A Pilot Twin Study of Psychological Measures of Attention Deficit Hyperactivity Disorder Association and linkage of alpha-2A adrenergic receptor gene polymorphisms with childhood ADHD. Clinical symptoms and performance on the continuous performance test in children with attention deficit hyperactivity disorder between subtypes: a natural follow-up study for 6 months Dissecting the attention deficit hyperactivity disorder (ADHD) phenotype: Sustained attention, response variability and spatial attentional asymmetries in relation to dopamine transporter (DAT1) genotype Transmission disequilibrium of polymorphic variants in the tryptophan hydroxylase-2 gene in attention-deficit/hyperactivity disorder Using a Virtual Classroom environment to describe the attention deficits profile of children with Neurofibromatosis type 1. Mediators of Methylphenidate Effects on Math Performance in Children with Attention-Deficit Hyperactivity Disorder Enhancing Behavioral and Social Skill Functioning in Children Newly Diagnosed with Attention-Deficit Hyperactivity Disorder in a Pediatric Setting Responsiveness of children with attention deficit-hyperactivity disorder to reward and response cost: differential impact on performance and motivation. The Link Between Health-Related Quality of Life and Clinical Symptoms Among Children with Attention-Deficit Hyperactivity Disorder Moderators and mediators of treatment response for children with attention-deficit/hyperactivity disorder: the Multimodal Treatment Study of children with Attention-deficit/hyperactivity disorder. Efficacy of methylphenidate in children with attention-deficit hyperactivity disorder and learning disabilities: a randomized crossover trial. PREVALENCE ESTIMATIONS OF ATTENTION-DEFICIT/HYPERACTIVITY DISORDER: DIFFERENTIAL DIAGNOSES AND COMORBIDITIES IN A COLOMBIAN SAMPLE A longitudinal examination of neuropsychological and clinical functioning in boys with attention deficit hyperactivity disorder (ADHD): improvements in executive functioning do not explain clinical improvement. Absence of the 7‐repeat variant of the DRD4 VNTR is associated with drifting sustained attention in children with ADHD but not in controls Adult outcome of attention-deficit/hyperactivity disorder: a controlled 16-year follow-up study. Clinical evaluation of subjective and objective changes in motor activity and attention in children with attention-deficit/hyperactivity disorder in a double-blind methylphenidate trial.
There has been much interest in the genetics of attention deficit hyperactivity disorder and molecular genetic studies are now underway . The success of genetic studies will depend on how well the phenotype is defined . Twin studies using parent and teacher rated question naires or interviews all appear to yield highly heritable measures . Nevertheless , there is evidence to suggest that parent measures are subject to rater bias . Consequently there has been much interest in obtaining more objective measures of related traits such as attention span and impulsiveness using , computerised neuropsychological tasks . However there have been few twin studies examining the genetic contribution to these neuropsychological measures . The present study aims to investigate whether performance on the  Matching Familiar Figures Test ( MFFT ) and Continuous Performance Task ( CPT )  is genetically influenced in childhood . 20 monozygotic ( MZ ) and 20 dizygotic ( DZ ) twin pairs were r and omly selected from the Greater Manchester Twin Register . Preliminary data suggest that MZ twins perform more similarly than DZ twins on the MFFT , but not the CPT . Future work needs to examine whether other neuropsychological measures commonly used in research on ADHD are genetically influenced using larger twin sample Attention-deficit hyperactivity disorder ( ADHD ) is a heritable disorder , prevalent from childhood through adulthood . Although the noradrenergic ( NA ) system is thought to mediate a portion of the pathophysiology of ADHD , genes in this pathway have not been investigated as frequently as those in the dopaminergic system . Previous association studies of one c and i date gene in the NA system , ADRA2A , showed inconsistent results with regard to an MspI polymorphism . In the current study , two nearby single-nucleotide polymorphisms , which define HhaI and DraI restriction fragment length polymorphisms , were also genotyped and were in significant linkage disequilibrium with the MspI RFLP . Transmission