A comprehensive investigation of memory impairment in attention deficit hyperactivity disorder and oppositional defiant disorder

Enhancing spatial memory and pattern separation: Long-term effects of stimulant treatment in individuals with ADHD

This study explores the under-researched domain of long-term stimulant treatment in children and adolescents diagnosed with attention deficit hyperactivity disorder (ADHD). The necessity for extended treatment duration, often accompanied by safety concerns and side effects leading to treatment discontinuation, underscores the significance of this investigation. Concurrently, comparative studies have revealed adverse impacts on vulnerable regions within the hippocampal formation, accompanied by behavioral perturbations. We employed computerized tests and virtual reality to assess spatial memory, pattern separation, and object recognition memory in a cohort of children diagnosed with ADHD receiving stimulant treatment. We compared their performance to a group of neurotypical peers. Our findings indicate that the ADHD group exhibited a lower performance in spatial memory, pattern separation, and object recognition memory than ND group. Intriguingly, a positive relationship emerged between the duration of stimulant treatment and performance in these variables. Notably, this improvement was not immediate to MPH treatment but becomes significant after 24 months of treatment. In contrast to previous comparative investigations, our study did not reveal a detrimental impact on spatial navigation, object recognition memory, or pattern separation, despite the known interplay of these cognitive processes with the hippocampal formation. These results shed new light on the nuanced effects of stimulant treatment in ADHD, underscoring the need for a more comprehensive understanding of long-term treatment outcomes.

Development of EEG alpha and theta oscillations in the maintenance stage of working memory

Several studies have shown developmental changes in EEG oscillations during working memory tasks. Although the load-modulated theta and alpha activities in adults are well-documented, the findings are inconsistent if children possess the adult-like brain oscillations that are similarly modulated by memory load. The present study compares children's and adults' true theta and alpha EEG oscillations, separated from aperiodic components, in the maintenance stage of working memory. The EEG was recorded in 25 Chinese-speaking children (14 male, Mage = 9.4 yrs) and 31 adults (19 male, Mage = 20.8 yrs) in Hong Kong while they performed an n-back task that included four conditions differing in load (1- vs. 2-back) and stimulus type (Chinese character vs. visual pattern). The results show that aperiodic activities (i.e., broadband power and slope) during the maintenance stage in the n-back task were significantly higher in children than adults. The periodic theta and alpha oscillations also changed with age. More importantly, adults showed significant periodic theta increase with memory load, whereas such an effect was absent in children. Regardless of age, there was a significant alpha power decrease with load increase, and a significant theta power enhancement when maintaining visual patterns than Chinese characters. In adults, load-modulated alpha peak shift (towards higher frequency) was linked to higher behavioral efficiency in the n-back task. In children, higher load-modulated theta enhancement was linked to better behavioral efficiency. The findings suggest that the load-modulated theta power during working memory maintenance matures from childhood to adulthood.

Co-production of the 'EPIC' multidimensional tool-kit to support neurodivergent children and young people at home and school: a feasibility and pilot study

BACKGROUND

Interventions focused on cognitive function in neurodivergent children typically focus on single functions, e.g. working memory training. They are often focused on 'deficit' models and lack an emphasis on understanding areas of individual strengths and difficulties as a prerequisite to appropriate support. The multidimensional nature and phenotypic variability of cognitive profiles in these children indicate a need for a multicomponent-tailored intervention programme focused on understanding and supporting an individual child's cognitive functioning.

AIMS

The 'EPIC' intervention (Edinburgh Psychoeducation Intervention for Children and Young People) is focused on improving cognition, learning and behaviour in neurodivergent children such as those with attention deficit hyperactivity disorder (ADHD) or who are autistic. Building on our previous co-production work, this study aimed to use a participatory methods approach to develop EPIC practices and materials in relation to our key principles which include psychoeducation, multicomponent, individualised approach, strengths and difficulties profiling and pairing of a child's individual strengths and difficulties with internal and external strategies. We also set out to assess the feasibility and acceptability of EPIC, and pilot this novel tool-kit intervention with neurodivergent children and their parents and teachers.

METHODS

The intervention practices, materials and strategies of EPIC were co-produced with neurodivergent children, their parents, teachers and clinicians taking a strengths and difficulties approach. Identification of psychoeducation activities and strategy practices (e.g. mind-maps, chunking), testing of feasibility and collection of pilot data were conducted over a bi-weekly 8-week programme. Eleven neurodivergent children aged 7 to 12 completed the 16-session individualised programme. Acceptability and feasibility were ascertained via qualitative reports elicited within child and teacher interviews and child ratings of enjoyment. Pilot evaluation data was collected pre- and post-intervention participation, and across cognitive assessments (CANTAB, BRIEF), educational attainment (WIAT) and parent and teacher questionnaires measuring clinical symptoms and behaviour (Conners, AQ, SDQ, self-perception). Data was compared with a matched neurodivergent treatment-as-usual control group (N = 9).

RESULTS

The co-produced EPIC intervention was both feasible to deliver and acceptable to children, parents and their teachers. Pilot data identified that the 8-week intervention improved cognition (short-term and working memory) and literacy (receptive vocabulary, oral word fluency, listening comprehension). Improvements in the intervention group were also found for parent-reported child behavioural difficulties and aggression, and teacher-reported scholastic competence. Effect sizes generated (Cohen's d) ranged from 0.65 to 2.83. Parents reported continuing to use EPIC strategies when interviewed over a year after participating in the programme.

CONCLUSION

The current study met our objectives fully. 'EPIC' (Edinburgh Psychoeducation Intervention for Children and Young People) is feasible in home and school contexts and improves a range of aspects of cognition, learning and behaviour in neurodivergent children. Our findings show EPIC is suitable to be assessed within a full-scale trial.

Predictive associations of executive functions and oppositional defiant problems and obsessive-compulsive problems in preschoolers

Oppositional defiant problems (ODP) and obsessive-compulsive problems (OCP) may co-occur in children, though the way they interact is not known. The aim of the study was to examine longitudinal associations between executive functions at age 3 and ODP, ODP dimensions, and OCP at age 6. The sample consisted of 622 preschoolers (50% were boys) from the general population. Executive functions were assessed by teachers using the Behavior Rating Inventory of Executive Functioning - Preschool version questionnaire when children were 3 years old, and ODP and OCP were informed by parents and teachers at the age of 6 years. Multiple linear regression analyses indicated that higher Inhibit and Emotional Control and lower Shift deficits were associated with higher ODP reported by teachers, while higher Shift but lower Inhibit deficits were related to higher OCP. Moreover, ODP and OCP shared difficulties on the Flexibility Index, which means that the capacity to modulate emotions and behavior according to contextual and environmental demands is compromised in both disorders. The findings inform etiology and prevention, pointing out not only the executive function specificities related to each problem, but also common cognitive challenges related to Flexibility. Young children could benefit from training and programs designed to improve executive function processes at an early age to prevent later behavioral difficulties.

Object Recognition Memory Deficits in ADHD: A Meta-analysis

Object recognition memory allows us to identify previously seen objects. This type of declarative memory is a primary process for learning. Despite its crucial role in everyday life, object recognition has received far less attention in ADHD research compared to verbal recognition memory. In addition to the existence of a small number of published studies, the results have been inconsistent, possibly due to the diversity of tasks used to assess recognition memory. In the present meta-analysis, we have collected studies from Web of Science, Scopus, PubMed, and Google Scholar databases up to May 2023. We have compiled studies that assessed visual object recognition memory with specific visual recognition tests (sample-match delayed tasks) in children and adolescents diagnosed with ADHD. A total of 28 studies with 1619 participants diagnosed with ADHD were included. The studies were assessed for risk of bias using the Quadas-2 tool and for each study, Cohen's d was calculated to estimate the magnitude of the difference in performance between groups. As a main result, we have found a worse recognition memory performance in ADHD participants when compared to their matched controls (overall Cohen's d ~ 0.492). We also observed greater heterogeneity in the magnitude of this deficit among medicated participants compared to non-medicated individuals, as well as a smaller deficit in studies with a higher proportion of female participants. The magnitude of the object recognition memory impairment in ADHD also seems to depend on the assessment method used.

