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PubMed2003

Impulsivity, emotion regulation, and developmental psychopathology: specificity versus generality of linkages.

Impulsivity, closely related to the construct of response (dis)inhibition, is central to conceptions of both attention-deficit/hyperactivity (ADHD) and aggressive-spectrum or disruptive behavior disorders. The multifaceted nature of inhibitory deficits requires careful specification in any explanatory accounts of psychopathology. A host of brain regions and neural interconnections are involved in response inhibition; neural models are likely to be complex at the levels of neurotransmitter systems and white-matter tracts. Despite the substantial heritability of ADHD and the substantial continuity of early-onset forms of aggression, developmental processes (including gene-environment correlations and interactions) and transactional models are crucial to the unfolding of regulated versus dysregulated behavioral outcomes. Thus, stressful prenatal and childhood environments must be investigated with as much precision as genetic loci and neural pathways. Differentiating executive inhibition (believed to be largely dopaminergic and frontal/frontal-striatal in nature) from motivational inhibition (believed to be largely noradrenergic/serotonergic and limbic in nature) is necessary to distinguish subtypes of youth with attentional and aggressive problems, and to differentiate key etiologic processes. Indeed, the executive function deficits in children with ADHD appear to independent of their emotion dysregulation, which is specific to an aggressive subgroup. Sex differences in response inhibition and sex differences in its linkages to psychopathology are relatively unexplored. For progress in subsequent research to occur, the following are required: precision in measurement at both biological and behavioral levels; contrasts with clinical comparison samples and comorbid groups (as well as normal control samples); prospective longitudinal investigations; and attention to both developmental processes and contextual variables, including stressful life events, socialization practices, and cultural parameters.

Affect↗

PubMed2002

EEG evidence for a new conceptualisation of attention deficit hyperactivity disorder.

OBJECTIVES: This study investigated the presence of electroencephalographic (EEG) clusters within a sample of children with the inattentive type of attention-deficit/hyperactivity disorder (ADHD). METHODS: Subjects consisted of 100 boys with ADHD and 40 age-matched controls. EEG was recorded from 21 sites during an eyes-closed resting condition and Fourier transformed to provide estimates for total power, and relative power in the delta, theta, alpha and beta bands. Factor analysis was used to group sites into 3 regions; frontal, central and posterior. These data were subjected to cluster analysis. RESULTS: Two distinct EEG clusters of children with the inattentive type of ADHD were found. These were characterised by (a) increased high-amplitude theta with deficiencies of delta and beta activities, and (b) increased slow wave and deficiencies of fast wave activity. CONCLUSIONS: These two subtypes are independent of current diagnostic categories, and consist of a cortically hypoaroused group and a group typified by a maturational lag in central nervous system (CNS) development. These results support a re-conceptualisation of ADHD based on the CNS abnormality underlying the disorder rather than the behavioural profile of the child. This has the potential to add a level of predictive validity, which is currently lacking in the present diagnostic systems.

Adolescent↗

PubMed2006

The alpha(2C)-adrenergic receptor mediates hyperactivity of coloboma mice, a model of attention deficit hyperactivity disorder.

Drugs that modify noradrenergic transmission such as atomoxetine and clonidine are increasingly prescribed for the treatment of attention deficit hyperactivity disorder (ADHD). However, the therapeutic targets of these compounds are unknown. Norepinephrine is also implicated in the hyperactivity exhibited by coloboma mice. To identify the receptor subtypes that regulate the hyperactivity, coloboma mice were systematically challenged with adrenergic drugs. The beta-adrenergic receptor antagonist propranolol and the alpha(1)-adrenergic receptor antagonist prazosin each had little effect on the hyperactivity. Conversely, the alpha(2)-adrenergic receptor antagonist yohimbine reduced the activity of coloboma mice but not control mice. Subtype-selective blockade of alpha(2C)-, but not alpha(2A)- or alpha(2B)-adrenergic receptors, ameliorated hyperactivity of coloboma mice without affecting activity of control mice, suggesting that alpha(2C)-adrenergic receptors mediate the hyperactivity. Localized in the basal ganglia, alpha(2C)-adrenergic receptors are in a prime position to impact locomotor activity and are, therefore, potential targets of pharmacotherapy for ADHD.

Adrenergic alpha-Antagonists↗

PubMed2005

Molecular genetic studies of ADHD: 1991 to 2004.

