Annual Research Review: Perspectives on progress in ADHD science - from characterization to cause

The distribution of parent-reported attention-deficit/hyperactivity disorder and subclinical autistic traits in children with and without an ADHD diagnosis

Background

Autistic traits are often reported to be elevated in children diagnosed with attention-deficit/hyperactivity disorder (ADHD). However, the distribution of subclinical autistic traits in children with ADHD has not yet been established; knowing this may have important implications for diagnostic and intervention processes. The present study proposes a preliminary model of the distribution of parent-reported ADHD and subclinical autistic traits in two independent samples of Australian children with and without an ADHD diagnosis.

Methods

Factor mixture modelling was applied to Autism Quotient and Conners' Parent Rating Scale - Revised responses from parents of Australian children aged 6-15 years who participated in one of two independent studies.

Results

A 2-factor, 2-class factor mixture model with class varying factor variances and intercepts demonstrated the best fit to the data in both discovery and replication samples. The factors corresponded to the latent constructs of 'autism' and 'ADHD', respectively. Class 1 was characterised by low levels of both ADHD and autistic traits. Class 2 was characterised by high levels of ADHD traits and low-to-moderate levels of autistic traits. The classes were largely separated along diagnostic boundaries. The largest effect size for differences between classes on the Autism Quotient was on the Social Communication subscale.

Conclusions

Our findings support the conceptualisation of ADHD as a continuum, whilst confirming the utility of current categorical diagnostic criteria. Results suggest that subclinical autistic traits, particularly in the social communication domain, are unevenly distributed across children with clinically significant levels of ADHD traits. These traits might be profitably screened for in assessments of children with high ADHD symptoms and may also represent useful targets for intervention.

Family screening for neurodevelopmental problems and its associations with child cognitive function enable tailored treatment for childhood obesity

AIM

To identify neurodevelopmental disorders in children with obesity, and investigate associations to cognitive functions as well as parents' self-reported neurodevelopmental problems.

METHODS

Eighty children were included at two outpatient obesity clinics in Sweden 2018-2019. Of these, 50 children without previously diagnosed neurodevelopmental disorders were screened, and so were their parents. Children who screened positive for neurodevelopmental problems were referred to a specialised psychiatry unit for further diagnosis. Test results of cognitive functioning were compared with the norm and between study groups by neurodevelopmental diagnoses.

RESULTS

Of the screened families, 17/50 children were diagnosed by the psychiatric unit with attention deficit-hyperactivity disorder (ADHD) and 15/82 parents screened positive for neurodevelopmental problems. Having a mother who screened positive for neurodevelopmental problems was associated with child ADHD (p < 0.05). The children's full-scale intelligence quotient (92.86 ± 12.01, p < 0.001) and working memory index (90.62 ± 12.17, p < 0.001) were lower than the norm. Working memory index was lower in children with ADHD compared to without ADHD: 84.76 ± 9.58 versus 94.09 ± 12.29 (p ≤ 0.01). Executive constraints were associated with verbal deviances.

CONCLUSION

Increased awareness is needed about the overlap between neurodevelopmental problems and obesity in obesity clinics.

Current perspectives on perinatal mental health and neurobehavioral development: focus on regulation, coregulation and self-regulation

PURPOSE OF REVIEW

Perinatal mental health research provides an important perspective on neurobehavioral development. Here, we aim to review the association of maternal perinatal health with offspring neurodevelopment, providing an update on (self-)regulation problems, hypothesized mechanistic pathways, progress and challenges, and implications for mental health.

RECENT FINDINGS

(1) Meta-analyses confirm that maternal perinatal mental distress is associated with (self-)regulation problems which constitute cognitive, behavioral, and affective social-emotional problems, while exposure to positive parental mental health has a positive impact. However, effect sizes are small. (2) Hypothesized mechanistic pathways underlying this association are complex. Interactive and compensatory mechanisms across developmental time are neglected topics. (3) Progress has been made in multiexposure studies. However, challenges remain and these are shared by clinical, translational and public health sciences. (4) From a mental healthcare perspective, a multidisciplinary and system level approach employing developmentally-sensitive measures and timely treatment of (self-)regulation and coregulation problems in a dyadic caregiver-child and family level approach seems needed. The existing evidence-base is sparse.

