Attention-deficit/hyperactivity Disorder Research Research Articles

Child and adolescent psychiatry as a clinical neuroscience

When Andreas Warnke was invited in 2001 by Peter Riederer to become the first field editor of ‘‘Biological Child and Adolescent Psychiatry’’ in this journal, our discipline had only just begun to define itself as a clinical neuroscience. However, Peter Riederer made an excellent choice. Andreas Warnke was one of the first German chair holders of Child and Adolescent Psychiatry who pursued biological research in human mental processes. Together with his mentor Helmut Remschmidt he had understood that the basic sciences of psychiatry had to include genetics, neuroimaging, neurochemistry, and neurophysiology. He also realized that research of the developing brain would be a unique source for a better understanding of cause and pathophysiology of mental disorders in general. Consequently, he is one of the editors of the first German handbook on ‘‘Developmental Psychiatry’’. In 1993, he inaugurated the ‘‘National Conference of Biological Child and Adolescent Psychiatry’’ in Wurzburg, which nowadays takes place every year at a different site. For the last time Andreas Warnke was the president of this conference in December 2009. For his merits in ‘‘Biological Child and Adolescent Psychiatry’’ he was awarded the ‘‘Heinrich Hoffmann-Medal’’, which is the highest scientific and political reward of the German Scientific Society for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy. Biological developmental child and adolescent psychiatry is engaged in exploring vulnerability genes in complex mental disorders like autism and schizophrenia. With the help of Andreas Warnke, this journal has been an important platform to publish major findings in child and adolescent psychiatric genetics. However, the development of mental processes is far more than the expression of a genetic liability. The preeminent question is how the brain gives rise to various mental processes (Kandel 1998). In human beings genetic disposition interacts with social environment. A certain psychosocial experience may have lasting effects on behavior by changes of gene expression, a process which is called epigenetic. Special proteins may help to identify such processes in the brain—the field of proteoand metabolomics. A. Warnke was the first to support this kind of research in German child and adolescent psychiatry, which in future might lead to early detection and probably prevention of major mental disorders (Insel and Quirion 2005). His co-workers in Wurzburg further engage in neuroimaging and neurophysiology, which are major research areas represented in this journal. However, Andreas Warnke never denied the importance of interpersonal relationship in the etiology, but also the treatment of psychiatric diseases in childhood. He was always absolutely convinced that evidence-based psychotherapeutic approaches would be a major resource for a good outcome in child and adolescent mental illness. Probably, it is only a matter of time till we understand the biological processes in the brain underlying a successful psychotherapy. The main research interests of A. Warnke were dyslexia, where he is integrated in several European research projects and attention deficit/hyperactivity disorder (ADHD). To foster research in ADHD, he organized two international congresses together with Manfred Gerlach in Wurzburg and Vienna. He is the principal investigator of a huge project of the German Ministry of Education and Research to investigate the effect of mother’s ADHD on B. Herpertz-Dahlmann (&) Klinik fur Kinderund Jugendpsychiatrie und -psychotherapie, Universitatsklinikum Aachen, Neuenhofer Weg 21, 52074 Aachen, Germany e-mail: bherpertz-dahlmann@ukaachen.de

The search for biomarkers for attention deficit/hyperactivity disorder

The main characteristic of attention deficit/hyperactivity disorder (ADHD) is a persistent pattern of inattention and/or hyperactivity-impulsivity which is more frequent and severe than is usually expected in individuals at a comparable level of development. ADHD is estimated to affect approximately 5.29% of school-aged children and is therefore the most common childhood onset psychological disorder. A conservative estimate of the annual societal cost of illness for ADHD in childhood and adolescence is USD 42.5 billion in the U.S. alone. Global sales of ADHD medicines could reach USD 4.3 billion by 2012. Despite the prevalence, high heritability and costs of ADHD, biological markers do not exist. Such biomarkers are in high demand as they would help eliminate the subjective diagnoses based on interviews and potentially allow for earlier diagnosis and personalized medicine. Lack of markers likely stems from several factors that complicate ADHD research and the assessment of pharmacological responses. This review analyses complicating factors in defining ADHD phenotype and etiology, identifying specific diagnostic markers and the difficulties in the assessment of pharmacogenomic markers. The dopamine transporter (DAT1) genotype and methylphenidate (MPH) response are detailed as an example of a biomarker. A recent report of a novel ADHD gene and its possible role as a biomarker is explored. Finally, suggestions for strategies and study designs for future research for the definition of effective ADHD biomarkers are made.