Attention deficit hyperactivity disorder (ADHD)is highly heritable but is likely a complex disorder involving multiple genes of moderate effect (Smalley [1997: Am J Hum Genet 60:1276-12821]). Over 100 studies have examined the genetics of ADHD by linkage or association, though no article has presented a comprehensive overview of all published reports. We reviewed all ADHD studies, including 3 genome-wide linkage studies, and association studies of 94 polymorphisms in 33 candidate genes. To simplify comparisons across heterogeneous articles, demographics and comorbidity were ignored; analyses of subtype and haplotypes were excluded; and only the most positive finding for each polymorphism in a study was reported. Thirty-six percent of all findings were positive (P< 0.05), 17% were trends (0.05 0.15). Studies utilizing dimensional measures of ADHD tended to result in higher rates of positive findings than those using categorical diagnoses (X(2) = 5.6, P = 0.018), and case-control studies tended to result in higher rates of positive findings than family-based studies (X(2) = 18.8, P < 0.001). However, for either dichotomy, no significant difference remained when analyzing only studies using both methods within the same population and polymorphism. Evidence for association exists for four genes in ADHD: the dopamine D4 and D5 receptors, and the dopamine and serotonin transporters; others are promising but need further replication, including the dopamine D2 and serotonin 2A receptors. All candidate gene approaches continue to face the problem of relatively low power, given modest odds ratios for even the best replicated genes.

Attention Deficit Disorder with Hyperactivity↗

PubMed1991

Stage I and II subdiaphragmatic Hodgkin's disease.

From January 1971 to December 1986, 521 patients with Hodgkin's disease were evaluated and treated at the Yale University School of Medicine or one of its close affiliates. A total of 258 patients had pathologic stage (PS) I or II disease, with 239 patients having Hodgkin's disease above the diaphragm (ADHD) and 19 patients having Hodgkin's disease below the diaphragm (BDHD). A comparison of patients with BDHD versus patients with ADHD showed that patients with BDHD were older (mean age, 42 versus 28 years of age, P = 0.005), were initially seen less often with nodular sclerosis subtype (32% versus 77%, P = 0.00001), and had a higher male: female ratio (2.8 versus 1.2, P = 0.12). Ten patients with BDHD (53%) had positive findings at staging laparotomy (0 of 4 clinical stage [CS] IA patients and 10 of 15 (67%) CS II patients). Radiation therapy alone was the initial treatment of choice for 74% of patients with BDHD versus 94% of the patients with ADHD. There was no statistical difference in the overall survival or relapse-free survival rates for patients with BDHD versus ADHD (10-year survival rates, BDHD = 73% and ADHD = 81%). However, patients with BDHD who initially had intra-abdominal disease had a statistically significant increase in death rate (60%) due to Hodgkin's disease compared with patients with BDHD who initially had only peripheral nodal disease (0%). Treatment recommendations for patients with BDHD should be tailored to the specific clinical presentation of each patient. For most PS IA/IIA patients initially seen with peripheral nodal disease, radiation therapy alone is a successful treatment program. However, combined modality therapy should be the treatment of choice for patients with BDHD initially seen with intra-abdominal disease.

Abdominal Neoplasms↗

PubMed2001

Atomoxetine in the treatment of children and adolescents with attention-deficit/hyperactivity disorder: a randomized, placebo-controlled, dose-response study.

OBJECTIVE: Atomoxetine is an investigational, nonstimulant pharmacotherapy being studied as potential treatment for attention-deficit/hyperactivity disorder (ADHD). It is thought to act via blockade of the presynaptic norepinephrine transporter in the brain. We assessed the efficacy of 3 doses of atomoxetine compared with placebo in children and adolescents with ADHD. METHODS: A total of 297 children and adolescents who were 8 to 18 years of age and had ADHD as defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, were randomized to placebo or atomoxetine dosed on a weight-adjusted basis at 0.5 mg/kg/day, 1.2 mg/kg/day, or 1.8 mg/kg/day for an 8-week period. ADHD symptoms, affective symptoms, and social and family functioning were assessed using parent and investigator rating scales. RESULTS: Approximately 71% of children enrolled were male, approximately 67% met criteria for mixed subtype (both inattentive and hyperactive/impulsive symptoms), and the only common psychiatric comorbidity was oppositional defiant disorder (approximately 38% of the sample). At baseline, symptom severity was rated as moderate to severe for most children. At endpoint, atomoxetine 1.2 mg/kg/day and 1.8 mg/kg/day were consistently associated with superior outcomes in ADHD symptoms compared with placebo and were not different from each other. The dose of 0.5 mg/kg/day was associated with intermediate efficacy between placebo and the 2 higher doses, suggesting a graded dose-response. Social and family functioning also were improved in the atomoxetine groups compared with placebo with statistically significant improvements in measures of children's ability to meet psychosocial role expectations and parental impact. Discontinuations as a result of adverse events were <5% for all groups. CONCLUSION: Among children and adolescents aged 8 to 18, atomoxetine was superior to placebo in reducing ADHD symptoms and in improving social and family functioning symptoms. Atomoxetine was associated with a graded dose-response, and 1.2 mg/kg/day seems to be as effective as 1.8 mg/kg/day and is likely to be the appropriate initial target dose for most patients. Treatment with atomoxetine was safe and well tolerated.