disequilibrium tests ( TDTs ) in a sample of 177 nuclear families showed significant association and linkage of the DraI polymorphism with the ADHD combined subtype ( P=0.03 ) , and the quantitative TDT showed association of this polymorphism with the inattentive ( P=0.003 ) and hyperactive-impulsive ( P=0.015 ) symptom dimensions . The haplotype that contained the less common allele of the DraI polymorphism likewise showed a strong relationship with the inattentive ( P=0.001 ) and hyperactive-impulsive ( P=0.004 ) symptom dimensions . This study supports the hypothesis that an allele of the ADRA2A gene is associated and linked with the ADHD combined subtype and suggests that the DraI polymorphism of ADRA2A is linked to a causative polymorphism Background The aims of this study were to determine the time course of improvements in attention deficit hyperactivity disorder ( ADHD ) clinical symptoms and neurocognitive function in a realistic clinical setting , and the differences in ADHD symptom improvement using different classifications of ADHD subtypes . Methods The Child Behavior Checklist ( CBCL ) was completed by parents of ADHD children at the initial visit . The  computerized Continuous Performance Test ( CPT ) , Swanson , Nolan , and Pelham , and Version IV Scale for ADHD ( SNAP-IV ) , and  ADHD Rating Scale ( ADHD-RS ) were performed at baseline , one month , three months , and six months later , respectively . Patient care including drug therapy was performed at the discretion of the psychiatrist . The ADHD patients were divided into DSM-IV subtypes ( Inattentive , Hyperactive-impulsive and Combined type ) , and were additionally categorized into aggressive and non-aggressive subtypes by aggression scale in CBCL for comparisons . Results There were 50 ADHD patients with a mean age of 7.84 ± 1.64 years ; 15 of them were inattentive type , 11 were hyperactive-impulsive type , and 24 were combined type . In addition , 28 of the ADHD patients were grouped into aggressive and 22 into non-aggressive subtypes . There were significant improvements in clinical symptoms of hyperactivity and inattention , and impulsivity performance in CPT during the 6-month treatment . The clinical hyperactive symptoms were significantly different between ADHD patients sub-grouping both by DSM-IV and aggression . Non-aggressive patients had significantly greater changes in distraction and impulsivity performances in CPT from baseline to month 6 than aggressive patients . Conclusions We found that ADHD symptoms , which included impulsive performances in CPT and clinical inattention and hyperactivity dimensions , had improved significantly over 6 months under pragmatic treatments . The non-aggressive ADHD patients might have a higher potential for improving in CPT performance than aggressive ones . However , it warrant further investigation whether the different classifications of ADHD patients could be valid for predicting the improvements in ADHD patients ' clinical symptoms and neurocognitive performance ADHD is a childhood-onset behavioural disorder with a heterogeneous profile of neuropsychological impairment . Neuropsychological heterogeneity may , in part , reflect underlying genetic differences . Here we examined sustained attention , response variability and spatial attentional asymmetries in a sample of children and adolescents with ADHD ( n=22 ) in relation to dopamine transporter genotype ( DAT1 ) and also controls ( n=20 ) . Participants performed the sustained attention to response task ( SART ) ( testing sustained attention and response variability ) and the greyscales task ( a perceptual measure of attentional bias ) . The latter has previously been shown to yield a robust leftward attentional asymmetry in healthy subjects . The 10-repeat allele of the DAT1 gene has been associated with ADHD in a number of studies and appears to have biological significance . The ADHD group was sub-divided into those individuals with two copies of the " high-risk " 10-repeat allele ( high-risk DAT1 ) versus those with one or no copies of this allele ( low-risk DAT1 ) . The high-risk DAT1 ADHD group displayed greater response variability on the SART than either the low-risk DAT1 group or healthy controls , whereas the latter two groups did not differ . Further , the high-risk DAT1 group showed an attenuated spatial asymmetry , relative to the low-risk DAT1 ADHD group , who showed the typical leftward attentional asymmetry . Our results suggest that the 10-repeat