Executive functioning in antisocial behavior: A multi-level systematic meta-analysis

Neurobiological information - including executive functioning - is increasingly relevant for forensic clinical practice, as well as for the criminal justice system. Previous meta-analyses report that antisocial populations show impaired performance on executive functioning tasks, but these meta-analyses are outdated, have limitations in their methodological approach, and are therefore in need of an update. The current multi-level meta-analysis including 133 studies (2008-2023) confirms impaired performance in executive functioning (d=.42), but studies are heterogeneous. Several moderator analyses showed that neuropsychological test used, type of executive function component, and control group characteristics moderated the overall effect. Specifically, matching psychiatric problems in the non-antisocial control group eliminated any differences in executive functioning between groups. No moderation effects were found for assessment quality, hot or cold executive functions, and various population characteristics. These results could indicate that the assessment of executive functioning in antisocial populations may be less relevant for recidivism risk assessment than thought, although this should first be assessed in prospective longitudinal studies. Executive functioning could potentially be used to identify or screen for individuals with certain treatment needs or be used as a responsivity factor, especially in disorders which are often underdiagnosed in criminal justice settings.

Understanding and Supporting Attention Deficit Hyperactivity Disorder (ADHD) in the Primary School Classroom: Perspectives of Children with ADHD and their Teachers

Children with Attention Deficit Hyperactivity Disorder (ADHD) are more at risk for academic underachievement compared to their typically developing peers. Understanding their greatest strengths and challenges at school, and how these can be supported, is vital in order to develop focused classroom interventions. Ten primary school pupils with ADHD (aged 6-11 years) and their teachers (N = 6) took part in semi-structured interviews that focused on (1) ADHD knowledge, (2) the child's strengths and challenges at school, and (3) strategies in place to support challenges. Thematic analysis was used to analyse the interview transcripts and three key themes were identified; classroom-general versus individual-specific strategies, heterogeneity of strategies, and the role of peers. Implications relating to educational practice and future research are discussed.

High-fat diet-induced dopaminergic dysregulation induces REM sleep fragmentation and ADHD-like behaviors

Consumption of a high-fat diet (HFD) has been associated with reduced wakefulness and various behavioral deficits, including anxiety, depression, and anhedonia. The dopaminergic system, which plays a crucial role in sleep and ADHD, is known to be vulnerable to chronic HFD. However, the association between HFD-induced behavioral and molecular changes remains unclear. Therefore, we investigated the effects of a HFD on the dopaminergic system and its association with behavioral deficits in male mice. The mice were divided into normal diet and HFD groups and were analyzed for sleep patterns, behavior tests, and transcription levels of dopamine-related genes in the brain. The HFD group showed decreased wakefulness, increased REM sleep with fragmented patterns, decreased time spent in the center zone of the open field test, shorter immobile time in the tail suspension test, impaired visuospatial memory, and reduced sucrose preference. Additionally, the HFD group had decreased mRNA levels of D1R, COMT, and DAT in the nucleus accumbens, which negatively correlated with REM sleep proportion and REM sleep bout count. The results suggest that HFD-induced behavioral deficits were resemblance to ADHD-like behavioral phenotypes and disturbs REM sleep by dysregulating the dopaminergic system.

Child Developmental MRI (CDM) project: protocol for a multi-centre, cross-sectional study on elucidating the pathophysiology of attention-deficit/hyperactivity disorder and autism spectrum disorder through a multi-dimensional approach

INTRODUCTION

Neuroimaging studies on attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) have demonstrated differences in extensive brain structure, activity and network. However, there remains heterogeneity and inconsistency across these findings, presumably because of the diversity of the disorders themselves, small sample sizes, and site and parameter differences in MRI scanners, and their overall pathogenesis remains unclear. To address these gaps in the literature, we will apply the travelling-subject approach to correct site differences in MRI scanners and clarify brain structure and network characteristics of children with ADHD and ASD using large samples collected in a multi-centre collaboration. In addition, we will investigate the relationship between these characteristics and genetic, epigenetic, biochemical markers, and behavioural and psychological measures.

METHODS AND ANALYSIS

We will collect resting-state functional MRI (fMRI) and T1-weighted and diffusion-weighted MRI data from 15 healthy adults as travelling subjects and 300 children (ADHD, n=100; ASD, n=100; and typical development, n=100) with multi-dimensional assessments. We will also apply data from more than 1000 samples acquired in our previous neuroimaging studies on ADHD and ASD.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Research Ethics Committee of the University of Fukui Hospital (approval no: 20220601). Our study findings will be submitted to scientific peer-reviewed journals and conferences.

Cognition and maths in children with Attention-Deficit/Hyperactivity disorder with and without co-occurring movement difficulties

BACKGROUND

Movement difficulties are common in ADHD, however, the implications of their co-occurrences on cognitive and maths performance is unknown.

AIMS

This study set out to examine whether cognitive and maths performance of children with high ADHD symptoms differs depending on the co-occurrence of movement difficulties given evidence that weaker visuospatial processing, known to be important for maths performance, differentiates ADHD and DCD. We also aimed to examine whether relationships between cognition and maths in ADHD differs depending on co-occurring movement difficulties.

METHODS

Participants were 43 drug naïve children between 6 and 12 years old (M = 101.53 months SD = 19.58). The ADHD-only group (n = 18) included children with high ADHD scores, and those in the ADHD+DCD group (n = 25) concurrently had high movement difficulty scores. All completed executive function and memory, including 2 visuo-spatial memory tasks from the CANTAB battery and Mathematics Problem Solving, Numeracy, and Maths Fluency tasks from the WIAT-III and specific factual, conceptual, and procedural maths component tasks.

RESULTS

Children in the ADHD+DCD group scored significantly lower on visuospatial working memory (WM) capacity, than those in the ADHD-only group. Both groups were comparable on all other cognitive assessments of executive functions, memory, and processing speed. The groups did not differ in their maths attainment scores, nor on more specific maths skills. Comparison of the correlations between cognitive processes and maths revealed that the association between visuospatial WM updating and procedural skill efficiency was stronger for the ADHD-only group. Moreover, associations between visuospatial WM and maths problem solving attainment were stronger in the ADHD+DCD group.

CONCLUSIONS

Despite similarities in maths performance, children with ADHD+DCD could be distinguished by lower visuospatial WM. Differential associations with some of the maths domain implicate recruitment of different cognitive processes for some aspects of maths. This distinction can be particularly useful for conceptualising cognitive characteristics of different clinical groups and understanding cognitive pathways of maths difficulties. Implications for interventions are discussed.

The role of moment-to-moment dynamics of perceived stress and negative affect in co-occurring ADHD and internalising symptoms

A maladaptive response to stress in individuals with high ADHD traits may be a key factor explaining co-occurring ADHD symptoms and internalising problems. The current study investigates whether between-person differences in ADHD traits are associated with differences in the within-person moment-to-moment coupling of stress and negative affect; and whether these can explain between-person differences in internalising problems (N = 262, median-age 20). Results of a dynamic structural equation model indicated that between-person differences in ADHD traits significantly moderated the daily life coupling between stress and negative affect. Further, higher ADHD traits were associated with stronger stress carry-over and higher mean levels of negative affect. Stress carry-over and mean levels of negative affect mediated the association between ADHD traits and internalising problems.

Specific Learning Disabilities and Emotional-Behavioral Difficulties: Phenotypes and Role of the Cognitive Profile

Specific Learning Disabilities (SLD) are often associated with emotional-behavioral problems. Many studies highlighted a greater psychopathological risk in SLD, describing both internalizing and externalizing problems. The aims of this study were to investigate the emotional-behavioral phenotype through the Child Behavior Checklist (CBCL), and evaluate the mediating role of background and cognitive characteristics on the relationship between CBCL profile and learning impairment in children and adolescents with SLD. One hundred and twenty-one SLD subjects (7-18 years) were recruited. Cognitive and academic skills were assessed, and parents completed the questionnaire CBCL 6-18. The results showed that about half of the subjects manifested emotional-behavioral problems with a prevalence of internalizing symptoms, such as anxiety and depression, over externalizing ones. Older children showed greater internalizing problems than younger ones. Males have greater externalizing problems compared to females. A mediation model analysis revealed that learning impairment is directly predicted by age and familiarity for neurodevelopmental disorders and indirectly via the mediation of the WISC-IV/WAIS-IV Working Memory Index (WMI) by the CBCL Rule-Breaking Behavior scale. This study stresses the need to combine the learning and neuropsychological assessment with a psychopathological evaluation of children and adolescents with SLD and provides new interpretative insights on the complex interaction between cognitive, learning, and emotional-behavioral phenotypes.

