis of the percentage of males and females enrolled in clinical trials in the last two decades shows that for most of the disorders, there is still a sex bias in the patients' enrolment.

Short form Conners' Adult ADHD Rating Scales: Factor structure and measurement invariance by sex in emerging adults

INTRODUCTION

The short version of the Conners' Adult ADHD Rating Scales (CAARS-S:S) is a self-report measure used to identify symptoms of Attention Deficit/Hyperactivity Disorder (ADHD) during adulthood. However, its psychometric properties specifically in emerging adults, or the transitional age group between adolescence and adulthood, remain understudied. This study aimed to validate the factor structure of the CAARS-S:S in a sample of emerging adults.

METHOD

The CAARS-S:S measure was completed by adults (n = 591) aged 18 to 29 located in English-speaking countries, including Australia, Canada and the United States. Confirmatory factor analysis was used to test a four-factor model of Inattention/Memory Problems, Hyperactivity/Restlessness, Impulsivity/Emotional Lability and Problems with Self-Concept, as well as the model's invariance by sex. Sex was also included as a covariate in the model to examine differences in males' and females' scores on each factor.

RESULTS

Overall, the four-factor structure fit the data and was invariant across males and females. All factors demonstrated high internal reliability (average ωt and α = .86). It was observed that males tended to score higher on Inattention/Memory Problems while females scored higher on Problems with Self-Concept.

CONCLUSION

This research establishes the psychometric properties of the CAARS-S:S, placing greater confidence in using it to screen for ADHD symptoms in emerging adults living in a Westernized cultural context. The detailed findings of this research, implications for the use of the CAARS-S:S in this age group and potential future directions for examining the properties of the measure are discussed.

Martial Arts and Cognitive Control in Children with Attention-Deficit Hyperactivity Disorder and Children Born Very Preterm: A Combined Analysis of Two Randomized Controlled Trials

INTRODUCTION

Very preterm birth and attention-deficit hyperactivity disorder (ADHD) are associated with impairments in response inhibition that often persist beyond childhood. Athletes skilled in martial arts show a neurocognitive profile that is associated with an improved inhibition processing stream, suggesting that engagement in this kind of sport has the potential to reduce impairments in this cognitive function. We investigated the behavioral and neurocognitive effects of judo training on response inhibition in children born very preterm and children with ADHD by a combined analysis of two randomized controlled trials.

METHODS

In both the CHIPMANC ( n = 65) and JETPAC ( n = 63) studies, participants were randomly allocated to a waitlist or a 12-wk judo training program in a 1:1 ratio. At pretest and posttest, participants completed a Go/NoGo task, the Movement Assessment Battery for Children-2 and a physical work capacity test on a bicycle ergometer. During the cognitive task, event-related potentials (N2, P3a, P3b) were recorded via electroencephalography.

RESULTS

The effects of the judo training were moderated by the study group. In contrast to children with ADHD (JETPAC), judo training reduced the commission error rate on the Go/NoGo task and increased the P3a amplitude in children born very preterm (CHIPMANC). No treatment effects were found for N2, P3b and physical fitness outcomes.

CONCLUSIONS

The neurodevelopmental condition influences the cognitive benefits of judo training. Whereas judo may be ineffective in children with ADHD, children born very preterm can expect improved response inhibition due to a more effective engagement of focal attention to resolve the task-related response conflict.