DAT1 allele may mediate neuropsychological impairment in ADHD . The application of molecular genetics may help to define neuropsychological impaired subgroups of ADHD Attention-deficit/hyperactivity disorder ( ADHD ) is the most common behavioral disorder in childhood with substantial heritability . Pharmacological and molecular genetic studies as well as characterization of animal models have implicated serotonergic dysfunction in the pathophysiology of ADHD . Here , we investigated the effect of polymorphic variants in the gene of the tryptophan hydroxylase-2 ( TPH2 ) , the rate-limiting enzyme of serotonin ( 5-HT ) synthesis in the brain , in children and adolescents with ADHD . We analyzed three single nucleotide polymorphisms ( SNPs ) in and downstream of the transcriptional control region of the TPH2 gene in 103 families with 225 affected children .  Allelic association in families with more than one affected child was assessed using the pedigree disequilibrium test . Preferential transmissions were detected for the two SNPs in TPH2 's regulatory region ( rs4570625 , P=0.049 ; rs11178997 , P=0.034 ) , but not for the third SNP in intron 2 ( rs4565946 , P=0.3517 ) . Haplotype analysis revealed a strong trend of association between the regulatory region SNPs ( rs4570625 , rs11178997 ) and ADHD ( P=0.064 ) . Our results link potentially functional TPH2 variations to the pathophysiology of ADHD , and further support the relevance of 5-HT in disorders related to altered motor activity and cognitive processes The objectives of this study were to describe the nature of the attention deficits in children with Neurofibromatosis type 1 ( NF1 ) in comparison with typically developing ( TD ) children , using the Virtual Classroom ( VC ) , and to assess the utility of this instrument for detecting attention deficits . Twenty-nine NF1 children and 25 age- and gender-matched controls , aged 8 - 16 , were assessed in a VC . Parents ' ratings on the  Conners ' Parent Rating Scales-Revised : Long ( CPRS-R : L ) question naire were used to screen for Attention Deficit-Hyperactivity Disorder ( ADHD ) . Significant differences were found between the NF1 and the control groups on the number of targets correctly identified ( omission errors ) and the number of commissions ( commission errors ) in the VC , with poorer performance by the NF1 children ( p < 0.005 ) . Significant correlations were obtained between the number of targets correctly identified , the number of commission errors , and the reaction time . Significant correlations were also found between the total correct hits and the cognitive problems/inattention scale , as well as two other indexes of the CPRS-R : L : the DSM-IV Symptoms Subscale and the ADHD Index . The VC results support the hypothesis that NF1 is marked by inattention and impulsivity and that participants with NF1 are more inattentive ( omission errors ) and impulsive ( commission errors ) than normal controls . The VC appears to be a sensitive and ecologically valid assessment tool for use in the diagnosis of attention deficits among children with NF1 Objective : Stimulant medications , such as methylpheni date ( MPH ) , improve the academic performance of children with attention-deficit hyperactivity disorder ( ADHD ) . However , the mechanism by which MPH exerts an effect on academic performance is unclear . We examined MPH effects on math performance and investigated possible mediation of MPH effects by changes in time on-task , inhibitory control , selective attention , and reaction time variability . Methods : Children with ADHD aged 7 to 11 years ( N = 93 ) completed a timed math worksheet ( with problems tailored to each individual 's level of proficiency ) and 2 neuropsychological tasks ( Go/No-Go and Child Attention Network Test ) at baseline , then participated in a 4-week , r and omized , controlled , titration trial of MPH . Children were then r and omly assigned to their optimal MPH dose or placebo for 1 week ( administered double-blind ) and repeated the math and neuropsychological tasks ( posttest ) . Baseline and posttest videorecordings of children performing the math task were coded to assess time on-task . Results : Children taking MPH completed 23 more math problems at posttest compared to baseline , whereas the placebo group completed 24 fewer problems on posttest versus baseline , but the effects on math accuracy ( percent correct ) did not differ . Path analyses revealed that only change in time