Thrsp Gene and the ADHD Predominantly Inattentive Presentation

There are three presentations of attention-deficit/hyperactivity disorder (ADHD): the predominantly inattention (ADHD-PI), predominantly hyperactive-impulsive (ADHD-HI), and combined (ADHD-C) presentations of ADHD. These may represent distinct childhood-onset neurobehavioral disorders with separate etiologies. ADHD diagnoses are behaviorally based, so investigations into potential etiologies should be founded on behavior. Animal models of ADHD demonstrate face, predictive, and construct validity when they accurately reproduce elements of the symptoms, etiology, biochemistry, and disorder treatment. Spontaneously hypertensive rats (SHR/NCrl) fulfill many validation criteria and compare well with clinical cases of ADHD-C. Compounding the difficulty of selecting an ideal model to study specific presentations of ADHD is a simple fact that our knowledge regarding ADHD neurobiology is insufficient. Accordingly, the current review has explored a potential animal model for a specific presentation, ADHD-PI, with acceptable face, predictive, and construct validity. The Thrsp gene could be a biomarker for ADHD-PI presentation, and THRSP OE mice could represent an animal model for studying this distinct ADHD presentation.

Predictors and Moderators Two Treatments of Oppositional Defiant Disorder in Children

OBJECTIVE

The aim of this study was to examine predictors and moderators of behavioral improvement in children with Oppositional Defiant Disorder (ODD) following treatment with Parent Management Training (PMT) and Collaborative and Proactive Solutions (CPS). Initial problem severity, inconsistent discipline, parental attributions of child misbehavior, and child lagging cognitive skills were examined.

METHOD

One hundred and forty-five children aged between 7 and 14 (103 males, M = 8.88 years, ethnicity representative of the wider Australian population) were randomly assigned to PMT and CPS. Assessment was conducted at baseline, post-intervention, and at 6-month follow-up, using independently rated semi-structured diagnostic interviews and parent-ratings of ODD symptoms. Using an intent-to-treat sample in this secondary analysis (Murrihy et al., 2022), linear regressions and PROCESS (Hayes, 2017) were used to examine these predictors and possible moderators of treatment.

RESULTS

Higher pre-treatment levels of conduct problems, lagging skills, and inconsistent discipline predicted poorer behavioral outcomes following both treatments. The only characteristic that moderated treatment outcome was child-responsible attributions - mothers who were more likely to attribute their child's problematic behaviors to factors in the child had significantly poorer outcomes in PMT than CPS at 6-month follow-up.

CONCLUSIONS

CPS may be a more beneficial treatment than PMT for families who have been identified as having higher levels of child-responsible attributions before commencing treatment for ODD. While tentative, this provides promising insights as to how treatment outcomes for children with ODD may be improved.

Stimulant and non-stimulant drug therapy for people with attention deficit hyperactivity disorder and epilepsy

BACKGROUND

Attention Deficit Hyperactivity Disorder (ADHD) can co-occur in up to 40% of people with epilepsy. There is debate about the efficacy and tolerability of stimulant and non-stimulant drugs used to treat people with ADHD and co-occurring epilepsy.

OBJECTIVES

To assess the effect of stimulant and non-stimulant drugs on children and adults with ADHD and co-occurring epilepsy in terms of seizure frequency and drug withdrawal rates (primary objectives), as well as seizure severity, ADHD symptoms, cognitive state, general behaviour, quality of life, and adverse effects profile (secondary objectives).

SEARCH METHODS

We searched the following databases on 12 October 2020: Cochrane Register of Studies (CRS Web), MEDLINE (Ovid, 1946 to 9 October 2020), CINAHL Plus (EBSCOhost, 1937 onwards). There were no language restrictions. CRS Web includes randomised or quasi-randomised controlled trials from PubMed, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP), the Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialised Registers of Cochrane Review Groups including Epilepsy.  SELECTION CRITERIA: We included randomised controlled trials of stimulant and non-stimulant drugs for people of any age, gender or ethnicity with ADHD and co-occurring epilepsy.

DATA COLLECTION AND ANALYSIS

We selected articles and extracted data according to predefined criteria. We conducted primary analysis on an intention-to-treat basis. We presented outcomes as risk ratios (RRs) with 95% confidence intervals (CIs), except for individual adverse effects where we quoted 99% CIs. We conducted best- and worst-case sensitivity analyses to deal with missing data. We carried out a risk of bias assessment for each included study using the Cochrane risk of bias tool and assessed the overall certainty of evidence using the GRADE approach.

MAIN RESULTS

We identified two studies that matched our inclusion criteria: a USA study compared different doses of the stimulant drug osmotic-release oral system methylphenidate (OROS-MPH) with a placebo in 33 children (mean age 10.5 ± 3.0 years), and an Iranian study compared the non-stimulant drug omega-3 taken in conjunction with risperidone and usual anti-seizure medication (ASM) with risperidone and ASM only in 61 children (mean age 9.24 ± 0.15 years). All children were diagnosed with epilepsy and ADHD according to International League Against Epilepsy and Diagnostic and Statistical Manual of Mental Disorders, fourth edition, criteria, respectively. We assessed both studies to be at low risk of detection and reporting biases, but assessments varied from low to high risk of bias for all other domains. OROS-MPH No participant taking OROS-MPH experienced significant worsening of epilepsy, defined as: 1. a doubling of the highest 14-day or highest two-day seizure rate observed during the 12 months before the trial; 2. a generalised tonic-clonic seizure if none had been experienced in the previous two years; or 3. a clinically meaningful intensification in seizure duration or severity (33 participants, 1 study; low-certainty evidence). However, higher doses of OROS-MPH predicted an increased daily risk of a seizure (P < 0.001; 33 participants, 1 study; low-certainty evidence). OROS-MPH had a larger proportion of participants receiving 'much improved' or 'very much improved' scores for ADHD symptoms on the Clinical Global Impressions for ADHD-Improvement tool (33 participants, 1 study; low-certainty evidence). OROS-MPH also had a larger proportion of people withdrawing from treatment (RR 2.80; 95% CI 1.14 to 6.89; 33 participants, 1 study; moderate-certainty evidence). Omega-3 Omega-3 with risperidone and ASM were associated with a reduction in mean seizure frequency by 6.6 seizures per month (95% CI 4.24 to 8.96; 56 participants, 1 study; low-certainty evidence) and an increase in the proportion of people achieving 50% or greater reduction in monthly seizure frequency (RR 2.79, 95% CI 0.84 to 9.24; 56 participants, 1 study; low-certainty evidence) compared to people on risperidone and ASM alone. Omega-3 with risperidone and ASM also had a smaller proportion of people withdrawing from treatment (RR 0.65, 95% CI 0.12 to 3.59; 61 participants, 1 study; low-certainty evidence) but a larger proportion of people experiencing adverse drug events (RR 1.40, 95% CI 0.44 to 4.42; 56 participants, 1 study; low-certainty evidence) compared to people on risperidone and ASM alone.

AUTHORS' CONCLUSIONS

In children with a dual-diagnosis of epilepsy and ADHD, there is some evidence that use of the stimulant drug OROS-MPH is not associated with significant worsening of epilepsy, but higher doses of it may be associated with increased daily risk of seizures; the evidence is of low-certainty. OROS-MPH is also associated with improvement in ADHD symptoms. However, this treatment was also associated with a large proportion of treatment withdrawal compared to placebo. In relation to the non-stimulant drug omega-3, there is some evidence for reduction in seizure frequency in children who are also on risperidone and ASM, compared to children who are on risperidone and ASM alone. Evidence is inconclusive whether omega-3 increases or decreases the risk of adverse drug events. We identified only two studies - one each for OROS-MPH and omega-3 - with low to high risk of bias. We assessed the overall certainty of evidence for the outcomes of both OROS-MPH and omega-3 as low to moderate. More studies are needed. Future studies should include: 1. adult participants; 2. a wider variety of stimulant and non-stimulant drugs, such as amphetamines and atomoxetine, respectively; and 3. additional important outcomes, such as seizure-related hospitalisations and quality of life. Clusters of studies which assess the same drug - and those that build upon the evidence base presented in this review on OROS-MPH and omega-3 - are needed to allow for meta-analysis of outcomes.

Developmental Dyslexia: Disorder or Specialization in Exploration?