Sex and gender in neurodevelopmental conditions

Health-related conditions often differ qualitatively or quantitatively between individuals of different birth-assigned sexes and gender identities, and/or with different gendered experiences, requiring tailored care. Studying the moderating and mediating effects of sex-related and gender-related factors on impairment, disability, wellbeing and health is of paramount importance especially for neurodivergent individuals, who are diagnosed with neurodevelopmental conditions with uneven sex/gender distributions. Researchers have become aware of the myriad influences that sex-related and gender-related variables have on the manifestations of neurodevelopmental conditions, and contemporary work has begun to investigate the mechanisms through which these effects are mediated. Here we describe topical concepts of sex and gender science, summarize current knowledge, and discuss research and clinical challenges related to autism, attention-deficit/hyperactivity disorder and other neurodevelopmental conditions. We consider sex and gender in the context of epidemiology, behavioural phenotypes, neurobiology, genetics, endocrinology and neighbouring disciplines. The available evidence supports the view that sex and gender are important contributors to the biological and behavioural variability in neurodevelopmental conditions. Methodological caveats such as frequent conflation of sex and gender constructs, inappropriate measurement of these constructs and under-representation of specific demographic groups (for example, female and gender minority individuals and people with intellectual disabilities) limit the translational potential of research so far. Future research and clinical implementation should integrate sex and gender into next-generation diagnostics, mechanistic investigations and support practices.

ADHD and associated psychopathology in older adults in a German community sample

Attention deficit hyperactivity disorder (ADHD) is still a neglected disorder in older adults. The aim of the present study was to examine the prevalence and symptomatology of ADHD and associated psychopathology in adults aged 40-80 years in a German community sample. We examined 539 participants in two age groups: (1) 40-59 years old (n = 256) and (2) 60-80 years old (n = 283). To assess ADHD in both childhood and adulthood as well as current psychopathological impairments, we used self-report instruments and corresponding observer reports. We examined group differences between age groups and between ADHD and non-ADHD groups. The prevalence of ADHD in the total sample was 2.6% with no significant differences between the two age groups (40-59 years: 3.1% vs. 60-80 years: 2.1%). Although differences emerged in impulsivity/emotional lability and self-concept problems, overall ADHD symptom ratings did not differ between the age groups. The ADHD group showed more psychopathological peculiarities compared to individuals without ADHD with medium-to-large effect sizes. Self-reports and observer reports showed good concordance in the assessment of ADHD and comorbid psychopathological symptoms. Regarding current ADHD symptomatology, in 92.1%, self-report was corroborated by observer's information. Our findings underline that ADHD symptoms are relevant across the lifespan. Augmenting self-reports with observer reports could increase the assessment quality of ADHD. For successful treatment, clinicians should also focus on additional psychopathological impairments and comorbidities in older adults with ADHD.

Association between Hyperactivity and SSB Consumption in Schoolchildren: A Cross-Sectional Study in China

Sugar-sweetened beverages (SSBs) consumption has risen significantly, which may lead to various health problems. Studies about the association between SSBs and attention-deficit/hyperactivity disorder (ADHD) in children are rare and inconsistent. We have used the two-stage cluster sampling method to select 6541 students aged 6-12. We further investigated their basic information and SSB intake. Teachers' questionnaires and parents' questionnaires were used to evaluating the hyperactive behaviors in children. We examined the associations between SSB consumption and hyperactivity index (HI) by adopting the censored least absolute deviation (CLAD) estimator. Then, we further evaluated the impacts of sex and age on the association between SSB intake and hyperactivity. Children who weekly drank SSB two or more times were associated with 0.05 (0.04, 0.07) and 0.04 (0.02, 0.06) higher scores of ln (HI+1) reported by teachers and parents, respectively, compared to non-consumers children (p for trend < 0.05). A stronger association between SSB intake and hyperactivity occurred in girls and old children. (p for interaction < 0.05). SSB intake has a positive correlation with the risk of hyperactivity in children, and the frequency of SSB consumption and hyperactivity have a dose-response relationship.

Sex-Specific Neurocognitive Impairment

This article explores sex-specific neurocognitive impairment. It first defines relevant terms such as gender and sex. Next, it describes the nature of the problem including under-representation of women and other gender and sexual minorities in neuroscience research, including cognitive studies. A biopsychosocial framework is employed to account for structural and social determinants of health in sex/gender-specific neurocognitive impairment. Issues in assessment including the use of gender/sex-specific normative data are also discussed. Lastly, the article covers the current state of research as it relates to sex/gender-specific neurocognitive impairment across a range of medical conditions including neurodegenerative diseases and coronavirus disease-2019.