on-task was a significant mediator of MPH 's improvements in math productivity . Conclusions : MPH-derived  math productivity improvements may be explained in part by increased time spent on-task , rather than improvements in neurocognitive parameters , such as inhibitory control , selective attention , or reaction time variability ABSTRACT . The objective of this study was to evaluate the effectiveness of an 8-week behavioral and social skill ( BSS ) class for children newly diagnosed with attention-deficit hyperactivity disorder ( ADHD ) and their parents , initiating stimulant treatment in primary care . The subjects were 100 children , aged 5 to 12 years , recently diagnosed with ADHD and treated with stimulant medication , and their parents or guardians . Eligible families were r and omly assigned to an intervention group ( IG : n = 59 ) or control group ( CG : n = 41 ) . The BSS function of each child was assessed using DuPaul ’s ADHD Parent Rating Scale ( 18-item ) and Child Attention Profile ( 12-item ) during blinded baseline and follow-up interviews . Parent discipline practice was assessed using a five-item inventory based on Likert-scale ratings during identical periods . Computerized pharmacy records were used to track psychostimulant use over time . IG children exhibited significantly lower parent-rated ADHD symptoms , whereas IG parents reported significantly better and more consistent discipline practice s compared with CG parents across time . No significant differences were found between groups in Child Attention Profile scores across time . Psychostimulant use did not significantly differ between groups across time .  BSS training  was well accepted and seemed to significantly improve BSS functioning among IG children in the home setting only Using a within-subject design and both high- and low-interest tasks , this study examined the effects of reward ( R ) , response cost ( RC ) , and no contingency ( NR ) on performance and motivation of 22 children with attention deficit-hyperactivity disorder ( ADHD ) and 22 controls . Dependent variables included performance measures , self-rated performance and motivation , and a new measure of behavioral motivation based on a 2-min postcontingency task .  Both contingencies benefited some aspects of the performance of ADHD children ; relative to R , RC showed stronger effects but at the expense of decreased self-rated motivation on the low-interest task . The performance of controls did not differ across tasks , whereas ADHD children performed relatively better on the high-interest task . Neither contingency decreased motivation measures relative to NR for either group . For ADHD children , motivational effects appeared to be influenced by self-perceptions of performance ABSTRACT . Clinical research on attention-deficit hyperactivity disorder ( ADHD ) has begun to integrate measures of health-related quality of life ( HRQL ) as part of the overall assessment of treatment outcomes . This study examines the association between HRQL and measures of clinical symptoms of ADHD . Data were gathered from 297 children and adolescents in an 8-week , r and omized , double-blind , placebo-controlled , clinical trial of atomoxetine treatment for ADHD . HRQL was assessed with the Child Health Question naire 50-item Parent Form . ADHD symptoms were assessed with the ADHD Rating Scale-IV ; Parent Version and Clinical Global Impressions-ADHD-Severity . Associations between HRQL and clinical symptoms were assessed with correlations , analyses of variance with post hoc comparisons , and t tests . The Child Health Question naire 50-item Parent Form scales assessing psychosocial domains of HRQL were significantly negatively correlated with clinical measures . Improvement in clinical symptoms was associated with corresponding improvement in psychosocial aspects of HRQL . The findings suggest that HRQL instruments can add important information to efficacy measures in clinical trials of ADHD treatment BACKGROUND Intent-to-treat analyses of the study revealed that medication management , alone or combined with intensive behavioral treatment , was superior to behavioral treatment and community care in reducing attention-deficit/hyperactivity disorder ( ADHD ) symptoms ; but only combined treatment showed consistently greater benefit than community care across other outcome domains ( disruptive and internalizing symptoms , achievement , parent-child relations , and social skills ) . We examine response