We raise the new possibility that people diagnosed with developmental dyslexia (DD) are specialized in explorative cognitive search, and rather than having a neurocognitive disorder, play an essential role in human adaptation. Most DD research has studied educational difficulties, with theories framing differences in neurocognitive processes as deficits. However, people with DD are also often proposed to have certain strengths - particularly in realms like discovery, invention, and creativity - that deficit-centered theories cannot explain. We investigate whether these strengths reflect an underlying explorative specialization. We re-examine experimental studies in psychology and neuroscience using the framework of cognitive search, whereby many psychological processes involve a trade-off between exploration and exploitation. We report evidence of an explorative bias in DD-associated cognitive strategies. High DD prevalence and an attendant explorative bias across multiple areas of cognition suggest the existence of explorative specialization. An evolutionary perspective explains the combination of findings and challenges the view that individuals with DD have a disorder. In cooperating groups, individual specialization is favored when features that confer fitness benefits are functionally incompatible. Evidence for search specialization suggests that, as with some other social organisms, humans mediate the exploration-exploitation trade-off by specializing in complementary strategies. The existence of a system of collective cognitive search that emerges through collaboration would help to explain our species' exceptional adaptiveness. It also aligns with evidence for substantial variability during our evolutionary history and the notion that humans are adapted not to a particular habitat but to variability itself. Specialization creates interdependence and necessitates balancing complementary strategies. Reframing DD therefore underscores the urgency of changing certain cultural practices to ensure we do not inhibit adaptation. Key improvements would remove cultural barriers to exploration and nurture explorative learning in education, academia, and the workplace, as well as emphasize collaboration over competition. Specialization in complementary search abilities represents a meta-adaptation; through collaboration, this likely enables human groups (as a species and as cultural systems) to successfully adapt. Cultural change to support this system of collaborative search may therefore be essential in confronting the challenges humanity now faces.

The Impact of COVID-19 on Anxiety and Worries for Families of Individuals with Special Education Needs and Disabilities in the UK

COVID-19 has affected people across the world. The current study examined anxiety and worries during the first UK national lockdown in March 2020. Parents (n = 402) reported on their own anxiety and worries as well as that of their son/daughter with Special Education Needs and Disabilities (SEND) and typically developing (TD) child (n = 186) at three time points. Although both groups showed increased anxiety across the three time points, levels of anxiety in the SEND group, but not the TD siblings, were predicted by awareness about COVID-19. In addition, worries differed between the groups showing that COVID-19 impacts the wellbeing of those with SEND differently to that of their TD siblings.

Meta-analysis: Dose-Dependent Effects of Methylphenidate on Neurocognitive Functioning in Children With Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Neurocognitive deficits are at the heart of explanatory models of attention-deficit/hyperactivity disorder (ADHD), and lead to significant impairments in daily life. Determining the dosing effects of methylphenidate (MPH) on a broad range of neurocognitive functions and investigating possible impairing effects of high doses is therefore important.

METHOD

Placebo-controlled trials were included that investigated MPH dosing effects on neurocognitive functions in children and adolescents (aged 5-18 years) diagnosed with ADHD. Effect sizes (standardized mean differences [SMDs]) were calculated for different neurocognitive functions (baseline speed, variability in responding, nonexecutive memory and executive memory, inhibitory control, and cognitive flexibility) and, if available, for ADHD symptoms. Meta-regression analysis were used to investigate linear effects of dose (mg/kg/dose), and separate meta-analyses compared SMDs for 3 MPH dose ranges: low (0.10-0.30 mg/kg/dose), medium (0.31-0.60 mg/kg/dose), and high (0.61-1.00 mg/kg/dose).

RESULTS

A total of 31 studies fulfilled inclusion criteria, comprising 804 children with ADHD. Methylphenidate had beneficial effects on all neurocognitive functions (d = 0.20-0.73). Significant linear dosing effects were found for ADHD symptoms and lower-order neurocognitive functions (baseline speed, variability in responding, nonexecutive memory), with greater enhancement of functioning with increasing dose. No dosing effects were found for higher-order neurocognitive functions (executive memory, inhibitory control, and cognitive flexibility). No detrimental effects of MPH were found on any of the investigated functions.

CONCLUSION

Methylphenidate was superior to placebo in improving ADHD symptoms and a broad range of neurocognitive functions; however, effects sizes regarding the effects of dose vary substantially between functions. Our data highlight the importance of considering both neurocognitive and symptomatic aspects of ADHD in clinical practice.

Relationships between cognition and literacy in children with attention-deficit/hyperactivity disorder: A systematic review and meta-analysis

Evidence suggests that cognitive and literacy difficulties are common for children with Attention-Deficit/Hyperactivity Disorder (ADHD). The current systematic review and meta-analysis investigated the relationship between cognition and literacy in children with ADHD. Ten thousand and thirty-eight articles were screened against the inclusion criteria and six eligible studies were retained for final review. Where two or more studies used comparable measures of cognition and literacy, a meta-analysis of the relationship between these measures was undertaken. A narrative synthesis of all included studies was also completed. There were medium effect sizes between working memory and aspects of reading, and small effect sizes between processing speed and reading. Inhibition and attention had differential relationships with aspects of literacy with varying effect sizes. This systematic review demonstrates differential relationships between aspects of literacy and cognition in children with ADHD. Further examination of these relationships is warranted to support intervention development.

Examining Distinctive Working Memory Profiles in Chinese Children With Predominantly Inattentive Subtype of Attention-Deficit/Hyperactivity Disorder and/or Reading Difficulties

Although evidence has shown that both RD and ADHD-I children suffer from working memory problems, inconsistencies in impaired modalities have been reported. This study aimed to (1) compare the three WM domains (i.e., verbal WM, visual-spatial WM, and behavioral WM) among pure ADHD-I, pure RD, comorbid ADHD-I+RD, and typical control groups and (2) examine the impact of comorbidity on the three WM domains. A Chinese sample of participants from Hong Kong included 29 children in the ADHD-I group, 78 children in the RD group, 31 children in the comorbid group (ADHD-I+RD), and 64 children in the TD control group. All participants completed the assessments individually. The findings showed that the children with ADHD-I and/or RD exhibited diverse cognitive profiles. In particular, RD was associated with verbal and visual-spatial working memory deficits, while ADHD-I was associated with behavioral working memory deficits. Interestingly, the comorbid condition demonstrated additive deficits of the two disorders but with greater deficits in behavioral working memory. These findings support the cognitive subtype hypothesis and provide a clearer picture of the distinctive working memory profiles of different groups, allowing for the development of intervention programs in the future.

The relationship between cognition and mathematics in children with attention-deficit/hyperactivity disorder: a systematic review

Cognitive processes play an imperative role in children's mathematics learning. Difficulties in cognitive functioning are a core feature of Attention Deficit Hyperactivity Disorder (ADHD) in children, who also tend to show lower levels of mathematics attainment than their typically developing peers. This review (registration number: CRD42020169708) sought to aggregate findings from studies assessing the relationship between cognition and mathematics in children with a clinical ADHD diagnosis aged 4-12 years. A total of 11,799 studies published between 1992 and August 2020 were screened for eligibility using various database (PsycINFO, PubMed, SCOPUS, EMBASE, ERIC, Web of Science, and additional sources), from which four studies met inclusion criteria. A narrative synthesis was conducted on the correlations between mathematics and cognitive domains, including an evaluation of the risk of bias within the studies. Across four studies meeting inclusion criteria, memory, inhibitory control, and processing speed were assessed. The results showed a positive association between cognition and mathematics performance in this population. The strength of associations across these studies varied as a function of the cognitive domain in question, means by which mathematics performance was assessed, as well as whether confounding factors such as age and IQ were controlled for. Collectively, this review demonstrates a lack of research in this area and points to various methodological considerations for identifying the association between cognition and mathematics performance in ADHD.