Targeting Neuroinflammation with Abscisic Acid Reduces Pain Sensitivity in Females and Hyperactivity in Males of an ADHD Mice Model

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental syndrome characterized by dopaminergic dysfunction. In this study, we aimed to demonstrate that there is a link between dopaminergic deficit and neuroinflammation that underlies ADHD symptoms. We used a validated ADHD mice model involving perinatal 6-OHDA lesions. The animals received abscisic acid (ABA), an anti-inflammatory phytohormone, at a concentration of 20 mg/L (drinking water) for one month. We tested a battery of behavior tests, learning and memory, anxiety, social interactions, and pain thresholds in female and male mice (control and lesioned, with or without ABA treatment). Postmortem, we analyzed microglia morphology and Ape1 expression in specific brain areas related to the descending pain inhibitory pathway. In females, the dopaminergic deficit increased pain sensitivity but not hyperactivity. In contrast, males displayed hyperactivity but showed no increased pain sensitivity. In females, pain sensitivity was associated with inflammatory microglia and lower Ape1 levels in the anterior cingulate cortex (ACC) and posterior insula cortex (IC). In addition, ABA treatment alleviated pain sensitivity concomitant with reduced inflammation and normalized APE1. In males, ABA reduced hyperactivity but had no significant effect on inflammation in these areas. This is the first study proving a sex-dependent association between dopamine dysfunction and inflammation in specific brain areas, hence leading to different behavioral outcomes in a mouse model of ADHD. These findings provide new clues for potential treatments for ADHD.

Data-Driven Methods for Predicting ADHD Diagnosis and Related Impairment: The Potential of a Machine Learning Approach

Current diagnostic criteria for ADHD include several symptoms that highly overlap in conceptual meaning and interpretation. Additionally, inadequate sensitivity and specificity of current screening tools have hampered clinicians' ability to identify those at risk for related outcomes. Using machine learning techniques, the current study aimed to propose a novel algorithm incorporating key ADHD symptoms to predict concurrent and future (i.e., five years later) ADHD diagnosis and related impairment levels. Participants were 399 children with and without ADHD; multiple informant measures of ADHD symptoms, global impairment, academic performance, and social skills were included as part of an accelerated longitudinal design. Results suggested eight symptoms as most important in predicting impairment outcomes five years later: (1) Has difficulty sustaining attention in tasks or play activities, (2) Does not follow through on instructions and fails to finish work, (3) Has difficulty organizing tasks and activities, (4) Avoids tasks (e.g., schoolwork, homework) that require sustained mental effort, (5) Is often easily distracted, (6) Is often forgetful in daily activities, (7) Fidgets with hands or feet or squirms in seat, and (8) Interrupts/intrudes on others. The algorithm comprising this abbreviated list of symptoms performed just as well as or significantly better than one comprising all 18 symptoms in predicting future global impairment and academic performance, but not social skills. It also predicted concurrent and future ADHD diagnosis with 81-93% accuracy. Continued development of screening tools will be key to ensuring access to clinical services for youth at risk for ADHD.

Associations between Chronic Pain and Attention-Deficit Hyperactivity Disorder (ADHD) in Youth: A Scoping Review

Background: Chronic pain and ADHD are common conditions among youth that negatively impact functioning. This review fills a critical gap by summarizing current research on chronic pain and ADHD comorbidity, and it proposes a conceptual model of shared associations and underlying mechanisms. Objective: The aims of the current study were to: (1) review the extant literature and present estimates of the prevalence of comorbid non-headache chronic pain and ADHD in youth and (2) describe potential shared mechanisms for ADHD and chronic non-headache pain in youth. We also outline future directions to inform future research and interventions directed to youth with comorbid pain and ADHD. Design: A scoping review of the literature was performed in MEDLINE, PsycInfo, and Cochrane Database of Systematic Reviews using a wide range of search terms related to pain, Attention Deficit-Hyperactivity Disorder, childhood, adolescence, and young adulthood. Results: Eleven published studies were included in the review. These studies examined the prevalence of chronic pain among youth with ADHD, the prevalence of ADHD in chronic pain samples, and the association between chronic pain and ADHD among youth. Findings revealed results from studies indicating a higher prevalence of ADHD among youth with chronic pain and a higher prevalence of chronic pain in samples of youth with ADHD. Conclusions: Findings from this scoping review suggest an association between chronic pain and ADHD among youth. Little research was found to examine the etiology of this association. Future studies should examine underlying mechanisms of comorbid chronic pain and ADHD.