Ever Increasing Number of the Animal Model Systems for Attention Deficit/Hyperactivity Disorder: Attention, Please

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by hyperactivity, inattention, and impulsiveness. Current estimates suggest that 4-12% of school age children are affected by ADHD, which hampers proper social relationship and achievements in school. Even though the exact etiology of the disorder is still in the middle of active investigation, the availability of pharmacological treatments for the disorder suggest that at least the symptoms of ADHD are manageable. To develop drugs with higher efficacy and fewer side effects, it is essential to have appropriate animal models for in vivo drug screening processes. Good animal models can also provide the chances to improve our understanding of the disease processes as well as the underlying etiology of the disorder. In this review, we summarized current animal models used for ADHD research and discussed the point of concerns about using specific animal models.

Neuropsychological measures probably facilitate heritability research of ADHD

Previous studies, in which cognitive and motor neuropsychological tasks were administered to 816 children from Attention-Deficit/Hyperactivity Disorder (ADHD)- and control-families, showed that various of these measures appeared useful for genetic research in ADHD by forming candidate endophenotypes: underlying, heritable, vulnerability traits that mark an enhanced liability for developing ADHD. The current study extends these findings by showing that six of these ten measures correlate more strongly between siblings than an ADHD composite, suggesting these measures may have a larger heritability than ADHD itself. Significant sibling cross-correlations also suggested that six of ten neuropsychological measures related to similar familial (and heritable) factors as ADHD, suggesting these measures to be useful for ADHD genetic research. An aggregated neuropsychological composite appeared to be the most powerful, since it correlated more strongly between siblings than most individual task measures. These findings suggest heritability research in ADHD will probably be facilitated by including neuropsychological measures.

DSM‐IV combined type ADHD shows familial association with sibling trait scores: A sampling strategy for QTL linkage

Attention deficit hyperactivity disorder (ADHD) is a discrete clinical syndrome characterized by the triad of inattention, hyperactivity, and impulsivity in the context of marked impairments. Molecular genetic studies have been successful in identifying genetic variants associated with ADHD, particularly with DSM-IV inattentive and combined subtypes. Quantitative trait locus (QTL) approaches to linkage and association mapping have yet to be widely used in ADHD research, although twin studies investigating individual differences suggest that genetic liability for ADHD is continuously distributed throughout the population, underscoring the applicability of quantitative dimensional approaches. To investigate the appropriateness of QTL approaches, we tested the familial association between 894 probands with a research diagnosis of DSM-IV ADHD combined type and continuous trait measures among 1,135 of their siblings unselected for phenotype. The sibling recurrence rate for ADHD combined subtype was 12.7%, yielding a sibling recurrence risk ratio (lambda(sib)) of 9.0. Estimated sibling correlations around 0.2-0.3 are similar to those estimated from the analysis of fraternal twins in population twin samples. We further show that there are no threshold effects on the sibling risk for ADHD among the ADHD probands; and that both affected and unaffected siblings contributed to the association with ADHD trait scores. In conclusion, these data confirm the main requirement for QTL mapping of ADHD by demonstrating that narrowly defined DSM-IV combined type probands show familial association with dimensional ADHD symptom scores amongst their siblings.

Using the International Classification of Functioning, Disease and Health in Attention-Deficit/Hyperactivity Disorder: Separating the Disease From Its Epiphenomena

This paper discusses the description of attention-deficit/hyperactivity disorder (ADHD) as a possible "disease entity" and the "disabilities" associated with it. It builds on the nosological descriptions of ADHD from International Classification of Disease (ICD) and Diagnostic and Statistical Manual of Mental Disorders (DSM) perspectives and introduces the distinct disability dimension from the International Classification of Functioning, Disability and Health (ICF) perspective. It advocates for separating assessment of disease and disability dimensions and then utilizing these constructs jointly by using both the ICD and ICF classifications. The ICF analyzes functioning in relation to a health condition in terms of 1) body functions and body structures, 2) activities of the person and participation of the person in society, and 3) contextual factors such as environmental factors and personal factors. The separation of signs/symptoms and consequences permits better understanding of the disease pathophysiology on the one hand and the consequences (eg, its impact on the person, family, peers, school, work, and social life) on the other hand. It will therefore enable us to better understand the nature of ADHD because the core body functions associated with the disorder will be better delineated. In addition, capturing environmental factors may help people with ADHD by modifying their environments. The ICF provides a good outcome monitoring and evaluation tool for the assessment of treatment response. As in many other disorders, diagnosis alone is not a sufficient predictor of health care needs, utilization, costs, or outcomes. When one adds disability as a predictor, our capacity to predict these parameters is increased dramatically. It is therefore suggested that the ICF framework be considered in future ADHD research activities.