Childhood Antisocial Behavior: A Neurodevelopmental Problem

Early-onset disruptive, aggressive, and antisocial behavior is persistent, can become increasingly serious as children grow older, and is difficult to change. In 2007, our group proposed a theoretical model highlighting the interplay between neurobiological deficits and cognitive and emotional functioning as mediators of the link between genetic influences and early social adversity, on the one hand, and antisocial behavioral problems in childhood, on the other. In this article, we review the post-2007 evidence relevant to this model. We discuss research on genetics/epigenetics, stress/arousal regulation, and emotion and executive functioning in support of the argument that antisocial children, especially those who persist in engaging in antisocial behavior as they grow older, have a range of neuropsychological characteristics that are important in explaining individual differences in the severity and persistence of antisocial behavior. Current clinical practice tends not to acknowledge these individual neuropsychological risks factors or to target them for intervention. We argue that aggressive and disruptive behavior in childhood should be regarded as a neurodevelopmental problem and that intervening at the level of mediating neuropsychological processes represents a promising way forward in tackling these serious behavioral problems. Expected final online publication date for the Annual Review of Psychology, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Low striatal T3 is implicated in inattention and memory impairment in an ADHD mouse model overexpressing thyroid hormone-responsive protein

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder, potentially with a biological basis; however, its exact cause remains unknown. Thyroid hormone (TH) abnormalities are more prevalent in patients with ADHD than in the general population, indicating a shared pathogenetic mechanism for these conditions. Previously, we identified that overexpression of thyroid hormone-responsive protein (THRSP), a gene highly responsive to TH status, induced inattention in male mice. Herein, we sought to explore whether TH function in THRSP-overexpressing (THRSP OE) mice influences ADHD-like (inattention) behavior. We now confirm that THRSP overexpression in male mice reproduces behavioral features of ADHD, including sustained inattention and memory impairment, accompanied by excessive theta waves that were found normal in both the THRSP-knockout and hetero groups. Physiological characterization revealed low striatal T3 levels in the THRSP OE mice due to reduced striatal T3-specific monocarboxylate transporter 8 (MCT8), indicating brain-specific hypothyroidism in this transgenic mouse strain. TH replacement for seven days rescued inattention and memory impairment and the normalization of theta waves. This study further supports the involvement of the upregulated THRSP gene in ADHD pathology and indicates that THRSP OE mice can serve as an animal model for the predominantly inattentive subtype of ADHD.

[Formula: see text]Systematic review of pediatric memory questionnaires

Memory disturbances are common in children with neurological and developmental conditions. One way to measure memory disturbances and their functional implications is via a memory questionnaire. Several pediatric memory questionnaires have been published but no systematic review has been conducted to establish their psychometric properties. This review evaluated currently available pediatric memory questionnaires using the Evidence-Based Assessment (EBA) criteria developed by the American Psychological Association Task force. A systematic search of CINAHL, EMBASE, Medline, and PsychINFO was completed on June 2019. The selection process was guided by pre-defined inclusion and exclusion criteria, followed by full manuscript reviews, and hand-search of reference lists of relevant papers. Selected questionnaires were evaluated by two independent raters against the EBA criteria and classified into "well established", "approaching well-established", and "promising" categories. The electronic searches yielded 9888 articles, 24 of which met the inclusion criteria. Hand searches identified additional 21 studies. The 45 identified studies reported on 24 versions of 10 memory questionnaires assessed working memory, everyday memory, prospective and retrospective memory, and self-awareness of memory functions. Based on EBA criteria, only one memory questionnaire (The Working Memory Rating Scale - 20 item version) was classified as "well-established", 3 as "approaching well-established", and 20 as "promising". Most (n = 19) had good reliability but lacked concurrent validity; had low or no correlations with objective memory tests, and low predictive power. In conclusion, this review highlights an urgent need for the development and validation of pediatric memory questionnaires to increase the evidence base and improve questionnaires' clinical utility.

Verbal working memory and processing speed: Correlations with the severity of attention deficit and emotional dysregulation in adult ADHD

Objectives

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM‐5), emphasizes symptoms severity with regard to the diagnosis of attention deficit hyperactivity disorder (ADHD). Many clinicians use neuropsychological test results as objective measures of cognitive functions as part of the diagnostic work‐up. The aim of this study was to investigate whether the psychometric test results regarding verbal working memory and processing speed are useful as indicators of the severity of attention deficits and emotional dysregulation in adults with ADHD.

Methods

This observational cross‐sectional clinical study included 418 adults diagnosed with ADHD according to the DSM‐5. Attention deficit severity was defined based on the inattentive subscale of the Adult ADHD Self‐Report Scale. Emotional dysregulation was assessed with the Deficient Emotional Self‐Regulation scale. Verbal working memory was measured with the Working Memory Index (WMI), and processing speed was measured with the Processing Speed Index (PSI) from the Wechsler Adult Intelligence Scale, third edition.

Results

The full‐scale intelligence quotients of the participants were in the normal range, with expected reductions in verbal working memory and processing speed. Only processing speed was associated with attention deficits (β = −.056, p = .003). The association between the psychometric test result for verbal working memory and processing speed and that between the severity of attention deficits and emotional dysregulation were weak (R² < .1) and mostly non‐significant.

Conclusion

The psychometric index scores for verbal working memory (WMI) and processing speed (PSI) seem to have limited utility as indicators of the severity of attention deficits and emotional dysregulation in adult ADHD patients.

Recognition memory for pictures in children with ADHD: an event-related potential study

OBJECTIVE

Children with ADHD are reported to accompany by various degrees of recognition memory cognitive deficits. We aimed to investigate age-related changes of the amplitude in event-related potential recordings on recognition memory in Chinese children with ADHD and to provide theoretical basis of neuro-electrophysiology for the cognition development of children.

METHOD

ERP and behavioral data of 6- to -10-year-old children with ADHD (n = 94) and typically developing controls (TD, n = 96) were collected while the children performed a classical visual study-test paradigm task.

RESULTS

Children with ADHD have defects in pictures recognition and showed a significantly smaller P2 component than that of TD children. The development of P2 and P3 component were different between the two groups. Moreover, the TD children showed the frontal old/new effect (N2) taken as a correlate of familiarity at 6 years old, and a parietal old/new effect (P3) taken as a correlate of recollection at 9 years old, while children with ADHD showed a parietal old/new effect (P3) only at 6 years old.

CONCLUSION

Our study provided the novel evidence that recognition memory follow different developmental trajectories at the age of 6-10 between TD and ADHD.

Transcutaneous vagus nerve stimulation in patients with attention-deficit/hyperactivity disorder: A viable option?

Individuals with attention-deficit/hyperactivity disorder (ADHD) suffer from a range of cognitive and behavioral problems that severely impair their educational and occupational attainment. ADHD symptoms have been linked to structural and functional changes within and between different brain regions, particularly the prefrontal cortex. At the system level, reduced availability of the neurotransmitters dopamine (DA) and norepinephrine (NE) but also γ-aminobutyric acid (GABA) have been repeatedly demonstrated. Recently, non-invasive brain stimulation (NIBS) techniques have been explored as treatment alternatives to alter dysfunctional activation patterns in specified brain areas or networks. In the current paper, we introduce transcutaneous vagus nerve stimulation (tVNS) as a systemic approach to directly affect NE and GABA neurotransmission. TVNS is a non-drug intervention with low risk and proven efficacy in improving cognitive particularly executive functions. It is easy to apply and therefore well-suited to provide home-based or mobile treatment options allowing a significant increase in treatment intensity and providing easier access to medical care for individuals who are unable to regularly visit a clinician. We describe in detail the underlying mechanisms of tVNS and current fields of application and discuss its potential as an adjuvant treatment for ADHD.

An ecological momentary assessment study of the role of emotional dysregulation in co-occurring ADHD and internalising symptoms in adulthood

Previous ecological momentary assessment (EMA) research in children has suggested that emotional dysregulation problems are commonly associated with ADHD symptoms and may help explain their relatively strong co-occurrence with anxiety and depression (collectively referred to as 'internalising problems'); however, this has yet to be replicated for adults. In this study, we used data from a n=260 longitudinal cohort and EMA study, to evaluate the hypothesis that emotional dysregulation mediates the association between ADHD symptoms and internalising problems in emerging adulthood. Emotional dysregulation was based on affect data collected in near real time and in ecological context over a 14-day period, providing a measure of emotional lability in the context of participants' daily lives. Cross-sectional mediation was tested using structural equation modelling. Emotional lability significantly mediated the association between ADHD symptoms and internalising problems. Results suggest that interventions that address the emotional dysregulation aspects of ADHD are likely to be beneficial for preventing and managing secondary internalising symptoms.