Adolescent↗

PubMed2002

Preadolescent girls with attention-deficit/hyperactivity disorder: II. Neuropsychological performance in relation to subtypes and individual classification.

This study examined executive functions, motor speed, and language processing in a diverse, preadolescent sample of 93 girls with attention-deficit/hyperactivity disorder (ADHD) combined type, 47 ADHD inattentive type, and 88 age- and ethnicity-matched comparison girls. Testing was performed without stimulant medication. All 10 neuropsychological variables showed significant omnibus subgroup differences, with 8 of 10 combined versus comparison contrasts significant (average effect size medium) and 6 of 10 inattentive versus comparison contrasts significant (average effect size small to medium), but only 2 of 10 combined versus inattentive contrasts significant (average effect size small). Results were robust to statistical control of demographic variables, comorbidities, and IQ. Discriminant function analysis revealed relatively high sensitivity but only modest specificity in predicting ADHD from comparison status from test performance; classification of the inattentive type was extremely poor.

Attention Deficit Disorder with Hyperactivity↗

PubMed2000

The cognitive-energetic model: an empirical approach to attention-deficit hyperactivity disorder.

Attention Deficit/Hyperactivity Disorder (ADHD) is a childhood psychiatric disorder which when carefully defined, affects around 1% of the childhood population [Swanson JM, Sergeant JA, Taylor E, Sonuga-Barke EJS, Jensen PS, Canwell DP. Attention-deficit hyperactivity disorder and hyperkinetic disorder. Lancet 1998;351:429-433]. The primary symptoms: distractibility, impulsivity and overactivity vary in degree and association in such children, which led DSM IV to propose three subgroups. Only one of these subgroups, the combined subtype: deficits in all three areas, meets the ICD-10 criteria. Since the other two subtypes are used extensively in North America (but not in Europe), widely different results between centres are to be expected and have been reported. Central to the ADHD syndrome is the idea of an attention deficit. In order to investigate attention, it is necessary to define what one means by this term and to operationalize it in such a manner that others can test and replicate findings. We have advocated the use of a cognitive-energetic model [Sanders, AF. Towards a model of stress and performance. Acta Psychologica 1983;53: 61-97]. The cognitive-energetic model of ADHD approaches the ADHD deficiency at three distinct levels. First, a lower set of cognitive processes: encoding, central processing and response organisation is postulated. Study of these processes has indicated that there are no deficits of processing at encoding or central processing but are present in motor organisation [Sergeant JA, van der Meere JJ. Convergence of approaches in localizing the hyperactivity deficit. In Lahey BB, Kazdin AE, editors. Advancements in clinical child psychology, vol. 13. New York: Plenum press, 1990. p. 207-45; Sergeant, JA, van der Meere JJ. Additive factor methodology applied to psychopathology with special reference to hyperactivity. Acta Psychologica 1990;74:277-295]. A second level of the cognitive-energetic model consists of the energetic pools: arousal, activation and effort. At this level, the primary deficits of ADHD are associated with the activation pool and (to some extent) effort. The third level of the model contains a management or executive function system. Barkley [Barkley RA, Behavioral inhibition, sustained attention, and executive functions: constructing a unifying theory of ADHD. Psychological Bulletin 1997;121:65-94] reviewed the literature and concluded that executive function deficiencies were primarily due to a failure of inhibition. Oosterlaan, Logan and Sergeant [Oosterlaan J, Logan GD, Sergeant JA. Response inhibition in ADHD, CD, comorbid ADHD + CD, anxious and normal children: a meta-analysis of studies with the stop task. Journal of Child Psychology and Psychiatry 1998;39:411-426] demonstrated that this explanation was not specific to ADHD but also applied to children with the associated disorders of oppositional defiant and conduct disorder. Other executive functions seem to be intact, while others, are deficient. It is argued here that the cognitive-energetic model is a useful guide for determining not only ADHD deficiencies and associated disorders but also linking human cognitive neuroscience studies with neurobiological models of ADHD using animals [Sadile AG. Multiple evidence of a segmental defect in the anterior forebrain of an animal model of hyperactivity and attention deficits. Neuroscience and Biobehavioral Reviews, in press; Sagvolden T, Sergeant JA. Attention-deficit hyperactivity disorder: from brain dysyfunctions to behaviour. Behavioural Brain Research 1998;94:1-10]. A plea for an integrated attack on this research problem is made and the suggestion that conceptual refinement between levels of analysis is essential for further fundamental work to succeed is offered here.