Attention-deficit/hyperactivity disorder and white matter microstructure: the importance of dimensional analyses and sex differences

Background

Attention-deficit/hyperactive disorder (ADHD) has substantial heterogeneity in clinical presentation. A potentially important clue may be variation in brain microstructure. Using fractional anisotropy (FA), previous studies have produced equivocal results in relation to ADHD. This may be due to insufficient consideration of possible sex differences and ADHD's multi-componential nature.

Methods

Using whole-brain analyses, we investigated the association between FA and both ADHD diagnosis and ADHD symptom domains in a well-characterized, ADHD (n = 234; 32% female youth) and non-ADHD (n = 177; 52% female youth), case-control cohort (ages 7-12). Sex-specific effects were tested.

Results

No ADHD group differences were found using categorical assessment of ADHD without consideration of moderators. However, dimensional analyses found total symptoms were associated with higher FA in the superior corona radiata. Further, inattention symptoms were associated with higher FA in the corpus callosum and ansa lenticularis, and lower FA in the superior longitudinal fasciculus, after control for overlap with hyperactivity-impulsivity. Hyperactivity-impulsivity symptoms were associated with higher FA in the superior longitudinal fasciculus, and lower FA in the superior cerebellar peduncles, after control for overlap with inattention. Meanwhile, both categorical and dimensional analyses revealed ADHD-by-sex interactions (voxel-wise p < 0.01). Girls with ADHD had higher FA, but boys with ADHD had lower FA (or no effect), compared to their same-sex peers, in the bilateral anterior corona radiata. Further, higher ADHD symptom severity was associated with higher FA in girls, but lower FA in boys, in the anterior and posterior corona radiata and cerebral peduncles.

Conclusions

ADHD symptom domains appear to be differentially related to white matter microstructure, highlighting the multi-componential nature of the disorder. Further, sex differences will be crucial to consider in future studies characterizing ADHD-related differences in white matter microstructure.

Impairments in Emotion Recognition and Positive Emotion Regulation Predict Social Difficulties in Adolescent With ADHD

BACKGROUND

Emotional dysregulation, poor emotion recognition and impaired response inhibition have been highlighted as potential contributors to social difficulties in adolescents with attention-deficit/hyperactivity disorder (ADHD). It is currently unknown how these areas of impairment relate to one another; therefore, this study aims to identify the areas of emotion regulation which are associated with social difficulties in adolescents with ADHD, and determine whether emotion regulation mediates the relationship between deficits in response inhibition and emotion recognition, and social functioning, in this cohort.

METHODS

Thirty Australian adolescents (Male = 21) with ADHD completed measures of response inhibition, emotion recognition, and emotion regulation.

RESULTS

Positive emotion regulation was significantly associated with social difficulties. Although emotion recognition significantly predicted social difficulties, there was no relationship between emotion recognition and emotion regulation in this sample, ruling out emotion regulation as a mediator of emotion recognition and social difficulties. Whilst response inhibition was significantly correlated with positive emotion regulation, positive emotion regulation did not mediate the relationship between response inhibition and social difficulties.

CONCLUSIONS

Difficulties recognising and regulating emotions appear to independently contribute to social difficulties in adolescents with ADHD. Interventions to increase emotional understanding and developing strategies to down-regulate positive emotions may be beneficial.

Does rapid rebound height growth come at a neurocognitive cost for previously institutionalized youth?