Link Between Topographic Memory and the Combined Presentation of ADHD (ADHD-C): A Pilot Study

Background: Topographic memory is the ability to reach various places by recognizing spatial layouts and getting oriented in familiar environments. It involves several different cognitive abilities, in particular executive functions (EF), such as attention, working memory, and planning. Children with attention deficit hyperactivity disorder (ADHD) show impairments in inhibitory control, regulation of attention, planning, and working memory. Aim: The aim of this study was to evaluate the topographic memory in children with ADHD-combined subtype (ADHD-C). Method: Fifteen children (8-10 years) with a diagnosis of ADHD-C (DSM-5) (ADHD-C group) were compared to 15 children with typical development (TD group) of the same age. All children performed Raven's colored progressive matrices (CPM) test to obtain a measure related with cognitive functioning. The walking Corsi test (WalCT), a large-scale version of the Corsi block-tapping test, was used to assess topographic memory in experimental environment. Results: A higher impairment was observed in ADHD-C than TD with significant differences in the WalCT, in particular on the topographic short-term memory (TSTM) task, on the topographic learning (TL) task, and on the repetition number (RN) task during the TL task. Perseverative errors were reported in performing the square-sequence in the WalCT. Zero-order correlations showed a positive correlation between TSTM and auditory attention, and memory of design of NEPSY-II and digit span of WISC-IV. No statistically significant differences were found between the ADHD-C group and TD group in the TL task in the WalCT condition. Conclusion: In ADHD-C, initial topographic learning was compromised whereas the long-term retention of learned topographical material seemed to not be impaired. In particular, these impairments seem to be linked with difficulties in sustained attention, in spatial memory for novel visual materials, in a poor working memory, and in perseverative behaviors.

ADHD: Current Concepts and Treatments in Children and Adolescents

Attention deficit hyperactivity disorder (ADHD) is among the most frequent disorders within child and adolescent psychiatry, with a prevalence of over 5%. Nosological systems, such as the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) and the International Classification of Diseases, editions 10 and 11 (ICD-10/11) continue to define ADHD according to behavioral criteria, based on observation and on informant reports. Despite an overwhelming body of research on ADHD over the last 10 to 20 years, valid neurobiological markers or other objective criteria that may lead to unequivocal diagnostic classification are still lacking. On the contrary, the concept of ADHD seems to have become broader and more heterogeneous. Thus, the diagnosis and treatment of ADHD are still challenging for clinicians, necessitating increased reliance on their expertise and experience. The first part of this review presents an overview of the current definitions of the disorder (DSM-5, ICD-10/11). Furthermore, it discusses more controversial aspects of the construct of ADHD, including the dimensional versus categorical approach, alternative ADHD constructs, and aspects pertaining to epidemiology and prevalence. The second part focuses on comorbidities, on the difficulty of distinguishing between "primary" and "secondary" ADHD for purposes of differential diagnosis, and on clinical diagnostic procedures. In the third and most prominent part, an overview of current neurobiological concepts of ADHD is given, including neuropsychological and neurophysiological researches and summaries of current neuroimaging and genetic studies. Finally, treatment options are reviewed, including a discussion of multimodal, pharmacological, and nonpharmacological interventions and their evidence base.

Executive functioning and emotion recognition in youth with oppositional defiant disorder and/or conduct disorder

Objectives: Executive functioning and emotion recognition may be impaired in disruptive youth, yet findings in oppositional defiant disorder (ODD) and conduct disorder (CD) are inconsistent. We examined these functions related to ODD and CD, accounting for comorbid attention-deficit/hyperactivity disorder (ADHD) and internalising symptoms.Methods: We compared executive functioning (visual working memory, visual attention, inhibitory control) and emotion recognition between youth (8-18 years old, 123 boys, 55 girls) with ODD (n = 44) or CD (with/without ODD, n = 48), and healthy controls (n = 86). We also related ODD, CD, and ADHD symptom counts and internalising symptomatology to all outcome measures, as well as executive functioning to emotion recognition.Results: Visual working memory and inhibitory control were impaired in the ODD and CD groups versus healthy controls. Anger, disgust, fear, happiness, and sadness recognition were impaired in the CD group; only anger recognition was impaired in the ODD group. Deficits were not explained by comorbid ADHD or internalising symptoms. Visual working memory was associated with recognition of all basic emotions.Conclusions: Our findings challenge the view that neuropsychological impairments in youth with ODD/CD are driven by comorbid ADHD and suggest possible distinct neurocognitive mechanisms in CD versus ODD.

Neurocognitive Deficits in Attention-Deficit/Hyperactivity Disorder With and Without Comorbid Oppositional Defiant Disorder

Objective: Oppositional Defiant Disorder (ODD) is highly prevalent in Attention-Deficit/Hyperactivity Disorder (ADHD) and may account for inconsistencies in findings on neurocognitive functioning in ADHD. Our aim was to assess cool and hot executive functioning (EF) and temporal processing in ADHD with and without comorbid ODD to elucidate the effects of comorbid ODD. Method: ADHD-only (n = 82), ADHD + ODD (n = 82), and controls (n = 82), with mean age 16 years (SD = 3.1), matched for age, gender, IQ, and ADHD type (clinical groups) were assessed on cool EF (inhibition, working memory), hot EF (reinforcement processing, emotion recognition), and temporal processing (time production and reproduction). Results: Individuals with ADHD + ODD showed abnormalities in inhibition, working memory, facial emotion recognition, and temporal processing, whereas individuals with ADHD-only were solely impaired in working memory and time production. Conclusion: Findings suggest that ODD carries a substantial part of the EF deficits observed in ADHD and contrast with current theories of neurocognitive impairments in ADHD.

Maturational delay and asymmetric information flow of brain connectivity in SHR model of ADHD revealed by topological analysis of metabolic networks

Attention-deficit hyperactivity disorder (ADHD) is a complex brain development disorder characterized by hyperactivity/impulsivity and inattention. A major hypothesis of ADHD is a lag of maturation, which is supported mainly by anatomical studies evaluating cortical thickness. Here, we analyzed changes of topological characteristics of whole-brain metabolic connectivity in twelve SHR rats selected as ADHD-model rats by confirming behavior abnormalities using the marble burying test, open field test, and delay discounting task and 12 Wistar Kyoto rats as the control group, across development from 4 weeks old (childhood) and 6 weeks old (entry of puberty). A topological approach based on graph filtrations revealed a lag in the strengthening of limbic-cortical/subcortical connections in ADHD-model rats. This in turn related to impaired modularization of memory and reward-motivation associated regions. Using mathematical network analysis techniques such as single linkage hierarchical clustering and volume entropy, we observed left-lateralized connectivity in the ADHD-model rats at 6 weeks old. Our findings supported the maturational delay of metabolic connectivity in the SHR model of ADHD, and also suggested the possibility of impaired and compensative reconfiguration of information flow over the brain network.

Dopamine and norepinephrine transporter inhibition for long-term fear memory enhancement

Psychostimulants are highly effective cognitive-enhancing therapeutics yet have a significant potential for abuse and addiction. While psychostimulants likely exert their rewarding and addictive properties through dopamine transporter (DAT) inhibition, the mechanisms of their procognitive effects are less certain. By one prevalent view, psychostimulants exert their procognitive effects exclusively through norepinephrine transporter (NET) inhibition, however increasing evidence suggests that DAT also plays a critical role in their cognitive-enhancing properties, including long-term memory enhancement. The present experiments test the hypothesis that combined strong NET and weak DAT inhibition will mimic the fear memory-enhancing but not the addiction-related effects of psychostimulants in mice. We examined the effects of the high affinity NET inhibitors atomoxetine or nisoxetine and the low affinity DAT inhibitor bupropion, either alone or in combination, on short- and long-term memory of Pavlovian fear conditioning. We also examined the addiction-related effects of combined strong NET and weak DAT inhibition using conditioned place preference and a locomotor activity test. While atomoxetine or nisoxetine alone enhanced short-term fear memory, the addition of bupropion was required to significantly enhance long-term fear memory. Additionally, combined atomoxetine and bupropion did not produce substantial motor stimulation or place preference. These findings suggest that combining strong NET and weak DAT inhibition could lead to the development of a highly effective cognitive enhancer that lacks the potential for addiction.

Basic processes as foundations of cognitive impairment in adult ADHD

Attention deficit hyperactivity disorder (ADHD) in adulthood is associated with impairment of multiple aspects of cognition which adversely affect the individual's everyday functioning. However, little is known about how these impairments are intertwined. This study explores whether impairments in basic processes (processing speed and distractibility) in adults with ADHD explain impairments in higher order functions, namely executive functions, memory, and complex attention. Furthermore, it is explored whether pharmacological treatment with methylphenidate (MPH) affects basic processes and higher order functions. A between-subjects design compared patients with ADHD without stimulant drug treatment (N = 55) and patients with ADHD treated with MPH (N = 31) with a healthy control group (N = 80). A neuropsychological test battery assessing basic processes and higher order functions was administered. Hierarchical logistic regression analyses were performed to evaluate the contribution of basic processes to impairments in higher order functions. Patients with ADHD not treated with MPH showed impairments in basic processes and higher order functions compared to controls. The impairments in basic processes explained 41-43% of impairments in executive functions, 27-29% in memory, and 56-74% in complex attention. In patients with ADHD treated with MPH, basic processes were not impaired and did not contribute significantly to impairments of higher order functions. Basic processes may constitute part of the foundation of cognitive impairments in adult ADHD. MPH may improve cognitive performance, presumably through improving basic processes. Applying this information could optimize neuropsychological assessments and inform treatment strategies by targeting basic processes.

