Age and gender effects in EEG coherence: II. Boys with attention deficit/hyperactivity disorder.

OBJECTIVE: This study investigated intra-hemispheric and inter-hemispheric EEG coherences as a function of age in boys with different subtypes of Attention Deficit/Hyperactivity Disorder (AD/HD), in comparison with a control group of normal boys. METHODS: Three groups of 40 children (AD/HD combined type, AD/HD inattentive type, and normal controls) participated. Each group contained 8 males in each 1 year band from 8 to 12 years. EEG was recorded from 21 sites during an eyes-closed resting condition. Wave-shape coherence was calculated for 8 intra-hemispheric electrode pairs (4 in each hemisphere), and 8 inter-hemispheric electrode pairs, within each of the delta, theta, alpha and beta bands. RESULTS: Developmental effects in intra-hemispheric coherences at shorter and longer inter-electrode distances generally supported Thatcher's two-compartment model. Control boys showed evidence of development in longer-range inter-hemispheric coherences which was not apparent in AD/HD boys. Boys with AD/HD of the combined type showed qualitatively different anomalies than boys with AD/HD of the inattentive type. CONCLUSIONS: EEG coherences in normal boys of this age range develop systematically with age in a non-linear fashion. Boys with AD/HD do not show this development. They display coherence anomalies which differ in nature between DSM-IV subtypes, suggesting differences which are not relatable to simple symptom severity. SIGNIFICANCE: The data reported here indicate differences in the development of EEG coherences in boys with AD/HD, and point to differences between the AD/HD subtypes which may help understanding of the disorder.     

EEG coherence in children with attention-deficit/hyperactivity disorder and comorbid oppositional defiant disorder.

OBJECTIVES: This study is the first to investigate EEG coherence differences between two groups of children with attention-deficit/hyperactivity disorder combined type (AD/HD), with or without comorbid oppositional defiant disorder (ODD), and normal control subjects. METHODS: Each group consisted of 20 males. All subjects were between the ages of 8 and 12 years, and groups were matched on age. EEG was recorded during an eyes-closed resting condition from 21 monopolar derivations. Wave-shape coherence was calculated for 8 intrahemispheric electrode pairs (4 in each hemisphere), and 8 interhemispheric electrode pairs, within each of the delta, theta, alpha, and beta bands. RESULTS: Children with comorbid AD/HD and ODD had intrahemispheric coherences at shorter inter-electrode distances significantly reduced from those apparent in children with AD/HD without comorbid ODD. Such reduced coherences in the comorbid group appeared to wash out coherence elevations previously noted in AD/HD studies. CONCLUSIONS: The present results suggest that, rather than suffering an additional deficit, children with AD/HD and comorbid ODD show significantly less CNS impairment than AD/HD patients without comorbid ODD. SIGNIFICANCE: These results have treatment implications, suggesting that behavioural training, perhaps using family-based cognitive behavioural therapy, could be useful for those children with AD/HD and comorbid ODD. This should focus on the ODD symptoms, in association with a medication regime focussed on the AD/HD symptoms.     

EEG coherence in attention-deficit/hyperactivity disorder: a comparative study of two DSM-IV types.

OBJECTIVES: This study investigated differences in intrahemispheric and interhemispheric electroencephalographic (EEG) coherences between attention-deficit/hyperactivity disorder (ADHD) and control children, and between children with the Combined (ADHDcom) and Inattentive (ADHDin) types of ADHD. METHODS: Three age- and sex-matched groups of 40 children, aged 8-12 years, diagnosed with ADHDcom, ADHDin, and normal control children, participated in this study. EEG was recorded from 21 sites during an eyes-closed resting condition and Fourier transformed. Wave-shape coherence was calculated for 8 intrahemispheric electrode pairs (4 in each hemisphere), and 8 interhemispheric electrode pairs, within each of the delta, theta, alpha and beta bands. RESULTS: At shorter inter-electrode distances, ADHD children had elevated intrahemispheric coherences in the theta band and reduced lateral differences in the theta and alpha bands. At longer inter-electrode distances, ADHD children had lower intrahemispheric alpha coherences than controls. Frontally, ADHD children had interhemispheric coherences elevated in the delta and theta bands, and reduced in the alpha band. An alpha coherence reduction in temporal regions, and a theta coherence enhancement in central/parietal/occipital regions, were also apparent. ADHDcom had greater intrahemispheric theta and beta coherences than ADHDin. Frontally, ADHDcom had higher levels of interhemispheric coherences than ADHDin for the delta and theta bands. In central/parietal/occipital regions, beta coherences were elevated in ADHDcom. CONCLUSIONS: EEG coherences suggest reduced cortical differentiation and specialisation in ADHD, particularly in cortico-cortical circuits involving theta activity. Generally, ADHDcom children displayed greater anomalies than ADHDin children.     