Animals↗

PubMed2006

Social incompetence in children with ADHD: possible moderators and mediators in social-skills training.

Children with attention-deficit/hyperactivity disorder (ADHD) often encounter problems in social interactions with peers and are confronted with peer rejection and social isolation. The most common approach to social problems in children is social skills training. This intervention concept represents a variable mixture of cognitive-behavioral intervention elements. In this article the outcome of social skills training (SST) for children with ADHD is reviewed. Four experimental SSTs are detected and analyzed for potential mediators and moderators of treatment efficacy. Candidate mediators (social cognitive skills, parenting style and medication-induced reduction of key symptoms) are discussed within an empirical and theoretical context. Candidate moderators (subtype, comorbidity, gender and age) are evaluated for their empirical support. It is argued that, although fragmented, there is ample evidence and knowledge to adapt the SST-paradigm towards the specific needs of children suffering from ADHD and to guide future research towards more effective, "well established" interventions.

Attention Deficit Disorder with Hyperactivity↗

PubMed2004

The clinical necessity for assessing Attention Deficit/Hyperactivity Disorder (AD/HD) symptoms in children with high-functioning Pervasive Developmental Disorder (PDD).

Although the DSM-IV diagnostic criteria for Attention Deficit/Hyperactivity Disorder (AD/HD) exclude Pervasive Developmental Disorder (PDD), some clinicians find that the two disorders can be comorbid and, in fact, make a dual diagnosis. Nevertheless, few empirical studies have investigated the clinical necessity for this practice. In the first of our two studies, children with high-functioning PDD were selected from among 520 outpatients. Of these, children also meeting the DSM-IV criteria for AD/HD were identified through a psychologist's observation, the completion of the ADHD-Rating Scale by parents and/or teachers, and a child psychiatrist's examination. We then examined the impact of PDD subtype and age on the co-occurrence rate. Study 2 analyzed comorbidity in two cases taken from Study 1. Of the 53 subjects in Study 1, 36 children also met the DSM-IV criteria for AD/HD. The co-occurrence rate for Asperger's Disorder (AS)/Pervasive Developmental Disorder, Not Otherwise Specified (PDDNOS) (85%) was significantly higher than for Autistic Disorder (57.6 %), and AD/HD symptoms were more common in younger children. Study 2 demonstrated the existence of comorbidity of PDD and AD/HD as separate disorders. We conclude not only that AD/HD symptoms occur frequently in children with PDD, but also that in some cases a dual diagnosis is essential to the implementation of effective treatment.

Adolescent↗

PubMedDate not supplied

[Cocaine and other psychostimulant consumption: their relationship with the childhood hyperactivity syndrome].

INTRODUCTION: We want to know the attention deficit hyperactivity disorder (ADHD) among those subjects who require treatment due to cocaine and other psychostimulant drugs consumption. No previous Spanish studies have been found. METHODS: Two groups of male subjects were established out of a total of 109 subjects. Their ages ranged from 16 to 40 years. The groups were "experimental" (patients under treatment) and "control", who underwent a urine analysis for toxic agents. An interview elaborated for this and the E mode SCID-I were used. A total of 21 % of the cocaine consumers had a comorbid history of ADHD in childhood versus 3% of the control group. CONCLUSIONS: The data found overlap with the United States studies. ADHD appears as a new risk factor for the posterior development of cocaine abuse disorder, adding a cocaine addict patient subtype that deserves special diagnostic criteria as well as more complete treatment alternatives for these dual diagnosed patients.