SUMMARY

During the perinatal period, addressing vulnerable contexts and building resilient systems may promote neurobehavioral development. A pluralistic approach to research, taking a multidisciplinary approach to theoretical models and empirical investigation needs to be fostered.

Intergenerational transmission of ADHD behaviors: genetic and environmental pathways

BACKGROUND

We investigate if covariation between parental and child attention-deficit hyperactivity disorder (ADHD) behaviors can be explained by environmental and/or genetic transmission.

METHODS

We employed a large children-of-twins-and-siblings sample (N = 22 276 parents and 11 566 8-year-old children) of the Norwegian Mother, Father and Child Cohort Study. This enabled us to disentangle intergenerational influences via parental genes and parental behaviors (i.e. genetic and environmental transmission, respectively). Fathers reported on their own symptoms and mothers on their own and their child's symptoms.

RESULTS

Child ADHD behaviors correlated with their mother's (0.24) and father's (0.10) ADHD behaviors. These correlations were largely due to additive genetic transmission. Variation in children's ADHD behaviors was explained by genetic factors active in both generations (11%) and genetic factors specific to the children (46%), giving a total heritability of 57%. There were small effects of parental ADHD behaviors (2% environmental transmission) and gene-environment correlation (3%). The remaining variability in ADHD behaviors was due to individual-specific environmental factors.

CONCLUSIONS

The intergenerational resemblance of ADHD behaviors is primarily due to genetic transmission, with little evidence for parental ADHD behaviors causing children's ADHD behaviors. This contradicts theories proposing environmental explanations of intergenerational transmission of ADHD, such as parenting theories or psychological life-history theory.

Identifying Risk Factors for Attention-Deficit/Hyperactivity Disorder (ADHD): a Public Health Concern and Opportunity

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders with significant individual and societal negative impacts of the disorder continuing into adulthood (Danielson et al. in Journal of Clinical Child and Adolescent Psychology, in press; Landes and London in Journal of Attention Disorders 25:3-13, 2021). Genetic and environmental risk (e.g., modifiable exposures such as prenatal tobacco exposure and child maltreatment) for ADHD is likely multifactorial (Faraone et al. in Neuroscience & Biobehavioral Reviews 128:789-818, 2021). However, the evidence for potentially modifiable contextual risks is spread across studies with different methodologies and ADHD criteria limiting understanding of the relationship between early risk factors and later childhood ADHD. Using common methodology across six meta-analyses (Bitsko et al. in Prevention Science, 2022; Claussen et al. in Prevention Science 1-23, 2022; Dimitrov et al. in Prevention Science, 2023; Maher et al. in Prevention Science, 2023; Robinson, Bitsko et al. in Prevention Science, 2022; So et al. in Prevention Science, 2022) examining 59 risk factors for childhood ADHD, the papers in this special issue use a public health approach to address prior gaps in the literature. This introductory paper provides examples of comprehensive public health approaches focusing on policy, systems, and environmental changes across socio-ecological contexts to improve health and wellbeing through prevention, early intervention, and support across development using findings from these meta-analyses. Together, the findings from these studies and a commentary by an author independent from the risk studies have the potential to minimize risk conditions, prioritize prevention efforts, and improve the long-term health and wellbeing of children and adults with ADHD.

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.

Further validation of a new ADHD screening questionnaire measuring parents' explanations (time processing, cognition, and motivation) of inattention symptoms in their school-aged children

The triple pathway model suggests that different neuropsychological factors underlie symptoms of inattention (i.e., time, cognition and/or motivation problems). However, screening instruments asking individuals to judge the link between these neuropsychological factors and inattention are lacking. The recently developed screening questionnaire, PASSC, aims to examine these factors possibly causing inattention by asking parents to indicate to what extent their child experiences inattention symptoms and to what extent different neuropsychological factors explain this inattention. The present study extends prior validation research of the PASSC by examining associations between PASSC inattention explained by time, cognition, and/or motivation and children's performance on tests measuring these same three constructs. Results indicated positive correlations between PASSC inattention explained by time and less accurate performance on a time discrimination test, and between PASSC inattention explained by cognition and more working memory errors as well as higher attention switching costs. Furthermore, children whose parents indicated that their inattention was best explained by cognition showed higher switching costs than children whose inattention was best explained by motivation. This support for construct validity of the PASSC is limited to two PASSC explanations (i.e., time, cognition) and a subset of tests (i.e., time discrimination, attention switching, memory span). Future research should focus on integrating PASSC and performance test results to differentiate between children with attention problems but different underlying neuropsychological problems. Concluding, the PASSC can be a promising screening tool to identify inattention in children and the underlying explanation indicated by parents.