patterns in subgroups defined by baseline variables ( moderators ) or variables related to treatment implementation ( mediators ) . METHODS We reconducted r and om-effects regression ( RR ) analyses , adding factors defined by moderators ( sex ,  prior medication use  ,  comorbid disruptive or anxiety disorder  , and public assistance ) and a mediator ( treatment acceptance/attendance ) . RESULTS Study outcomes ( N = 579 ) were upheld in most moderator subgroups ( boys and girls , children with and without prior medication , children with and without comorbid disruptive disorders ) . Comorbid anxiety disorder did moderate outcome ; in participants without anxiety , results paralleled intent-to-treat findings . For those with anxiety disorders , however , behavioral treatment yielded significantly better outcomes than community care ( and was no longer statistically different from medication management and combined treatment ) regarding ADHD-related and internalizing symptoms . In families receiving public assistance , medication management yielded decreased closeness in parent-child interactions , and combined treatment yielded relatively greater benefits for teacher-reported social skills . In families with high treatment acceptance/attendance , intent-to-treat results were upheld . Acceptance/attendance was particularly important for medication treatments . Finally , two thirds of children given community care received stimulants . Behavioral treatment did not significantly differ from , but medication management was superior to , this subgroup . CONCLUSIONS Exploratory analyses revealed that our study ( the Multimodal Treatment Study of Children With Attention-Deficit/Hyperactivity Disorder [ MTA ] ) results were confirmed across most baseline variables and treatment acceptance/attendance . In children with ADHD plus anxiety , behavioral treatment surpassed community care and approached medication-based treatments regarding parent-reported ADHD symptoms OBJECTIVE To determine whether children with attention-deficit hyperactivity disorder ( ADHD ) and learning disabilities respond differently to methylpheni date ( MPH ) compared with children with ADHD only . METHODS We conducted a prospect i ve , double-blind , placebo-controlled , r and omized , 2-week crossover trial of MPH , during which response to MPH was assessed . Learning ability was appraised using the Wide Range Achievement Test , Revised ( WRAT-R ) , for English-speaking students and the Test de rendement pour francophones for French-speaking students . The study was conducted at the Douglas Hospital , a McGill University-affiliated teaching hospital in Montréal . Ninety-five children , aged 6 - 12 years , who met the Diagnostic and Statistical Manual of Mental Disorders , fourth edition ( DSM-IV ) , criteria for ADHD participated in the study , which ran from 2001 to 2004 . The outcome measure used was the Consensus Clinical Response , an indicator of the degree of clinical improvement shown when taking MPH . RESULTS The proportion of children with learning disabilities who responded to MPH ( 55 % ) was significantly smaller ( chi(2)1 = 4.5 , p = 0.034 ) than the proportion of children without learning disabilities who responded adequately to MPH ( 75 % ) . This difference was mainly because of children with mathematics disability being particularly unresponsive to MPH ( chi(2)1 = 4.5 , p = 0.034 ) . Children with reading disability did not show this pattern of poor response ( chi(2)1 = 1.0 , p = 0.33 ) . CONCLUSION Children with ADHD and comorbid learning disability tended to respond more poorly to MPH . In particular , children with disability in mathematics responded less to MPH than those without disability in mathematics . Additional therapy may be indicated for this group of patients The aim of this article was to analyze the prevalence of Attention Deficit/ Hyperactivity Disorder ( ADHD ) in Colombian Paisa children and adolescents . A r and omized sample of 4- to 17-year-old children and adolescents--176 males and 154 females -- was selected from schools in Manizales , Colombia . The diagnosis of ADHD was obtained using a semistructured psychiatric and neurological interview , medical histories revision , and neurological or psychiatric evaluations .  