Adult Attention Deficit Hyperactivity Disorder: Moving Beyond DSM-IV

Adult Attention Deficit Hyperactivity Disorder: Moving Beyond DSM-IV

Innovations and recent trends in the treatment of ADHD

Initiatives to develop better-tolerated, more efficacious pharmacological agents with improved drug delivery systems have driven recent research in attention-deficit hyperactivity disorder (ADHD). While stimulants are the primary pharmacotherapy for ADHD, these drugs have a limited duration of action and a subset of patients will either fail to respond to these medications or have side effects that preclude their use. The development of atomoxetine, the first nonstimulant approved for ADHD, has been followed by additional innovative research, such as the methylphenidate transdermal system, modafinil, NRP-104 and cholinergic agents. This review highlights some of the recent trends in ADHD treatment and the current status of promising treatment options that may help to shape the future of ADHD treatment.

Sleep in children with attention-deficit hyperactivity disorder: A meta-analysis of polysomnographic studies

The links between sleep and attention-deficit hyperactivity disorder (ADHD) have been a topic for intense ongoing research and clinical interest. Previous narrative literature reviews conveyed a consensus that parents of children with ADHD are more likely to report sleep problems in their children in comparison to parents of control children. However, when objective measures are considered the results appear to be more complex and inconsistent. This review is based on a meta-analysis of relevant polysomnographic studies. We assessed measures related to sleep architecture, breathing disorders, and periodic limb movements in sleep (PLMS), and the role of potential moderators such as age, gender, and other methodological factors. The meta-analysis revealed only one significant combined effect that indicates that children with ADHD are more likely than controls to suffer from PLMS. Factors such as age, gender, inclusion of adaptation night, and comorbidity appear to play a moderating role in the associations between sleep characteristics and ADHD. To provide new insight regarding the links between sleep and ADHD research in this field should adopt new strict guidelines and consider the role of multiple pertinent moderating factors.

Parenting in mothers with and without attention-deficit/ hyperactivity disorder.

The authors examined the impact of maternal attention-deficit/hyperactivity disorder (ADHD) on parenting behaviors. Sixty mothers between the ages of 31 and 50 with (n = 30) and without (n = 30) ADHD and their 8- to 14-year-old children with ADHD completed self-report and laboratory measures of monitoring of child behavior, consistency in parenting, and parenting problem-solving abilities. These parenting behaviors were selected because of their established links to the development of child behavior problems. As predicted, mothers with ADHD were found to be poorer at monitoring child behavior and less consistent disciplinarians compared with mothers without ADHD. There was some evidence to support the prediction that mothers with ADHD were less effective at problem solving about childrearing issues than control mothers. The differences between the 2 groups of mothers persisted after child oppositional and conduct-disordered behavior were controlled. These results indicate that parenting is an area of functioning that requires more attention in adult ADHD research.

EUNETHYDIS -- searching for valid aetiological candidates of Attention-Deficit Hyperactivity Disorder or Hyperkinetic Disorder.

To step up research in ADHD, exchange of ideas, working together on key theoretical models and cooperative studies are necessary. To report about a European approach with strong links to the rest of the world. European Network on Hyperkinetic Disorders (Eunethydis) studies of Attention -- Deficit Hyperactivity Disorder (ADHD) or Hyperkinetic Disorder (HKD) is briefly reviewed in the context of the international effort to discover the aetiology of the disorder. There are promising neurobiological, neurophysiological and neuropsychological candidates to explain the nature of ADHD/HKD. Eunethydis has shown to be a fruitful platform for ADHD research and has good resources for its further development.

Genome-wide scan of reading ability in affected sibling pairs with attention-deficit/hyperactivity disorder: unique and shared genetic effects.