Inattentive Behavior in Boys with ADHD during Classroom Instruction: the Mediating Role of Working Memory Processes

Children with ADHD exhibit clinically impairing inattentive behavior during classroom instruction and in other cognitively demanding contexts. However, there have been surprisingly few attempts to validate anecdotal parent/teacher reports of intact sustained attention during 'preferred' activities such as watching movies. The current investigation addresses this omission, and provides an initial test of how ADHD-related working memory deficits contribute to inattentive behavior during classroom instruction. Boys ages 8-12 (M = 9.62, SD = 1.22) with ADHD (n = 32) and typically developing boys (TD; n = 30) completed a counterbalanced series of working memory tests and watched two videos on separate assessment days: an analogue math instructional video, and a non-instructional video selected to match the content and cognitive demands of parent/teacher-described 'preferred' activities. Objective, reliable observations of attentive behavior revealed no between-group differences during the non-instructional video (d = -0.02), and attentive behavior during the non-instructional video was unrelated to all working memory variables (r = -0.11 to 0.19, ns). In contrast, the ADHD group showed disproportionate attentive behavior decrements during analogue classroom instruction (d = -0.71). Bias-corrected, bootstrapped, serial mediation revealed that 59% of this between-group difference was attributable to ADHD-related impairments in central executive working memory, both directly (ER = 41%) and indirectly via its role in coordinating phonological short-term memory (ER = 15%). Between-group attentive behavior differences were no longer detectable after accounting for ADHD-related working memory impairments (d = -0.29, ns). Results confirm anecdotal reports of intact sustained attention during activities that place minimal demands on working memory, and indicate that ADHD children's inattention during analogue classroom instruction is related, in large part, to their underdeveloped working memory abilities.

Sequenced neurocognitive and behavioral parent training for the treatment of ADHD in school-age children

The present study examines the potential of sequencing a neurocognitive intervention with behavioral parent training (BPT) to improve executive functions (EFs), psychiatric symptoms, and multiple indices of functional impairment in school-age children aged 7 to 11 years who have been diagnosed with attention-deficit/hyperactivity disorder (ADHD). Specifically, in a randomized controlled trial design, 85 children were assigned to either Cogmed Working Memory Training (CWMT) followed by an empirically supported, manualized BPT intervention, or to a placebo version of CWMT followed by the same BPT intervention. Working memory maintenance (i.e., attention control/short-term memory), working memory processing and manipulation, ADHD and oppositional defiant disorder (ODD) symptoms, impairment in parent-child dynamics, familial impairment, and overall functional compromise were evaluated as outcomes. The results suggest specific effects of the combined CWMT and BPT program on verbal and nonverbal working memory storage and nonverbal working memory processing and manipulation but no incremental benefits in regard to ADHD symptoms, ODD symptoms, and functional outcomes. The present findings do not support the hypothesis regarding the complementary and augmentative benefits of sequenced neurocognitive and BPT interventions for the treatment of ADHD. These results, the study's limitations, and future directions for research are further discussed.

Comparing working memory in bilingual and monolingual Hispanic/Latino preschoolers with disruptive behavior disorders

The current study examined differences in working memory (WM) between monolingual and bilingual Hispanic/Latino preschoolers with disruptive behavior disorders (DBDs). A total of 149 children (Mage = 5.10 years, SD = 0.53; 76% male) with elevated levels of DBDs, as indicated by their parents or teachers, were recruited to participate in an 8-week summer program prior to the start of kindergarten (Summer Treatment Program for Pre-Kindergarteners). Prior to the start of treatment, parents completed several measures about their children's behavior and executive function, and children were administered two subtests of the Automated Working Memory Assessment to examine their current WM capabilities. After controlling for demographic variables (i.e., age, sex, socioeconomic status, IQ, and diagnostic status), no significant differences were observed between bilingual and monolingual children in verbal WM performance (β = .03, p > .05). However, children who were bilingual did perform better than monolinguals on spatial WM tasks (β = .23, p < .01). Finally, parent reports of WM corroborated these findings such that bilingual children were reported as having fewer WM problems by parents (β = -.19, p < .05) and teachers (β = -.22, p < .05). Whereas WM deficits are often found among children with DBDs, the current findings suggest that bilingualism may serve as a protective factor for preschoolers with DBDs.

Cognitive Functioning in Adolescents with Self-Reported ADHD and Depression: Results from a Population-Based Study

This study aims to assess cognitive functioning differences among adolescents with retrospectively self-reported: ADHD and an onset of depression, only ADHD, only depression, and neither ADHD nor depression. Data from the Tracking Adolescents’ Individual Lives Survey (TRAILS) cohort was used in this study. Neuropsychological functioning was assessed in 1549 adolescents, at baseline and follow-up (mean ages 11 and 19 years). The Composite International Diagnostic Interview was used to classify adolescents into 4 groups: ADHD with onset of depression, only ADHD, only depression, and neither ADHD nor depression. Linear mixed effects models were used to analyse group differences in cognitive functioning at baseline and follow-up, and the change in cognitive functioning between these 2 time-points. Results showed a significant main effect of group on response time variability at baseline, working memory maintenance at follow up, and change in response time variability scores between baseline and follow-up. As compared to the healthy and depressed-only groups, adolescents with only ADHD showed longer response time variability at baseline and, which declined between baseline and follow-up. Adolescents with ADHD plus depression showed higher reaction time for working memory maintenance than the depressed only and healthy groups at follow-up. In conclusion, adolescents with self-reported ADHD show poorer cognitive functioning than healthy adolescents and those with only depression. Amongst adolescents with ADHD, specific cognitive domains show poor functioning depending on the presence or absence of comorbid depression. While adolescents with only ADHD have lower reaction time variability, those with comorbid depression have poorer working memory maintenance.

Differential neuropsychological functioning between adolescents with attention-deficit/hyperactivity disorder with and without conduct disorder

BACKGROUND/PURPOSE

This study aimed to evaluate neuropsychological functioning of attention-deficit/hyperactivity disorder (ADHD) with and without comorbidities of oppositional defiant disorder (ODD) and/or conduct disorder (CD) and the mediation effects of the neuropsychological functions in the relationship between ADHD and ODD/CD symptoms to increase our understanding about these frequently co-occurring disorders.

METHODS

Adolescents aged 11-18 years were interviewed by the Kiddie epidemiologic version of the Schedule for Affective Disorders and Schizophrenia to confirm their previous and current ADHD status and other psychiatric diagnoses. The performance of the Cambridge Neuropsychological Testing Automated Battery was compared among four groups: (1) ADHD with CD (ADHD+CD), regardless of ODD; (2) ADHD with ODD (ADHD+ODD) without CD; (3) ADHD without ODD/CD (ADHD-only); and (4) typically developing controls. Mediation effects of neuropsychological functioning were tested.

RESULTS

All three ADHD groups had impaired spatial working memory and short-term memory. Deficits in verbal memory and response inhibition were found in ADHD+ODD, but not in ADHD-only. ADHD+CD did not differ from typically developing controls in verbal working memory, signal detectability, and response inhibition. Spatial working memory partially mediated the association between ADHD and CD symptoms and alerting/signal detectability of arousal partially mediated the association between ADHD and ODD symptoms.

CONCLUSION

There were both common and distinct neuropsychological deficits between adolescents with ADHD who developed ODD only and who developed CD. ADHD comorbid with CD may be a different disease entity and needs different treatment strategies in addition to treating ADHD, while ADHD+ODD may be a severe form of ADHD and warrants intensive treatment for ADHD symptoms.

Attention and Executive Function in Children Diagnosed with Attention Deficit Hyperactivity Disorder and Comorbid Disorders

OBJECTIVE

The goal of this study was to examine the relationship between comorbid disorders and executive function (EF) in children diagnosed with Attention Deficit/Hyperactivity Disorder (ADHD).