Adolescent↗

PubMed2006

[Atentional processes and attention deficit disorders in autism].

INTRODUCTION: Autism is recognised as being a behavioural syndrome characterised by impaired language development, restricted interests and compromised socialisation. It is accepted that persons with autism react in an inappropriate way to socially relevant information and that they are unable to benefit from important stimuli from their surroundings. A number of disorders affecting different attention processes (with the ensuing difficulty involved in selecting and hierarchising stimuli) have been put forward as probable hypotheses to account for the genesis of these problems. DEVELOPMENT: In this work we analyse some of the attentional processes reported as being due to deficits in autism (disorders affecting alertness, orientation, gaze, sustained attention and changes in focus of attention). We also examine the high rate of comorbidity of attention deficit disorders with or without hyperactivity (ADHD) with pervasive developmental disorders (PDD) and the importance of identifying them. CONCLUSIONS: Although many disorders affecting the components of attention have been reported, the findings and their importance are controversial and it is likely that their association to other cognitive disorders plays an important role in the development of autism. With regard to the association between ADHD and PDD, it is an acknowledged fact that up to 70% of the persons with PDD meet ADHD criteria; whether we are before a situation of comorbidity, it is part of the spectrum or forms a specific subtype is an interesting issue for debate. Nevertheless, what is essential is for this association to be acknowledged to allow therapy to be undertaken using the correct approach.

Attention↗

PubMed1998

Reduced transduction mechanisms in the anterior accumbal interface of an animal model of Attention-Deficit Hyperactivity Disorder.

The aim of this study was to map the neural substrates of attention-deficit hyperactivity disorder (ADHD) in the spontaneously hypertensive rat (SHR), which is thought to be a model for ADHD. To this aim, the Ca2+/calmodulin-dependent protein kinase II (CaMKII) and transcription factors (TF) were used as markers. The focus of interest was the nucleus accumbens complex (ACB) which is thought to be an interface between limbic and motor systems. Juvenile, male rats of the SHR line and Wistar-Kyoto (WKY) controls were perfused and the brains processed for immunocytochemistry for CaMKII and the TF peptides of the FOS, JUN-B and ZIF-268 families. The results revealed that: (i) in both groups there were more CaMKII-positive neurones in the shell than in the core of the ACB; (ii) SHR had a reduced number of CaMKII-positive elements in anterior portions of the shell; and (iii) SHR had a lower expression of peptide products of the FOS family (c-FOS, in particular) and ZIF-268. In addition, there was a lower expression of c-FOS and zif-268 in the core of the ACB in the SHR. In contrast, there was an increased basal level of JUN-B in the core of the ACB of SHR. The reduced number of CaMKII and TF-positive elements in the most rostral portions of the accumbal complex of SHR, associated to the higher number of binding sites for the DA D-1/D-5 subtype, appears as a discrete alteration in the prosomeric development of the anterior basal forebrain and could be the key to the understanding of ADHD.

Animals↗

PubMed2003

Searching for the attention deficit in attention deficit hyperactivity disorder: the case of visuospatial orienting.

We review all 14 extant studies of covert visuospatial attention in attention deficit hyperactivity disorder (ADHD) (total N=248). Metaanalysis showed that intriguing but isolated findings of alerting or posterior disengage deficits were too small to reliably detect with the sample sizes typically employed. Posterior move and engage operations and the vigilance sustained attention process were normal in ADHD. For exogenous cues, effect sizes for group differences were homogeneously small across all repeated-measures conditions, as were calculations of cost, benefit, and validity effects. For endogenous cues, effect sizes were heterogeneous; however, calculations of cost, benefit, and validity effects were small and homogenous. The most parsimonious conclusion may be that ADHD is not characterized by significant visual orienting dysfunction, but questions remain about the extent of anterior lateralized effects in the combined subtype and about attentional functioning in the inattentive subtype.

Adolescent↗

PubMed2000

Patterns of alcohol and drug use in adolescents can be predicted by parental substance use disorders.