Attention-deficit/hyperactivity disorder (ADHD) and reading disability (RD) are common highly heritable disorders of childhood, which frequently co-occur. Data from twin and family studies suggest that this overlap is, in part, due to shared genetic underpinnings. Here, we report the first genome-wide linkage analysis of measures of reading ability in children with ADHD, using a sample of 233 affected sibling pairs who previously participated in a genome-wide scan for susceptibility loci in ADHD. Quantitative trait locus (QTL) analysis of a composite reading factor defined from three highly correlated reading measures identified suggestive linkage (multipoint maximum lod score, MLS>2.2) in four chromosomal regions. Two regions (16p, 17q) overlap those implicated by our previous genome-wide scan for ADHD in the same sample: one region (2p) provides replication for an RD susceptibility locus, and one region (10q) falls approximately 35 cM from a modestly highlighted region in an independent genome-wide scan of siblings with ADHD. Investigation of an individual reading measure of Reading Recognition supported linkage to putative RD susceptibility regions on chromosome 8p (MLS=2.4) and 15q (MLS=1.38). Thus, the data support the existence of genetic factors that have pleiotropic effects on ADHD and reading ability--as suggested by shared linkages on 16p, 17q and possibly 10q--but also those that appear to be unique to reading--as indicated by linkages on 2p, 8p and 15q that coincide with those previously found in studies of RD. Our study also suggests that reading measures may represent useful phenotypes in ADHD research. The eventual identification of genes underlying these unique and shared linkages may increase our understanding of ADHD, RD and the relationship between the two.

Assessment and treatment of attention deficit hyperactivity disorder in children with comorbid psychiatric illness

Attention deficit hyperactivity disorder (ADHD) frequently occurs with a wide variety of comorbid psychiatric disorders such as conduct disorder, depression, mania, anxiety, and learning disabilities. Because the vast majority of children with ADHD are treated in primary care settings, it is important that primary medical doctors be proficient in the diagnosis and initial treatment of children with ADHD and its commonly occurring comorbid disorders. ADHD research is beginning to focus on the treatment of these comorbidly ill children. This review will summarize the recent findings from the psychiatric literature in an attempt to provide the clinician with some initial diagnostic and treatment guidelines for ADHD and its comorbidities. The NIMH Multimodal Treatment Study of ADHD found that children with other disruptive behavior disorders plus ADHD respond well to stimulant medications, with behavioral interventions reducing academic and social impairment. Children with anxiety and ADHD are very responsive across multiple dimensions to behavioral and pharmacological ADHD treatments. Much less is known about the impact of depression on ADHD, and significant debate exists surrounding the identification and treatment of bipolar disorder in children with ADHD. Children with learning disabilities respond well to stimulants but often require additional educational supports. New findings suggest that treating ADHD may prevent the development of future psychiatric disorders. The presence of comorbid illness is associated with significant additional morbidity and complicates the diagnosis, treatment, and prognosis of ADHD. Therefore, it is important to identify and treat any comorbid psychiatric conditions in a child with ADHD.

Time course of RCBF changes with haloperidol and olanzapine over a six week treatment period

Visuospatial working memory impairments have been implicated in the pathophysiology of attention-deficit/hyperactivity disorder (ADHD). However, most ADHD research has focused on the neural correlates of nonspatial mnemonic processes. This study examined brain activation and functional connectivity for visuospatial working memory in youth with and without ADHD.Twenty-four youth with ADHD and 21 age- and sex-matched healthy controls were scanned with functional magnetic resonance imaging while performing an N-back test of working memory for spatial position. Block-design analyses contrasted activation and functional connectivity separately for high (2-back) and low (1-back) working memory load conditions versus the control condition (0-back). The effect of working memory load was modeled with linear contrasts.The 2 groups performed comparably on the task and demonstrated similar patterns of frontoparietal activation, with no differences in linear gains in activation as working memory load increased. However, youth with ADHD showed greater activation in the left dorsolateral prefrontal cortex (DLPFC) and left posterior cingulate cortex (PCC), greater functional connectivity between the left DLPFC and left intraparietal sulcus, and reduced left DLPFC connectivity with left midcingulate cortex and PCC for the high load contrast compared to controls (p < .01; k > 100 voxels). Reanalysis using a more conservative statistical approach (p < .001; k > 100 voxels) yielded group differences in PCC activation and DLPFC-midcingulate connectivity.Youth with ADHD show decreased efficiency of DLPFC for high-load visuospatial working memory and greater reliance on posterior spatial attention circuits to store and update spatial position than healthy control youth. Findings should be replicated in larger samples.