BACKGROUND

Height growth faltering is associated with less optimal behavioral outcomes and educational achievement. Although catch-up growth after growth delay may result in developmental gains, it may also present as a double-edged sword, with consequences for neurocognitive functioning such as symptoms of inattention and hyperactivity. As previously institutionalized (PI) children experience height delays at adoption and catch-up growth after adoption, they provide a cohort to test associations between catch-up growth and attention deficit hyperactivity disorder (ADHD) symptoms.

METHODS

This study used latent growth curve modeling to examine how catch-up in height-for-age growth is related to attention problems in a population of PI youth followed from adoption in infancy through kindergarten. Participants were assessed within three months of arrival into their families (age at entry: 18-36 months). Anthropometrics were measured four times, approximately 7 months apart. Two visits measured behavioral outcomes with parent and teacher reports of ADHD, internalizing, and externalizing symptoms at age 5 and kindergarten.

RESULTS

The slope of growth in height z-scores, but not the intercept, was positively associated with parent- and teacher-reported ADHD symptoms in children. A one standard deviation increase in the slope of height z-scores across four assessments was associated with a 0.252 standard deviation increase in ADHD symptoms after controlling for internalizing and externalizing problems, iron status, duration of institutional care, sex, and age. The slope of growth was also associated with internalizing but not externalizing symptoms.

CONCLUSIONS

This study demonstrates that PI children exhibit individual trajectories of height growth postadoption. Higher rates of change in height-for-age growth were associated with increased ADHD symptoms. These results suggest that catch-up growth comes 'at the cost' of poor attention regulation and hyperactive behavior.

Sex Differences in Substance Use, Prevalence, Pharmacological Therapy, and Mental Health in Adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD)

Sex differences are poorly studied within the field of mental health, even though there is evidence of disparities (with respect to brain anatomy, activation patterns, and neurochemistry, etc.) that can significantly influence the etiology and course of mental disorders. The objective of this work was to review sex differences in adolescents (aged 13–18 years) diagnosed with ADHD (according to the DSM-IV, DSM-IV-TR and DSM-5 criteria) in terms of substance use disorder (SUD), prevalence, pharmacological therapy and mental health. We searched three academic databases (PubMed, Web of Science, and Scopus) and performed a narrative review of a total of 21 articles. The main conclusions of this research were (1) girls with ADHD are more at risk of substance use than boys, although there was no consensus on the prevalence of dual disorders; (2) girls are less frequently treated because of underdiagnosis and because they are more often inattentive and thereby show less disruptive behavior; (3) together with increased impairment in cognitive and executive functioning in girls, the aforementioned could be related to greater substance use and poorer functioning, especially in terms of more self-injurious behavior; and (4) early diagnosis and treatment of ADHD, especially in adolescent girls, is essential to prevent early substance use, the development of SUD, and suicidal behavior.

Topographical relocation of adolescent sleep spindles reveals a new maturational pattern in the human brain

Current theories of human neural development emphasize the posterior-to-anterior pattern of brain maturation. However, this scenario leaves out significant brain areas not directly involved with sensory input and behavioral control. Suggesting the relevance of cortical activity unrelated to sensory stimulation, such as sleep, we investigated adolescent transformations in the topography of sleep spindles. Sleep spindles are known to be involved in neural plasticity and in adults have a bimodal topography: slow spindles are frontally dominant, while fast spindles have a parietal/precuneal origin. The late functional segregation of the precuneus from the frontoparietal network during adolescence suggests that spindle topography might approach the adult state relatively late in development, and it may not be a result of the posterior-to-anterior maturational pattern. We analyzed the topographical distribution of spindle parameters in HD-EEG polysomnographic sleep recordings of adolescents and found that slow spindle duration maxima traveled from central to anterior brain regions, while fast spindle density, amplitude and frequency peaks traveled from central to more posterior brain regions. These results provide evidence for the gradual posteriorization of the anatomical localization of fast sleep spindles during adolescence and indicate the existence of an anterior-to-posterior pattern of human brain maturation.