METHODS

Three hundred and fifty-five, 6-12 year old children clinically diagnosed with ADHD were included in the study. Comorbid anxiety disorders, Oppositional Defiant Disorder (ODD) and Conduct Disorder (CD) were examined. The EF domains were assessed using the Conners' Continuous Performance Test (CPT), Wisconsin Card Sorting Test (WCST), Tower of London (ToL), Finger Windows (FW) and Self Ordered Pointing Test (SOPT).

RESULTS

The findings indicate that children with comorbid anxiety disorders performed worse in domains measured by CPT and prior to controlling for age and sex, by FW. However, once sex was controlled for the results for FW were no longer significant. Children with CD obtained lower scores on WCST. Furthermore, a significant sex by CD interaction was observed.

CONCLUSION

These results indicate that comorbid disorders should be carefully examined as they play a significant role in EF performance and subsequently in day-to-day functioning of children with ADHD.

Emotional Regulation and Executive Function Deficits in Unmedicated Chinese Children with Oppositional Defiant Disorder

OBJECTIVE

This study aims to explore the feature of emotional regulation and executive functions in oppositional defiant disorder (ODD) children.

METHODS

The emotional regulation and executive functions of adolescents with ODD, as well as the relationship between the two factors were analyzed using tools including Adolescent Daily Emotional Regulation Questionnaire (ADERQ), Wisconsin Card Sorting Test (WCST) and Cambridge Neuropsychological Test Automated Battery (CANTAB), in comparison with attention deficit hyperactivity disorder (ADHD) children without behavioral problem and healthy children; the ADERQ assessed emotional regulation ability and others were used to assess executive function.

RESULTS

Compared to normal children, the ODD group displayed significant differences in the scores of cognitive reappraisal, rumination, expressive suppression, and revealing of negative emotions, as well as in the score of cognitive reappraisal of positive emotions. WCST perseverative errors were well correlated with rumination of negative emotions (r=0.47). Logistic regression revealed that the minimum number of moves in the Stocking of Cambridge (SOC) test (one test in CANTAB) and negative emotion revealing, were strongly associated with ODD diagnosis.

CONCLUSION

Children with ODD showed emotion dysregulation, with negative emotion dysregulation as the main feature. Emotion dysregulation and the lack of ability to plan lead to executive function deficits. The executive function deficits may guide us to understand the deep mechanism under ODD.

A rating measure of ADHD-related neuropsychological impairment in children and adolescents: Data from the Cognition and Motivation in Everyday Life (CAMEL) Scale from population and clinical samples

A new parent-completed questionnaire, the Cognition and Motivation in Everyday Life (CAMEL) scale, was developed to provide a comprehensive assessment of neuropsychological impairment in children related to attention-deficit/hyperactivity disorder (ADHD) across diverse cognitive, motivational and energetic domains. Its psychometric properties were investigated. A total of 60 items were generated to cover a wide range of putative ADHD-related neuropsychological processes. A clinical (n = 142) and community (n = 810) sample of parents with children between 6 and 16 years of age completed the questionnaire. Data on ADHD symptoms were also collected with a commonly-used, validated parent rating scale to explore the associations between CAMEL scores and dimensional measures of child ADHD and conduct problems. Factor analysis identified six factors which we labeled (i) Cognition, (ii) Self-Direction and Organization, (iii) Effort Engagement, (iv) Arousal Regulation, (v) Motivational Responsiveness, and (vi) Cautiousness. Self-Direction and Organization and Arousal Regulation were the strongest predictors for ADHD symptomatology. Self-Direction and Organization was strongly associated with inattention and Arousal Regulation with hyperactivity-impulsivity symptoms. Parents distinguished between broad neuropsychological domains in reliable and plausible ways, making distinctions between key aspects of functioning. However, the boundaries between these domains did not map directly onto the distinctions drawn within traditional models of ADHD deficits. Further research is required to examine the predictive validity and cost-effectiveness of the CAMEL scale compared to direct objective testing using laboratory measures in predicting prognosis and treatment outcome.

Attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a childhood-onset neurodevelopmental disorder with a prevalence of 1·4-3·0%. It is more common in boys than girls. Comorbidity with childhood-onset neurodevelopmental disorders and psychiatric disorders is substantial. ADHD is highly heritable and multifactorial; multiple genes and non-inherited factors contribute to the disorder. Prenatal and perinatal factors have been implicated as risks, but definite causes remain unknown. Most guidelines recommend a stepwise approach to treatment, beginning with non-drug interventions and then moving to pharmacological treatment in those most severely affected. Randomised controlled trials show short-term benefits of stimulant medication and atomoxetine. Meta-analyses of blinded trials of non-drug treatments have not yet proven the efficacy of such interventions. Longitudinal studies of ADHD show heightened risk of multiple mental health and social difficulties as well as premature mortality in adult life.

Good Holders, Bad Shufflers: An Examination of Working Memory Processes and Modalities in Children with and without Attention-Deficit/Hyperactivity Disorder

The aim of this study was to examine working memory (WM) modalities (visual-spatial and auditory-verbal) and processes (maintenance and manipulation) in children with and without attention-deficit/hyperactivity disorder (ADHD). The sample consisted of 63 8-year-old children with ADHD and an age- and sex-matched non-ADHD comparison group (N=51). Auditory-verbal and visual-spatial WM were assessed using the Digit Span and Spatial Span subtests from the Wechsler Intelligence Scale for Children Integrated - Fourth Edition. WM maintenance and manipulation were assessed via forward and backward span indices, respectively. Data were analyzed using a 3-way Group (ADHD vs. non-ADHD)×Modality (Auditory-Verbal vs. Visual-Spatial)×Condition (Forward vs. Backward) Analysis of Variance (ANOVA). Secondary analyses examined differences between Combined and Predominantly Inattentive ADHD presentations. Significant Group×Condition (p=.02) and Group×Modality (p=.03) interactions indicated differentially poorer performance by those with ADHD on backward relative to forward and visual-spatial relative to auditory-verbal tasks, respectively. The 3-way interaction was not significant. Analyses targeting ADHD presentations yielded a significant Group×Condition interaction (p=.009) such that children with ADHD-Predominantly Inattentive Presentation performed differentially poorer on backward relative to forward tasks compared to the children with ADHD-Combined Presentation. Findings indicate a specific pattern of WM weaknesses (i.e., WM manipulation and visual-spatial tasks) for children with ADHD. Furthermore, differential patterns of WM performance were found for children with ADHD-Predominantly Inattentive versus Combined Presentations. (JINS, 2016, 22, 1-11).

The impact of neuroscience on society: cognitive enhancement in neuropsychiatric disorders and in healthy people

In addition to causing distress and disability to the individual, neuropsychiatric disorders are also extremely expensive to society and governments. These disorders are both common and debilitating and impact on cognition, functionality and wellbeing. Cognitive enhancing drugs, such as cholinesterase inhibitors and methylphenidate, are used to treat cognitive dysfunction in Alzheimer's disease and attention deficit hyperactivity disorder, respectively. Other cognitive enhancers include specific computerized cognitive training and devices. An example of a novel form of cognitive enhancement using the technological advancement of a game on an iPad that also acts to increase motivation is presented. Cognitive enhancing drugs, such as methylphenidate and modafinil, which were developed as treatments, are increasingly being used by healthy people. Modafinil not only affects 'cold' cognition, but also improves 'hot' cognition, such as emotion recognition and task-related motivation. The lifestyle use of 'smart drugs' raises both safety concerns as well as ethical issues, including coercion and increasing disparity in society. As a society, we need to consider which forms of cognitive enhancement (e.g. pharmacological, exercise, lifelong learning) are acceptable and for which groups (e.g. military, doctors) under what conditions (e.g. war, shift work) and by what methods we would wish to improve and flourish.

Comorbidities of Attention Deficit Hyperactivity Disorder: Pregnancy Risk Factors and Parent Mental Health

Our study examined the risk of maternal smoking and alcohol consumption in pregnancy associated with child comorbidity in a community sample of children diagnosed with attention deficit hyperactivity disorder (ADHD). We used a cross sectional community retrospective questionnaire of 321 children diagnosed with ADHD. Our results suggest that maternal smoking increased the risk of oppositional defiant behavior (ODB) in children with ADHD twofold (OR 2.27; CI 1.29-4.11). Maternal alcohol consumption increased the risk although not significantly for ADHD child comorbid ODB, anxiety disorder and depression. Parent mental health significantly impacted on child comorbidity. Our study suggests that smoking in pregnancy is associated with comorbid ODB, independent of parent mental health, family history of ADHD and socioeconomic factors. Parent mental health is independently associated with comorbid ODB, anxiety disorder and depression.