Is Attention-Deficit/Hyperactivity Disorder (ADHD) a Dimension or a Category? What Does the Relationship Between ADHD Traits and Psychosocial Quality of Life Tell Us?

OBJECTIVE

The question of whether attention-deficit/hyperactivity disorder (ADHD) is a discrete category or a continuous dimension remains clinically relevant. We report the first examination of this question from the viewpoint of the relationship between ADHD traits and psychosocial quality of life (QoL), and whether the level of QoL declines markedly around a certain high ADHD trait range suggestive of a categorical boundary.

METHODS

Parents/caregivers of 1,967 schoolchildren aged 6 to 11 from the general population completed the Pediatric Quality of Life Inventory and the ADHD-Rating Scale IV. Piecewise linear and non-linear regression analyses were performed.

RESULTS

No evidence for a non-linear association or an abrupt change in the rate of decrease in QoL was observed in the high end of the ADHD traits continuum. Instead, the relationship was consistent with linearity.

CONCLUSION

Psychosocial QoL gradually declines in a linear manner as ADHD trait levels increase providing further support for a dimensional model.

Impulsivity profiles across five harmonized longitudinal childhood preventive interventions and associations with adult outcomes

This study aimed to parse between-person heterogeneity in growth of impulsivity across childhood and adolescence among participants enrolled in five childhood preventive intervention trials targeting conduct problems. In addition, we aimed to test profile membership in relation to adult psychopathologies. Measurement items representing impulsive behavior across grades 2, 4, 5, 7, 8, and 10, and aggression, substance use, suicidal ideation/attempts, and anxiety/depression in adulthood were integrated from the five trials (N = 4,975). We applied latent class growth analysis to this sample, as well as samples separated into nonintervention (n = 2,492) and intervention (n = 2,483) participants. Across all samples, profiles were characterized by high, moderate, low, and low-increasing impulsive levels. Regarding adult outcomes, in all samples, the high, moderate, and low profiles endorsed greater levels of aggression compared to the low-increasing profile. There were nuanced differences across samples and profiles on suicidal ideation/attempts and anxiety/depression. Across samples, there were no significant differences between profiles on substance use. Overall, our study helps to inform understanding of the developmental course and prognosis of impulsivity, as well as adding to collaborative efforts linking data across multiple studies to better inform understanding of developmental processes.

Neurophysiological Patterns of Attention and Distraction during Realistic Virtual-Reality Classroom Learning in Adults with and without ADHD

Many people, and particularly those diagnosed with ADHD, report difficulties maintaining attention and proneness to distraction during classroom learning. However, the behavioral, neural and physiological basis of attention in realistic learning contexts is not well understood, since current clinical and scientific tools used for evaluating and quantifying the constructs of "distractibility" and "inattention", are removed from the real-life experience in organic classrooms. Here we introduce a novel Virtual Reality (VR) platform for studying students' brain activity and physiological responses as they immerse in realistic frontal classroom learning. Using this approach, we studied whether adults with and without ADHD (N=49) exhibit differences in neurophysiological metrics associated with sustained attention, such as speech-tracking of the teacher's voice, power of alpha-oscillations and levels of arousal, as well as responses to potential disturbances by background sound-events in the classroom. Under these ecological conditions, we find that adults with ADHD exhibit higher auditory neural response to background sounds relative to their control-peers, which also contributed to explaining variance in the severity of ADHD symptoms, together with higher power of alpha-oscillations and more frequent gaze-shifts around the classroom. These results are in-line with higher sensitivity to irrelevant stimuli in the environment and increased mind-wandering/boredom. At the same time, both groups exhibited similar learning outcomes and showed similar neural tracking of the teacher's speech. This suggests that in this context, attention may not operate as a zero-sum game and that allocating some resources to irrelevant stimuli does not always detract from performing the task at hand. Given the dire need for more objective, dimensional and ecologically-valid measures of attention and its real-life deficits, this work provides new insights into the neurophysiological manifestations of attention and distraction experienced in real-life contexts, while challenging some prevalent notions regarding the nature of attentional challenges experienced by those with ADHD.