OBJECTIVE: To examine the specificity of risk for alcohol or drug abuse or dependence (substance use disorders [SUDs]) in offspring exposed to particular subtypes of parental SUDs. METHODS: The original sample was derived from 2 groups of index children: 140 attention-deficit/hyperactivity disorder (ADHD) probands and 120 non-ADHD comparison probands. These groups had 174 and 129 biological siblings and 279 and 240 parents, respectively. RESULTS: Independent of familial risk, exposure to parental SUDs predicted SUDs in the offspring. Controlling for duration of exposure, we found that adolescence was a critical developmental period for exposure to parental SUDs. Because all our analyses controlled for social class, ADHD status, and parental lifetime history of SUDs, these results show that exposure to parental SUDs predicts offspring SUDs independently of these risk factors. CONCLUSIONS: These results support the critical importance of familial environmental risk factors for the development of SUDs in youth in general and particularly in those at high risk for these disorders. These results highlight adolescence as a critical period for the deleterious effects of exposure to parental SUDs, supporting the need to develop preventive and early intervention strategies targeted at adolescents at high risk for SUDs.

Adolescent↗

PubMed2001

Age and sex effects in the EEG: differences in two subtypes of attention-deficit/hyperactivity disorder.

OBJECTIVES: This study investigated age-related changes and sex differences in the EEGs of two groups of children with attention-deficit/hyperactivity disorder (ADHD) combined type and ADHD predominantly inattentive type, in comparison with a control group of normal children. METHODS: Forty boys and forty girls were included in each group. The EEG was recorded during an eyes-closed resting condition and Fourier transformed to provide estimates for total power, absolute and relative power in the delta, theta, alpha and beta bands, and for theta/alpha and theta/beta ratios. RESULTS: Total power, relative alpha, and the theta/alpha and theta/beta ratios were differentiated between all 3 groups. Sex differences between the ADHD subjects and the control group were greater in males than females and matured faster in males. With increasing age, the EEG of the ADHD inattentive group was found to change at a similar rate to the changes found in the normal group, with the differences in power levels remaining constant. In the ADHD combined group, the power was found to change at a greater rate than in the ADHD inattentive group, with power levels of the two ADHD groups becoming similar with age. CONCLUSIONS: These results are supportive of a two-component model of ADHD, with the hyperactive/impulsive component maturing with age and the inattentive component remaining more stable.

Aging↗

PubMed2006

Examining subtypes of behavior problems among 3-year-old children, Part I: investigating validity of subtypes and biological risk-factors.

This study examined 3-year-old children who were classified as hyperactive (HYP), oppositional-defiant (OD), hyperactive and oppositional defiant (HYP/OD), and non-problem based on mothers' reports of behavior. Using fathers,' teachers,' and observers' ratings of children's behavior, concurrent validity was excellent for the HYP/OD group, moderate for the HYP group, and poor for the OD group. As predicted, both the HYP/OD and HYP groups reported more prenatal/perinatal birth complications and a greater family history of hyperactivity than did non-problem children. Furthermore, the HYP/OD group showed a greater family history of conduct disorder and oppositional defiant disorder (ODD) symptoms than did non-problem children; however, the HYP group also showed a greater family history of ODD than did non-problem children. Results suggest that as early as age 3, these behavior subtypes appear to be linked to biologically-based risk-factors in ways that are consistent with theories of the development of ADHD.

Attention Deficit Disorder with Hyperactivity↗

PubMed2001

EEG-defined subtypes of children with attention-deficit/hyperactivity disorder.

OBJECTIVES: This study investigated the presence of EEG clusters within a sample of children with the combined type of attention-deficit/hyperactivity disorder (ADHD). METHODS: Subjects consisted of 184 boys with ADHD and 40 age-matched controls. EEG was recorded from 21 sites during an eyes-closed resting condition and Fourier transformed to provide estimates for total power, and relative power in the delta, theta, alpha and beta bands, and for the theta/beta ratio. Factor analysis was used to group sites into 3 regions, covering frontal, central and posterior regions. These data were subjected to cluster analysis. RESULTS: Three distinct EEG clusters of children with ADHD were found. These were characterized by (a) increased slow wave activity and deficiencies of fast wave, (b) increased high amplitude theta with deficiencies of beta activity, and (c) an excess beta group. CONCLUSIONS: These results indicate that children with ADHD do not constitute a homogenous group in EEG profile terms. This has important implications for studies of the utility of EEG in the diagnosis of ADHD. Efforts aimed at using EEG as a tool to discriminate ADHD children from normals must recognize the variability within the ADHD population if such a tool is to be valid and reliable in clinical practice.

Attention Deficit Disorder with Hyperactivity↗