Annual Research Review: Attention-deficit/hyperactivity disorder in girls and women: underrepresentation, longitudinal processes, and key directions

Attention-deficit/hyperactivity disorder (ADHD) - and its underlying behavioral dimensions of inattention and hyperactivity-impulsivity - have been understudied in females. We first cover the conceptual issues of prevalence, diagnostic practices, diversity, comorbidity, and causal factors, plus forces limiting awareness of ADHD in females. After a narrative review of cross-sectional and longitudinal findings, we conclude the following. (a) Girls meet diagnostic criteria for ADHD at just under half the rates of boys, a ratio that becomes much closer to equal by adulthood. (b) Girls and women with ADHD show a predominance of inattention and associated internalizing problems; boys and men display greater levels of hyperactive-impulsive symptoms and associated externalizing problems. (c) Sex differences in ADHD symptoms and related outcomes depend heavily on the clinical versus nonreferred nature of the samples under investigation. (d) Females with ADHD experience, on average, serious impairments, with a particularly heightened risk for problems in close relationships and engagement in self-harm. (e) Clinicians may overlook symptoms and impairments in females because of less overt (but still impairing) symptom manifestations in girls and women and their frequent adoption of compensatory strategies. Our review of predictors and mediators of adult outcomes highlights (a) the potential for heterotypically continuous pathways in females with childhood ADHD and (b) developmental progressions to self-harm, intimate partner violence, unplanned pregnancy, and comorbid psychopathology. Focusing on ADHD in females is necessary to characterize causal and maintaining mechanisms with accuracy and to foster responsive interventions, as highlighted in our closing list of clinical implications and research priorities.

School Achievement in Early Adolescence Is Associated With Students' Self-Perceived Executive Functions

The primary aim of this study was to investigate the relation between self-perceived executive functions (EFs) and the school achievement of young adolescents (aged 10-12 years), while controlling for parental education and sex. We specifically focused on executive aspects of daily life behavior and the higher-order EFs, as measured with self-report, rather than on the more basic EFs which have been the primary focus of prior investigations. In two independent samples of sixth graders (N > 200 each), students evaluated their EFs on a self-report questionnaire, the Amsterdam Executive Functioning Inventory. School achievement in the domains of mathematics and reading comprehension were evaluated with nationally used, norm-based achievement tests. Results revealed that the self-perceived EFs of young adolescents were significantly correlated with their school achievement in both study samples. School achievement was also correlated with the level of parental education, but the factor sex did not have such influence. In study 1, self-perceived EFs explained additional variance in school achievement, while controlling for parental education and sex. In study 2, this was only the case for the most robust measure of school achievement, i.e., the end-of-primary-school final achievement test. Furthermore, besides the relation with achievement tests, we also found a relation between self-perceived EFs and teacher ratings behavioral problems in the classroom. Together, our findings imply that young students can properly reflect on the effectiveness and appropriateness of their EFs in a way that is relevant to their academic achievement and classroom behavior. The findings underscore the importance of considering the development of EFs and parental education in the evaluation of academic achievements in early adolescence.

A Gene-Environment Interaction Study of Polygenic Scores and Maltreatment on Childhood ADHD

This study explored whether maltreatment moderates the association of polygenic risk for ADHD. Because individuals with low polygenic scores (PGS) for ADHD were previously shown to have better than expected functional outcomes (i.e., cognitive, mental health, social-emotional) than individuals with middle or high ADHD PGS, we hypothesized low ADHD PGS may confer a protective effect from maltreatment in the development of ADHD. Data were from participants with phenotypic and genotypic data in the National Longitudinal Study of Adolescent to Adult Health (Add Health; n = 4,722). ADHD PGS were generated from the most recent genome-wide association study on ADHD and categorized into three groups (i.e., low, medium, high) using empirically determined cut-points. A maltreatment factor score was derived from five forms of self-reported maltreatment experiences prior to age 18. ADHD PGS and maltreatment were positively associated with ADHD symptoms, as expected. However, no interaction between ADHD PGS and maltreatment on ADHD symptoms was detected. Despite the increase in predictive power afforded by PGS, the lack of an interaction between ADHD PGS and maltreatment on ADHD symptoms converges with an emerging body of PGS studies that have also failed to detect PGS-environment interplay in mental disorders. We discuss possible reasons for this pattern of results and offer alternative methods for future research in understanding gene-environment interactions.