Participatory translational science of neurodivergence: model for attention-deficit/hyperactivity disorder and autism research

BACKGROUND

There are increasing calls for neurodivergent peoples' involvement in research into neurodevelopmental conditions. So far, however, this has tended to be achieved only through membership of external patient and public involvement (PPI) panels. The Regulating Emotions - Strengthening Adolescent Resilience (RE-STAR) programme is building a new participatory model of translational research that places young people with diagnoses of attention-deficit hyperactivity disorder (ADHD) and autism at the heart of the research team so that they can contribute to shaping and delivering its research plan.

AIMS

To outline the principles on which the RE-STAR participatory model is based and describe its practical implementation and benefits, especially concerning the central role of members of the Youth Researcher Panel (Y-RPers).

METHOD

The model presented is a culmination of a 24-month process during which Y-RPers moved from advisors to co-researchers integrated within RE-STAR. It is shaped by the principles of co-intentionality. The account here was agreed following multiple iterative cycles of collaborative discussion between academic researchers, Y-RPers and other stakeholders.

RESULTS

Based on our collective reflections we offer general guidance on how to effectively integrate young people with diagnoses of ADHD and/or autism into the core of the translational research process. We also describe the specific theoretical, methodological and analytical benefits of Y-RPer involvement in RE-STAR.

CONCLUSIONS

Although in its infancy, RE-STAR has demonstrated the model's potential to enrich translational science in a way that can change our understanding of the relationship between autism, ADHD and mental health. When appropriately adapted we believe the model can be applied to other types of neurodivergence and/or mental health conditions.

Development of a Short Version of the ADHD Rating Scale-IV.es (sADHD-RS-IV.es)

OBJECTIVE

To develop a short version of the Spanish 18-item ADHD-Rating Scale IV.es (sADHD-RS-IV.es) to be used as a potential screening tool in pediatric population.

METHODS

We recruited 652 subjects, ages 6 to 18 (mean ± SD = 11.14 ± 3.27): 518 patients with ADHD (per DSM-IV criteria); and 134 healthy controls. We performed a stepwise logistic regression to select the best subset of ADHD-RS-IV.es items to create a short-form. We calculated internal consistency reliability (Cronbach's and ordinal alphas) and diagnostic accuracy using receiver operating characteristic (ROC) curve.

RESULTS

Six items were found to enter the stepwise analysis significantly. Internal consistency was high (Cronbach's alpha = 0.86; ordinal alpha = 0.90) and offered a good concordance with clinician diagnosis and a high discriminatory power (AUC = 0.98) with an optimal cut-off at a score of six points.

CONCLUSIONS

This shorter questionnaire (six items) was able to discriminate ADHD cases from healthy controls.

Attention deficit and hyperactivity disorder and use of psychostimulants in Aotearoa, New Zealand: exploring the treatment gap

Introduction Attention deficit and hyperactivity disorder (ADHD) is a common neurodevelopmental disorder affecting about 7% of those aged up to 12 years, 5% of teenagers and 3% of adults. It is associated with poor academic performance, substance abuse, criminality, poor social functioning and other negative outcomes. Psychotherapeutic treatment is moderately successful, whereas pharmacotherapy with stimulant medication is more efficacious and is recommended in many international guidelines. Anecdotal evidence suggests underuse of these medications in Aotearoa, New Zealand. Aim To estimate how many patients with ADHD are prescribed psychostimulants in Aotearoa, New Zealand. Methods National prescribing data for dexamphetamine and methylphenidate in 2022 were obtained and matched against estimated prevalence of ADHD by age. Results There is a significant treatment gap for which inability to access first-line medication is likely to be the predominant explanation. Discussion The data suggest failure of our health system to provide reasonable health care for a significant number of people with ADHD, and results in inequity in outcomes. New approaches are needed that will increase access to first-line medication, yet maintain appropriateness of diagnosis and limit risk of medication diversion.