How the special needs brain learns

List of Strategies to Consider About the Author Preface to the Second Edition Acknowledgements Introduction Who Are Special Needs Students? Can Brain Research Help? What Is in This Book? A Word of Caution 1. The Brain and Learning Some Exterior Parts of the Brain Lobes of the Brain Motor Cortex and Somatosensory Cortex Cerebellum Some Interior Parts of the Brain Brainstem Limbic Area Cerebrum Brain Cells Learning and Retention Implications for Students With Learning Disabilities Rehearsal Learning Motor Skills How Different Are the Brains of Today's Students? The Search for Novelty Have Schools Changed to Deal With This Different Brain? 2. When Learning Difficulties Arise Research Examines Learning Disabilities Possible Causes of Learning Disabilities Gender Differences What Forms of Instruction Are Most Effective? Misconceptions About Learning Disabilities Gifted Children With Learning Disabilities Responsiveness to Intervention Key Elements of Responsiveness to Intervention Helping Students Become Strategic Learners What Is Learning? Learning Difficulties of Students With Learning Disabilities What Are Learning Strategies? How Important Is Self-Esteem? 3. Attention Disorders Research Findings What Is Attention-Deficit Hyperactivity Disorder (ADHD)? What Causes ADHD? Is ADHD Inherited? IS ADHD on the Increase? Is it Possible to Have ADHD-Like Behavior and Not Have ADHD? The Future of ADHD Research and Treatment What Educators Need to Consider 4. Speech Disabilities Learning Spoken Language Is Language Prewired in the Brain? Speech and Language Patterns by Age Putting the Language Components Together Problems in Learning Spoken Language Language Problems With Children and Adolescents Language Deficits and Learning a Second Language The Future of Speech-Language Disorders Research What Educators Need to Consider 5. Reading Disabilities Learning to Read Is Reading a Natural Ability? Spoken Language and Reading Decoding and Comprehension Difficulties in Learning to Read Social and Cultural Causes of Reading Problems Physical Causes of Reading Problems Is Dyslexia Present in Readers of Other Languages? Brain Imaging Studies and Dyslexia Detecting Reading Problems Spoken Language Difficulties Early Indicators of Reading Problems What Educators Need to Consider What Teachers Should Know About Teaching Reading What Beginning Readers Need to Learn Some Effective Reading Intervention Programs 6. Writing Disabilities Learning to Write Difficulties in Writing Environmental Causes Neurological Causes Dysgraphia What Educators Need to Consider Characterisitics of Good Writing Helping Students With Dysgraphia 7. Mathematical Disabilities Learning to Calculate Numerical Reasoning Independent of Language Gender Differences in Mathematics Difficulties in Mathematics Dyscalculia The Future of Research in Mathematics Disorders What Educators Need to Consider Determining the Source of the Problem Diagnostic Tools for Assessing Learning Difficulties in Mathematics Other Considerations 8. Emotional and Behavioral Disorders Emotions, Behavior, and Learning Pathways of Emotional Signals Different Brain Areas for Different Emotions First Survival and Emotions, Then the Textbook Emotional and Behavioral Disorders Anxiety Disorders Depressive Disorders Other Emotional and Behavioral Disorders Impact of Childhood Abuse The Future of Research in Emotional and Behavioral Disorders What Educators Need to Consider 9. Autism Spectrum Disorders Pervasive Developmental Disorders Autism Spectrum Disorders The Future of Research on Autism Spectrum Disorders What Educators Need to Consider 10. Putting It All Together Helping Students With Learning Difficulties Identifying Students With Learning Difficulties Accommodating Students With Learning Difficulties Motivating Students With Learning Difficulties Communicating With Parents Glossary References Resources Index