Towards equitable diagnoses for autism and attention-deficit/hyperactivity disorder across sexes and genders

PURPOSE OF REVIEW

Sex/gender-related factors contribute to contextual issues influencing the recognition of autism and attention-deficit/hyperactivity disorder (ADHD), and modulate how neurodevelopmental characteristics are manifested. This review summarizes the empirical literature to provide directions for improving clinical diagnostic practices.

RECENT FINDINGS

Timing of autism and/or ADHD diagnosis, particularly in girls/women, is related to the individual's developmental characteristics and co-occurring diagnoses, and expectancy, alongside gender stereotype biases, of referral sources and clinicians. This is further compounded by sex and gender modulations of behavioural presentations. The emerging 'female autism phenotype' concept may serve as a helpful illustration of nuanced autism phenotypes, but should not be viewed as essential features of autism in a particular sex or gender. These nuanced phenotypes that can present across sexes and genders include heightened attention to socially salient stimuli, friendship and social groups, richness in language expression, and more reciprocal behaviours. The nuanced female-predominant ADHD phenotypes are characterized by subtle expressions in hyperactivity-impulsivity (e.g., hyper-verbal behaviours). Optimizing neurodevelopmental diagnoses across sexes and genders also requires an understanding of sex-related and gender-related variations in developmental trajectories, including compensation/masking efforts, and the influences of co-occurring conditions on clinical presentations.

SUMMARY

Equitable diagnoses across sexes and genders for autism and ADHD require understanding of the nuanced presentations and the Gestalt clinical-developmental profiles, and addressing contextual biases that influence diagnostic practices.

Brain structural changes and the development of interference control in children with ADHD: The predictive value of physical activity and body mass index

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Children with ADHD show deficits in interference control during preadolescence.

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Abnormalities in gray-white matter ratio contributed contribute to these deficits.

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Higher physical activity and lower body mass index predict higher interference control.

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Gray-white matter ratio underlies the predictive value of body mass index.

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Brain structure does not explain the predictive value of physical activity.

Background

Children with ADHD face deficits in interference control due to abnormalities in brain structure. A low body mass index and high physical activity are factors promoting brain health and may have the potential to reduce ADHD-related cognitive deficits. We aimed to investigate the predictive values of ADHD, body mass index and physical activity for interference control and the potential mediation of these associations by brain structure.

Method

At 9 and 11 years, 4576 children with ADHD and neurotypical peers from the ABCD-cohort completed a Flanker task, anthropometric assessments and reported physical activity. Additionally, T1- and T2-weighted magnet resonance images were collected at both measurement time points.

Results

ADHD, lower physical activity and higher body mass index at baseline predicted lower interference control. Gray matter volume, surface area and gray-white matter ratio contributed to interference control. The longitudinal association between body mass index and interference control was mediated by gray-white-matter ratio. This mediating effect was stronger for children with ADHD than neurotypical peers and mainly restricted to regions associated with cognitive control.

Conclusion

The maintenance of a lower body mass index contributes to interference control by a tendency to normalize regional alterations in grey-white-matter ratio. Being compliant with physical activity also promises higher interference control, but brain structure does not seem to underlie this association.

Prevalence and correlates of attention deficit hyperactivity disorder among college students in Jeddah, Saudi Arabia

Background:

Childhood attention deficit hyperactivity disorder (ADHD) is commonly diagnosed in Saudi Arabia, but there is negligible evidence regarding adult ADHD in college students.

Objective:

To determine the prevalence and correlates of ADHD among undergraduates at King Abdulaziz University, Jeddah, Saudi Arabia.

Methods:

In this cross-sectional study, 2280 undergraduate students from 11 colleges at King Abdulaziz University, one of the largest university in Saudi Arabia, were approached in person with a questionnaire that elicited information regarding demographics, education, psychiatric history, health behaviors, and ADHD. A validated Arabic version of the Adult ADHD Self-Report Scale was used.