Personality Traits in Relation to Cognitive Disengagement Syndrome and ADHD Inattention in Two Samples of Children

OBJECTIVE

Cognitive disengagement syndrome (CDS; previously referred to as sluggish cognitive tempo) is a set of behaviors, including excessive mind-wandering, mental fogginess, and hypoactivity, that are separate from ADHD inattentive (ADHD-IN) symptoms and linked to functional outcomes. However, CDS and ADHD-IN symptoms are strongly associated, and our understanding of whether personality correlates are similarly or differentially linked to CDS and ADHD-IN is limited. The objective of the current study was to examine personality correlates of CDS and ADHD-IN symptoms across two independent samples of school-aged youth.

METHOD

Study 1 included 207 school-aged children (ages 7-11; 63% male; 87.9% White) with or without teacher-reported elevations in CDS. Study 2 included 263 school-aged children (ages 8-12; 58% male; 75.3% White) with the full range of CDS symptomatology. Parents and teachers completed ratings of ADHD-IN and CDS, and parents also reported on their child's personality dimensions.

RESULTS

Across two samples and controlling for demographic characteristics as well as ADHD-IN symptoms and other personality traits, higher levels of FFFS-fear/shyness were uniquely associated with higher levels of parent- and teacher-reported CDS symptoms. In most models, lower levels of BAS-drive were also uniquely associated with higher levels of CDS. In contrast, when controlling for demographic characteristics and CDS symptoms, higher levels of BAS-impulsivity/fun-seeking were uniquely associated with higher levels of parent- and teacher-reported ADHD-IN symptoms.

DISCUSSION

The findings provide the clearest evidence to date that personality dimensions are differentially associated with ADHD-IN and CDS symptoms in children, further underscoring CDS as a distinct construct from ADHD-IN.

Viloxazine Increases Extracellular Concentrations of Norepinephrine, Dopamine, and Serotonin in the Rat Prefrontal Cortex at Doses Relevant for the Treatment of Attention-Deficit/Hyperactivity Disorder

Background

Viloxazine ER (viloxazine extended-release capsules; Qelbree®), a nonstimulant attention-deficit/hyperactivity disorder (ADHD) treatment, has known activity as a norepinephrine (NE) transporter (NET) inhibitor. In vitro studies have also shown direct pharmacological effects on specific serotonin (5-HT) receptors, but not on the serotonin transporter (SERT). An in vivo microdialysis study in rats showed viloxazine (50 mg/kg i.p.) increased extracellular 5-HT, NE, and dopamine (DA) in the prefrontal cortex (PFC), a key brain region in ADHD pathology. This study evaluated whether these effects occur at clinically relevant concentrations.

Methods

Microdialysis experiments were conducted in freely-moving, Sprague-Dawley rats (males, 8 weeks). Viloxazine (1, 3, 10, 30 mg/kg) was administered intraperitoneally to establish the dose range in rats at which viloxazine plasma concentrations aligned with those of individuals with ADHD administered therapeutic doses of viloxazine ER. Concentrations of unbound viloxazine, NE, 5-HT, DA, and NE and 5-HT metabolites (3,5-dihydroxyphenylglycol [DHPG] and 5-hydroxyindoleacetic acid [5-HIAA]) were measured in PFC interstitial fluid. After identifying a therapeutically relevant dose (30 mg/kg), the experiment was repeated using 30 and 50 mg/kg viloxazine (as 50 mg/kg increased NE, 5-HT, and DA in prior studies).

Results

Viloxazine unbound (free drug) plasma concentrations in rats at 30 mg/kg were comparable to free drug concentrations in individuals with ADHD taking clinically effective doses (based on validated population PK models). Viloxazine 30 mg/kg significantly increased extracellular NE, 5-HT, and DA PFC levels compared to vehicle. Concomitant decreases in DHPG, but not 5-HIAA, support the inhibitory effect of viloxazine on NET but not SERT.

Conclusion

At clinically relevant concentrations, viloxazine increases PFC NE, DA, and 5-HT. Prefrontal augmentation of 5-HT does not appear to result from 5-HT reuptake inhibition but may be related to activation of 5-HT neurons. The potential therapeutic role of serotonergic effects in ADHD treatment merits further exploration.