Several rating scales and a neuropsychological assessment  were administered in order to confirm the diagnosis . Children with Full Scale Intelligence Quotient ( FSIQ ) between 71 and 84 were recorded as having Borderline Intellectual Functioning ( BIF ) , and those with a history of mild motor retardation , and /or Performance Intelligence Quotient ( PIQ ) lower than 71 , were recorded as having a Developmental Coordination disorder ( DCD ) , after confirmation by neurological and neuropsychological examinations . BIF and DCD children were excluded from the ADHD group . Total prevalence of ADHD adjusted by sex was 16.4 % ( males 19.8 % and females 12.3 % ) . Prevalence of clean ADHD cases was 11.5 % , distrib uted as follows : combined type , 6.4 % ; inattentive , 4.8 % ; and hyperactive-impulsive , 0.3 % . Distribution by sex was as follows : males , 14.8 % ; and females , 7.7 % ; with an odds ratio of 2.1 ( 95 % CI : 1 - 4.5 , h 2 = 4.0 , p < . 05 ) . Clean prevalence of ADHD adjusted by equal sex distribution was 11.3 % . Prevalence of BIF was 5.8 % , DCD 3.0 % , and mild mental retardation 3.9 % . Prevalence of ADHD did not show differences by socioeconomic status ( SES ) , in contrast to mild mental retardation in which BIF and DCD were significantly more frequent in the lower SES BACKGROUND Attention deficit hyperactivity disorder ( ADHD ) often , but not always , persists into adulthood . Investigations of the associations between clinical and biological markers of persistence can shed light on causal pathways . It has been proposed that compensatory improvements in executive neuropsychological functioning are associated with clinical improvements . This is the first study to test this hypothesis prospect ively . METHOD The clinical and neuropsychological functioning of 17 boys with ADHD ( mean age 10.45 years at time 1 ; 14.65 years at time 2 ) and 17 typically developing ( TYP ) boys ( mean age 10.39 years at time 1 ; 14.47 years at time 2 ) was tested on two occasions , 4 years apart . This was done using a battery of st and ardized neuropsychological tests that included tasks with high and low executive dem and s. RESULTS Clinical improvements were observed over time . Neuropsychological performance improvements were also evident , with ADHD boys developing with a similar pattern to TYP boys , but with a developmental lag . Whilst there was an association between reduced symptoms and superior performance at retest for one task with a high executive dem and ( spatial working memory ) , this was not seen with two further high executive dem and tasks [ Stockings of Cambridge and intra-dimensional extra-dimensional ( ID/ED ) set shifting ] . Also , there was no association between change in executive functioning and change in symptoms . Baseline performance on the ID/ED set-shifting task predicted better clinical outcome . Only change in performance on the low executive dem and delayed matching-to- sample task predicted better clinical outcome . CONCLUSIONS These data highlight the importance of longitudinal measurements of cognition , symptoms and treatment response over time in children and adolescents with ADHD Many genetic studies have demonstrated an association between the 7‐repeat ( 7r ) allele of a 48‐base pair variable number of t and em repeats ( VNTR ) in exon 3 of the DRD4 gene and the phenotype of attention deficit hyperactivity disorder ( ADHD ) . Previous studies have shown inconsistent associations between the 7r allele and neurocognitive performance in children with ADHD . We investigated the performance of 128 children with and without ADHD on the Fixed and R and om versions of the Sustained Attention to Response Task ( SART ) . We employed time‐series analyses of reaction‐time data to allow a fine‐grained analysis of reaction time variability , a c and i date endophenotype for ADHD . Children were grouped into either the 7r‐present group ( possessing at least one copy of the 7r allele ) or the 7r‐absent group . The ADHD group made significantly more commission errors and was significantly more variable in RT in terms of fast moment‐to‐moment variability than the control group , but no effect of genotype was found on these measures . Children with ADHD without the 7r allele made significantly more omission errors , were significantly more variable in the slow frequency domain and showed less sensitivity to the signal ( d ' ) than those children with ADHD the 7r and control children with or without the 7r . These results highlight the utility of time‐series analyses of reaction time data for delineating the neuropsychological deficits associated with ADHD and the DRD4 VNTR . Absence of the 7‐repeat allele in children with ADHD is associated with a neurocognitive profile of drifting sustained attention that gives rise to variable and inconsistent performance . © 2008 Wiley‐Liss , OBJECTIVE To estimate the risks for psychopathology and functional impairments in adulthood among a longitudinal sample of youth with and without attention-deficit/hyperactivity disorder ( ADHD ) diagnosed in childhood . METHOD This was a case-controlled , 16-year ( 15 - 19 years ) prospect i ve follow-up study of ADHD . 