EEG power and coherence in autistic spectrum disorder.

OBJECTIVE: Autistic spectrum disorder (ASD) has been defined as a neurodevelopmental disorder with associated deficits in executive function, language, emotional, and social function. ASD has been associated with pathophysiology in cerebral organization. The current study investigated quantitative EEG findings in twenty children diagnosed with autistic disorders as compared to 20 controls matched for gender, age and IQ. METHODS: The EEG was recorded during an eyes-closed resting condition and topographical differences in cerebral functioning were examined using estimates of absolute, relative, and total power, as well as intrahemispheric and interhemispheric coherences. RESULTS: There were group differences in power, intrahemispheric and interhemispheric coherences. Findings included excessive theta, primarily in right posterior regions, in autistics. There was also a pattern of deficient delta over the frontal cortex and excessive midline beta. More significantly, there was a pattern of underconnectivity in autistics compared to controls. This included decreased intrahemispheric delta and theta coherences across short to medium and long inter-electrode distances. Interhemispherically, delta and theta coherences were low across the frontal region. Delta, theta and alpha hypocoherence was also evident over the temporal regions. Lastly, there were low delta, theta and beta coherence measurements across posterior regions. CONCLUSIONS: These results suggest dysfunctional integration of frontal and posterior brain regions in autistics along with a pattern of neural underconnectivity. This is consistent with other EEG, MRI and fMRI research suggesting that neural connectivity anomalies are a major deficit leading to autistic symptomatology. SIGNIFICANCE: This paper reports the largest integrated study of EEG power and coherence during a resting state in children suffering autism spectrum disorder.     

Neuropsychological executive functions and DSM-IV ADHD subtypes.

OBJECTIVE: To evaluate and compare a focused set of component neuropsychological executive functions in the DSM-IV attention-deficit/hyperactivity disorder combined (ADHD-C) and inattentive (ADHD-I) subtypes. METHOD: The Stop task, Tower of London, Stroop task, Trailmaking Test, and output speed measures were completed by 105 boys and girls aged 7-12 classified as either DSM-IV ADHD-C (n = 46), ADHD-I (n = 18), or community control (n = 41). RESULTS: Both subtypes had deficits on output speed. A group x gender interaction was observed on the Stop task: boys with ADHD-C were impaired versus boys with ADHD-I, whereas girls in the two subtypes did not differ. The ADHD-C type had a deficit in planning. Neither ADHD group had a deficit in interference control per se, although they were slower than controls on the Stroop tasks. CONCLUSIONS: ADHD-I shares neuropsychological deficits with ADHD-C in the domain of output speed; on most domains the subtypes did not differ. Neuropsychological distinctions between these ADHD subtypes may be few, depending on which domain of executive functioning is assessed, and these distinctions differ by gender. In the case of boys, the two subtypes may be distinguished by the specificity of motor inhibition deficits to ADHD-C.     

Coherence in children with Attention-Deficit/Hyperactivity Disorder and excess beta activity in their EEG.