Perspectives on ADHD in children and adolescents as a social construct amidst rising prevalence of diagnosis and medication use

The diagnosis of attention-deficit hyperactivity disorder (ADHD) is based on the presence of pervasive, persistent symptoms of inattention and/or hyperactivity/impulsivity typically emerging early in life and resulting in significant functional impairment. In contrast to a worldwide epidemiological prevalence of approximately 5% in children and 2-3% in adults, there are significant variations in the prevalence of administrative ADHD diagnoses and medication use. We assert that in order to explore the underlying dynamics of this phenomenon, a thorough understanding of the construct ADHD is necessary. We contend that ADHD is not a natural entity that unfolds within an individual and can be understood independent from societal and environmental factors, but rather that ADHD as a diagnosis can better be conceptualized as a valid and pragmatically useful social construct. Decisions to diagnose and treat ADHD should follow a person-centered approach and be focused on functional impairment within a socially constructed, context-dependent and environmentally contingent model.

Parental Report of Remission in ADHD: Results From a Community-Based, Nationally Representative Sample

OBJECTIVE

Various studies have examined rates of remission in ADHD with mixed results.

METHOD

Survival curve analyses were performed on a community-based sample.

RESULTS

The results of the current study appear to support the contemporary literature that rates of remission in ADHD are lower than have been found in many earlier studies. The current study also reports a mean age of remission in ADHD of around 14 years old, which has not been previously reported via survival curve analyses. Additionally, the results of the current study found several variables to be significantly associated with remission in ADHD which included: the presence of comorbid disorder; lower symptoms of ADHD; sex of the child (being female); and the receipt of behavioral treatment.

CONCLUSION

Implications and limitations are discussed as related to these findings.

Stories of Hope: Young People's Personal Narratives About ADHD Put Into Context of Positive Aspects

There is a growing acceptance that ADHD is a multi-dimensional disorder in which not all symptoms are associated with deficits or functional impairments. This article contributes to research on the positive aspects of the diagnosis, specifically understanding the positive aspects of living with ADHD. The empirical data was based on individual interviews and self-narratives of 10 young adults with ADHD. Narrative analysis was implemented when investigating their stories. The findings showed that challenges with the diagnosis were not necessarily stably occupied, and for some, the diagnosis was thought of as a benefit and something they would not have been without. Four stories highlighted particularly the context of positive aspects: (1) insight and strategies, (2) targeted efforts, (3) balanced energy, and (4) social skills. These aspects were correlated to both the individual's strengths as well as the strengths and support that could be related to their societal and cultural environment.

Diffusion kurtosis imaging reveals abnormal gray matter and white matter development in some brain regions of children with attention-deficit/hyperactivity disorder

In this study, we explored the application of diffusion kurtosis imaging (DKI) technology in the brains of children with attention-deficit/hyperactivity disorder (ADHD). Seventy-two children with ADHD and 79 age- and sex-matched healthy controls were included in the study. All children were examined by means of 3D T1-weighted image, DKI, and conventional sequence scanning. The volume and DKI parameters of each brain region were obtained by software postprocessing (GE ADW 4.6 workstation) and compared between the two groups of children to determine the imaging characteristics of children with ADHD. The result showed the total brain volume was lower in children with ADHD than in healthy children (p < .05). The gray and white matter volumes in the frontal lobe, temporal lobe, hippocampus, caudate nucleus, putamen, globus pallidus, and other brain regions were lower in children with ADHD than in healthy children (p < .05). The axial kurtosis (Ka), mean kurtosis (MK), fractional anisotropy (FA), and radial kurtosis(Kr) values in the frontal lobe, temporal lobe, and caudate nucleus of children with ADHD were lower than those of healthy children, while the mean diffusivity(MD) and fractional anisotropy of kurtosis (FAK) values were higher than those of healthy children (p < .05). Additionally, the Ka, MK, FA, and Kr values in the frontal lobe, caudate nucleus, and temporal lobe could be used to distinguish children with ADHD (AUC > .05, p < .05). In conclusion, DKI showed abnormal gray matter and white matter development in some brain regions of children with ADHD.