140 boys with and 120 without DSM-III-R ADHD were recruited from pediatric and psychiatric setting s. The main outcome measures were  structured diagnostic interviews and measures of psychosocial , educational , and neuropsychological functioning . Data were collected from 1988 to 2006 . RESULTS At the 16-year follow-up , subjects with ADHD continued to significantly differ from controls in lifetime rates of antisocial , mood , anxiety , and addictive disorders , but with the exception of a higher interval prevalence of anxiety disorders ( 20 % vs 8 % ; z = 2.32 , P = .02 ) and smoking dependence ( 27 % vs 11 % ; z = 2.30 , P = .02 ) , the incidence of individual disorders in the 6-year interval between the current and prior follow-up did not differ significantly from controls . At follow-up , the ADHD subjects compared with controls were significantly ( P < .05 ) more impaired in psychosocial , educational , and neuropsychological functioning , differences that could not be accounted for by other active psychopathology . CONCLUSIONS These long-term prospect i ve findings provide further evidence for the high morbidity associated with ADHD across the life cycle , stressing the importance of early recognition of this disorder for prevention and early intervention strategies . These findings also indicate that , in adulthood , ADHD confers significant risks for impairment that can not be accounted for by other psychopathology The aim of this study was to determine drug-dependent effects on attention and motor activity in children with attention-deficit/hyperactivity disorder ( ADHD ) in a double-blind methylpheni date ( MPH ) trial using both subjective behavior ratings and objective measures of function . In particular , we were interested in the relationship between changes of those subjective and objective measures . A total of 44 ADHD children with the combined subtype completed a r and omized , double-blind , placebo-controlled , crossover trial with 2 doses of MPH ( 0.25 ; 0.5 mg/kg body weight ) and placebo . In each condition , computerized attention tasks were performed , teacher-behavior ratings were obtained , and actigraph data were collected in both clinical and naturalistic setting s. Trend tests revealed linear effects of MPH dose on actigraph data in the test session ( p = 0.02 ) and at school ( p = 0.001 ) , as well as on sustained attention ( p < 0.001 ) , while inhibitory control showed a quadratic dose-response curve ( p < 0.001 ) . Multivariate regression analyses revealed that changes of both , hyperactive-impulsive symptoms ( 28 % ) and inattentive symptoms ( 23 % ) could be explained by objective changes of motor activity . Thus , for clinical practice , it should be taken into account that behavior ratings of ADHD symptoms seemed to be predominantly influenced by changes of motor activity
Taken together , the studies pointed at substantial evidence for a negative association between ADHD symptoms and mathematical ability .
This association was particularly marked for the inattentive component of ADHD than for the hyperactive-impulsive component .
Evidence from twin studies also showed a significant genetic correlation between mathematics and ADHD , which was greater for the inattentive component of ADHD compared to the hyperactive-impulsive component .
Conclusions The differential relationship of the hyperactivity-impulsivity and inattention domains with mathematics emphasises the heterogeneity within the disorder and suggests a partially different aetiology of the two ADHD domains .
Background Several recent behavioural and behavioural genetic studies have investigated the relationship between attention deficit hyperactivity disorder ( ADHD ) and mathematical ability .
The aim of this systematic review was to provide an overview of these studies to date .
An emphasis was placed on review ing results that explored the association between mathematics and the two ADHD components of attention and hyperactivity-impulsivity separately .