Psychosocial Treatment Issues in the MTA: A Reply to Greene and Ablon

Discussed several of Greene and Ablon's (this issue) key points in their article about the Multimodal Treatment Study (MTA) of Children with Attention Deficit Hyperactivity Disorder (ADHD). In particular, the following issues are addressed: (a) whether the medication management and behavioral arms of the MTA individualized treatment to comparable degrees; (b) whether cognitive-behavioral interventions were incorporated to an adequate extent; (c) whether core ADHD symptoms were overemphasized relative to other functional domains, both as treatment targets and outcome measures; and (d) whether parent and teacher characteristics warranted more emphasis than they were given. These issues are discussed and an attempt is made to fit the MTA findings into the larger context of prior studies on treatment of childhood ADHD. A theme of this commentary is the concern that in the current age of biological emphasis in the field of ADHD research, social, family, and motivational processes may not get the attention they deserve.

Diversity and attention deficit hyperactivity disorder.

Attention Deficit Hyperactivity Disorder (ADHD) is a debilitating disorder which affects children and adults in this country and around the world. Diversity variables such as ethnicity, age, gender, and socioeconomic status have been relatively neglected in ADHD research. Additionally, these variables have not traditionally been incorporated into clinical assessment, diagnosis, or intervention strategies. A review of the existing literature regarding diversity issues and ADHD was conducted, including a review of international findings. Implications for clinicians and researchers are incorporated.

Diagnostic Continuity Between Child and Adolescent ADHD: Findings From a Longitudinal Clinical Sample

To determine whether there are differences in the clinical expression and correlates of attention-deficit hyperactivity disorder (ADHD) between children and adolescents. Subjects were 6- to 17-year old Caucasian, non-Hispanic boys with and without ADHD. DSM-III-R structured diagnostic interviews, psychometric measures, and blind raters assessed psychiatric diagnoses, intellectual performance, social disability, school failure, and family functioning. Children and adolescents with ADHD had an almost identical pattern of correlates in multiple domains of assessment including psychosocial adversity and comorbidity with conduct, mood, and anxiety disorders. Although the rate of substance abuse differed in comparison between child and adolescent subjects, this was independent of ADHD status. These findings document the diagnostic continuity of ADHD between childhood and adolescence and support the inclusion of adolescent samples in ADHD research protocols.

Inattentive and Hyperactive Behaviors and Driving Offenses in Adolescence

The associations between symptoms of attention-deficit hyperactivity disorder (ADHD), conduct disorder, anxiety, or depression and no disorder in relation to driving offenses were examined in 916 adolescents. Self-report and parent report were used to assess a birth cohort of New Zealand adolescents' mental health status at age 15 years. Adolescents who scored 1.5 SD above the mean on the DSM-III total ADHD symptom scale were identified as reporting significant ADHD symptomatology. Self-report data and official traffic conviction records were used to identify adolescents who had committed driving offenses between ages 15 and 18 years. ADHD symptomatology and conduct disorder were strongly associated with driving offenses. ADHD symptomatology in females was significantly associated with driving offenses and more traffic crashes compared with other disorder or no disorder. Adolescents with a history of ADHD and conduct problems are significantly more likely than their peers to commit traffic offenses. Research in ADHD and risky driving should include female adolescents, as those with attentional difficulties are at a high risk for being involved in traffic crashes than females who do not experience attentional difficulties.

Sex differences in ADHD: conference summary.

Clinical samples of attention deficit hyperactivity disorder (ADHD) have been dominated by males. Consequently, female manifestations and sex differences have been relatively neglected in the extensive ADHD research. Because ADHD is so common (3% to 5% of school children) and chronic (lifelong in many cases), even a small proportion of females multiplied by such a large base means hundreds of thousands of girls and women with ADHD, a significant public health problem. An NIMH conference concluded that research is needed not only on sex differences related to ADHD, but also on manifestations of ADHD in females as such. Areas of focus should include differences in life course (sex-differential age effects); effects of hormones; effects of ADHD parenting (in utero and postnatal) on the next generation; response to and implications for design of psychosocial treatment; effects of differential comorbidity; normative "background" sex differences that influence the manifestation of ADHD; differences in development of verbal fluency and social behavior; possible interactions of sex and ethnicity; a prospective study of both sex offspring of ADHD adults; and such methodological issues as appropriate instruments and diagnostic thresholds, power to prevent false negatives, valid impairment measures, validity and reliability of child self-reports, and more inclusive samples (all three subtypes: inattentive, hyperactive-impulsive, and combined).