Differential neurocognitive profiles in adult attention-deficit/hyperactivity disorder subtypes revealed by the Cambridge Neuropsychological Test Automated Battery

Adult attention-deficit/hyperactivity disorder (aADHD) represents a heterogeneous entity incorporating different subgroups in terms of symptomatology, course, and neurocognition. Although neurocognitive dysfunction is generally associated with aADHD, its severity, association with self-reported symptoms, and differences between subtypes remain unclear. We investigated 61 outpatients (65.6% male, mean age 31.5 ± 9.5) diagnosed using DSM-5 criteria together with age-, sex-, and education-matched healthy controls (HC) (n = 58, 63.8% male, mean age 32.3 ± 9.6). Neurocognitive alterations were assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB) and compared between groups using the generalized linear model (GLM) method. Multivariate effects were tested by principal component analysis combined with multivariate pattern analysis. Self-reported symptom severity was tested for correlations with neurocognitive performance. GLM analyses revealed nominally significant differences between the aADHD and HC groups in several domains, however, only the Rapid Visual Information Processing measures survived correction, indicating impaired sustained attention and response inhibition in the aADHD group. Comparison of the predominantly inattentive and the hyperactive-impulsive/combined subtypes yielded nominally significant differences with higher levels of dysfunction in the inattentive group. In the stepwise discriminant analysis aADHD and HC groups were best separated with 2 factors representing sustained attention and reaction time. We found only weak correlations between symptom severity and CANTAB factors. aADHD patients are neuropsychologically heterogeneous and subtypes show different neurocognitive profiles. Differences between the aADHD and HC groups were driven primarily by the inattentive subtype. Sustained attention and its factor derivative showed the most significant alterations in aADHD patients.

Screening for Attention Deficit Hyperactivity Disorder in Young Autistic Adults: The Diagnostic Accuracy of Three Commonly Used Questionnaires

OBJECTIVE

Attention Deficit Hyperactivity Disorder (ADHD) is a common co-occurring condition in autistic individuals. ADHD is sometimes first recognised in young adulthood because ADHD symptoms may be misattributed to autism due to superficial overlap in presentation and diagnostic overshadowing. It should be investigated whether ADHD questionnaires are accurate in screening symptoms in young adults with autism. The current study examined this.

METHODS

Participants were autistic young adults (N = 119) who took part in the Special Needs and Autism Project (SNAP), a population-based cohort. ADHD research diagnoses were obtained through the parent-informed Young Adult Psychiatric Assessment. Parents and young adults (self-report sample N = 71) completed ADHD questionnaires (Aberrant Behavior Checklist hyperactivity/non-compliance subscale, Conners Adult ADHD Rating Scales ADHD Index, and Strengths and Difficulties Questionnaire ADHD subscale). Receiver operating characteristic analyses were conducted to explore if the questionnaires discriminated ADHD cases from non-cases. To assess whether results varied by intellectual functioning, subgroup analyses were completed for those with an IQ ≥ 70 vs. <70.

RESULTS

Weighted ADHD rates were high. Overall although the measures were performing at or close to adequate levels (area under the curve was 0.66 to 0.79 for parent-report and 0.70 to 0.65 for self-report), no single measure met adequate thresholds for sensitivity and specificity simultaneously. Tool performance was not different for those with an IQ ≥ 70 vs. <70.

CONCLUSION

No single measure reported adequate performance for distinguishing ADHD from non-ADHD cases in this sample of young autistic adults. Use of current thresholds may lead to under-diagnosis.

Exploring Teachers' Knowledge and Attitudes Toward Attention Deficit Hyperactivity Disorder and Its Treatment in a District of Turkey

Background Teachers are pivotal in integrating children with attention deficit hyperactivity disorder (ADHD) into academic and social contexts. Their comprehension of and attitudes toward ADHD significantly influence the inclusion of these children. This study was conducted to assess teachers' knowledge, attitudes, and perceptions about ADHD and its treatment within a representative sample from Turkey. Methods An online self-administered questionnaire was formulated to gauge teachers' knowledge, attitudes, and perceptions related to ADHD and its treatment. Results Of the respondents, 57.7% accurately identified that ADHD is more commonly present in boys. Furthermore, a majority of teachers (60.8%) correctly answered the question related to the comorbidity of ADHD and learning disabilities. However, 20.3% of teachers believed that ADHD medications were addictive, with 9.7% expressing reluctance to use such treatment for their children if needed. Conclusion The results highlight the need for revising the current training curricula for novice teachers and providing additional training for experienced teachers. Such initiatives should aim to rectify any negative perceptions and attitudes toward ADHD held by teachers.