Results:

A total of 2059 students (90%) completed the questionnaire (mean age: 21.2 years). Almost one-tenth (11.9%) of the sample met the criteria for adult ADHD; only 6.5% had been diagnosed with ADHD in childhood and <1% (0.8%) had taken medication for the same. Multivariate analyses revealed that high family income, low grade in the last semester, parental divorce, diagnosis of childhood ADHD, prior diagnosis of depression, greater severity of current depression and anxiety, and cigarette smoking increased the likelihood of adult ADHD.

Conclusion:

A notable proportion of students in this study had suspected adult ADHD. Early evaluation of students with ADHD and identification of those at risk may potentially help in improving their academic performance and quality of life.

Network analysis of 18 attention-deficit/hyperactivity disorder symptoms suggests the importance of "Distracted" and "Fidget" as central symptoms: Invariance across age, gender, and subtype presentations

The network theory of mental disorders conceptualizes psychiatric symptoms as networks of symptoms that causally interact with each other. Our present study aimed to explore the symptomatic structure in children with attention-deficit/hyperactivity disorder (ADHD) using network analyses. Symptom network based on 18 items of ADHD Rating Scale-IV was evaluated in 4,033 children and adolescents with ADHD. The importance of nodes was evaluated quantitatively by examining centrality indices, including Strength, Betweenness and Closeness, as well as Predictability and Expected Influence (EI). In addition, we compared the network structure across different subgroups, as characterized by ADHD subtypes, gender and age groups to evaluate its invariance. A three-factor-community structure was identified including inattentive, hyperactive and impulsive clusters. For the centrality indices, the nodes of "Distracted" and "Fidget" showed high closeness and betweenness, and represented a bridge linking the inattentive and hyperactive/impulsive domains. "Details" and "Fidget" were the most common endorsed symptoms in inattentive and hyperactive/impulsive domains respectively. On the contrary, the "Listen" item formed a peripheral node showing weak links with all other items within the inattentive cluster, and the "Loss" item as the least central node by all measures of centrality and with low predictability value. The network structure was relatively invariant across gender, age and ADHD subtypes/presentations. The 18 items of ADHD core symptoms appear not equivalent and interchangeable. "Distracted" and "Fidget" should be considered as central, or core, symptoms for further evaluation and intervention. The network-informed differentiation of these symptoms has the potentials to refine the phenotype and reduce heterogeneity.

Effects of an intensive slow cortical potentials neurofeedback training in female and male adolescents with autism spectrum disorder : Are there sex differences?

Background

This study aims to compare the effects of neurofeedback training on male and female adolescents with autism spectrum disorder (ASD). Furthermore, it examines sex differences regarding improvements in co-occurring psychopathological symptoms, cognitive flexibility and emotion recognition abilities. The study might provide first hints whether there is an influence of sex on treatment outcomes.

Methods

Six female and six male adolescents with ASD were matched according to age, IQ and symptom severity. All participants received 24 sessions of electroencephalography-based neurofeedback training. Before and after the intervention, psychological data for measuring co-occurring psychopathological symptoms as well as behavioral data for measuring cognitive flexibility and emotion recognition abilities were recorded.

Results

Caregivers rated statistically significant higher psychopathological problems in female than in male adolescents with ASD at baseline. Apart from that, no statistically significant sex-related differences were revealed in this sample; however, male adolescents tended to report greater improvements of externalizing, internalizing and total symptoms, whereas females experienced smaller improvements of externalizing and total problems, but no improvements of internalizing problems. Regarding caregivers’ assessments, more improvement of total problems was reported for females. For males, only improvements of internalizing and total problems were described.

Conclusion

This study reveals preliminary results that sex-related differences might play a role when evaluating treatment outcomes after neurofeedback training regarding comorbid psychopathological symptoms. Adolescents’ self-report and parental assessments, especially concerning psychopathological symptoms, should be combined and considered in future studies to help prevent sex bias in adolescents with ASD.