Editorial: Unsettling 'settled' science - the importance of questioning received wisdom about the causes of mental health and neuro-developmental conditions

The papers included in this year's Annual Research Review represent a heterogenous mix of concerns, zooming out, in some cases, to summarize the state of the science for a particular condition or developmental process and zooming in, in other cases, to identify effects of specific (and timely) risk factors for child and adolescent mental health. These papers highlight where the field has made significant strides in advancing our understanding of etiology or mechanisms of change or stability and they highlight how much is left to learn about the causes of psychopathology and the conditions under which developmental trajectories are maintained or disrupted.

A preliminary study of white matter correlates of a laboratory measure of attention and motor stability in attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is a complex behavioral disorder, often difficult and time consuming to diagnose. Laboratory assessment of ADHD-related constructs of attention and motor activity may be helpful in elucidating neurobiology; however, neuroimaging studies evaluating laboratory measures of ADHD are lacking. In this preliminary study, we assessed the association between fractional anisotropy (FA), a measure of white matter microstructure, and laboratory measures of attention and motor behavior using the QbTest, a widely used measure thought to improve clinician diagnostic confidence. This is the first look at neural correlates of this widely used measure. The sample included adolescents and young adults (ages 12-20, 35% female) with ADHD (n = 31) and without (n = 52). As expected, ADHD status was associated with motor activity, and cognitive inattention and impulsivity in the laboratory. With regard to MRI findings, laboratory observed motor activity and inattention were associated with greater FA in white matter regions of the primary motor cortex. All three laboratory observations were associated with lower FA in regions subserving fronto-striatal-thalamic and frontoparietal (i.e. superior longitudinal fasciculus) circuitry. Further, FA in white matter regions of the prefrontal cortex appeared to mediate the relationship between ADHD status and motor activity on the QbTest. These findings, while preliminary, suggest that performance on certain laboratory tasks is informative with regard to neurobiological correlates of subdomains of the complex ADHD phenotype. In particular, we provide novel evidence for a relationship between an objective measure of motor hyperactivity and white matter microstructure in motor and attentional networks.

Taking stock of the present and looking to the future of ADHD research: a commentary on Sonuga-Barke et al. (2023)

The review by Sonuga-Barke and colleagues offers a thoughtful and wide-ranging appraisal of the current state of ADHD research, while also looking into the future to consider unresolved questions and critical next steps. Furthermore, it grapples with the tension between the need to define a coherent conceptualisation of ADHD for clinical and research purposes, while keeping an open mind to new research that challenges current consensus. In our commentary, we consider several cross-cutting ideas discussed in Sonuga-Barke et al., including the heterogeneous nature of ADHD, ensuring equity of translational research, and the importance of participatory research to support equitable and acceptable clinical practices for all individuals with ADHD.

Immersive virtual reality for improving cognitive deficits in children with ADHD: a systematic review and meta-analysis

Virtual reality (VR) shows great potential in treating and managing various mental health conditions. This includes using VR for training or rehabilitation purposes. For example, VR is being used to improve cognitive functioning (e.g. attention) among children with attention/deficit-hyperactivity disorder (ADHD). The aim of the current review and meta-analysis is to evaluate the effectiveness of immersive VR-based interventions for improving cognitive deficits in children with ADHD, to investigate potential moderators of the effect size and assess treatment adherence and safety. The meta-analysis included seven randomised controlled trials (RCTs) of children with ADHD comparing immersive VR-based interventions with controls (e.g. waiting list, medication, psychotherapy, cognitive training, neurofeedback and hemoencephalographic biofeedback) on measures of cognition. Results indicated large effect sizes in favour of VR-based interventions on outcomes of global cognitive functioning, attention, and memory. Neither intervention length nor participant age moderated the effect size of global cognitive functioning. Control group type (active vs passive control group), ADHD diagnostic status (formal vs. informal) and novelty of VR technology were not significant moderators of the effect size of global cognitive functioning. Treatment adherence was similar across groups and there were no adverse effects. Results should be cautiously interpreted given the poor quality of included studies and small sample.

Editorial: 'Safety in numbers'? Big data discovery strategies in neuro-developmental science - contributions and caveats

In the last 10 years, we have seen a shift toward the use of big data hypothesis-free discovery strategies in studies of neuro-development and mental health. In this editorial, I discuss the reasons for their popularity, their potential contribution as well as some limitations and pitfalls. I conclude with a call for methodological pluralism where big data approaches are strategically integrated into cycles of hypothesis generation and testing.