OBJECTIVE: This study investigated differences in coherence measures between two groups of children with Attention-Deficit/Hyperactivity Disorder (ADHD) - with the typical EEG profile (increased theta and decreased beta activity), and with excess beta activity - and a normal control group. METHODS: Thirty-four children with ADHD were included in each of the typical and excess beta groups, and were age and sex matched with 34 control subjects. EEG was recorded from 21 sites during an eyes-closed resting condition. Wave-shape coherence was calculated for eight intrahemispheric and eight interhemispheric electrode pairs, for the delta, theta, alpha and beta bands. RESULTS: In comparison to the controls, the typical ADHD group primarily had increased intrahemispheric theta and beta coherence at short-medium inter-electrode distances, and increased interhemispheric coherence for theta in the frontal and central/parietal/occipital regions. Their laterality effect for interhemispheric short-medium inter-electrode distances was reduced in the theta band. Differences between the excess beta group and the control group were primarily found in laterality of the intrahemispheric theta coherence at short-medium electrode distances, and increased interhemispheric theta coherence in the frontal regions. Reduced delta coherence in the temporal regions was also found. CONCLUSIONS: These results suggest that ADHD children with excess beta power have an underlying brain dysfunction in the frontal lobes which is found in common with children with the typical EEG profile. However a number of qualitative differences exist which could be associated with other aspects of the ADHD diagnosis or another comorbid condition. SIGNIFICANCE: This is the first study to investigate EEG coherence in ADHD children who have increased beta power.     

Age and gender effects in EEG coherence: I. Developmental trends in normal children.

OBJECTIVE: This study investigated intra-hemispheric and inter-hemispheric EEG coherences as a function of age and gender in normal children. METHODS: Two groups of 40 boys and 40 girls, each containing 8 normal children in each 1-year band from 8 to 12 years, participated. EEG was recorded from 21 sites during an eyes-closed resting condition. Wave-shape coherence was calculated for 8 intra-hemispheric electrode pairs (4 in each hemisphere), and 8 inter-hemispheric electrode pairs, within each of the delta, theta, alpha and beta bands. RESULTS: There was consistent evidence of coherences developing across this age range, particularly in long-range intra- and inter-hemispheric electrode pairs. Coherences were larger in the left hemisphere than the right. Coherences also appeared to develop further in males than females, across several regions and frequency bands, suggesting that females lag males in this aspect of brain development. CONCLUSIONS: EEG coherences in normal children of this age range develop systematically with age. These developmental effects vary substantially with gender, brain region and frequency bands. SIGNIFICANCE: The data reported here provide basic norms for coherence development in different brain regions in normal children.     

Event-related slow-wave activity in two subtypes of attention-deficit/hyperactivity disorder.

OBJECTIVE: Previous time-frequency studies have indicated that event-related low-frequency activity has important effects on component topography and developmental effects in auditory event-related potentials (ERPs) of children and adolescents. This study investigated the influence of event-related slow-wave (SW) (0.01-2 Hz) activity in the group differences seen between children with and without attention-deficit/hyperactivity disorder (AD/HD) of different subtypes. METHODS: Time-frequency analysis techniques were applied to auditory ERP data derived from children with AD/HD predominantly inattentive type (n = 30), AD/HD combined type (n = 30) and age-matched control subjects (n = 30). RESULTS: Event-related early frontal negative and late posterior positive SW components were reduced in the AD/HD combined type group, but not AD/HD inattentive type group, relative to controls. The RESIDUAL ERPs, which represented event-related 2-12 Hz activity, showed clinical vs. control group differences in components that were similar in both AD/HD subtype groups. CONCLUSIONS: The time-frequency results showed that event-related SW (0.1-2 Hz) activity contributes importantly to group differences between AD/HD and control children, and the pattern of group differences from controls for each of the AD/HD subtype groups, which are evident in raw ERPs. These results emphasise both the clinical and developmental importance of this form of analysis. SIGNIFICANCE: This novel approach revealed additional specific information about stimulus processing and regional inhibition/activation in two AD/HD subtypes, relative to control subjects.     

Cerebrovascular disease and hippocampal atrophy are differently linked to functional coupling of brain areas: an EEG coherence study in MCI subjects

The working hypothesis of paper is that the functional coupling of brain areas is combined with different neuroradiological substrates and has different clinical manifestations. 31 normal old subjects and 85 subjects with mild cognitive impairment (MCI) underwent EEG recordings and magnetic resonance imaging (MRI). Intrahemispheric and interhemispheric linear EEG coherences were computed. At first, all normal old and MCI subjects were compared. Subsequently, three subgroups of MCI were obtained based on neuroradiological substrate (subcortical cerebrovascular damage, MCI-CVD; cholinergic pathways vascular damage MCI-CHOL; and hippocampal atrophy, MCI-HIPP) and compared with a normal old sample matched for age, education and Mini-Mental State Examination score. The group of MCI subjects compared to normal old subjects shows: 1) decrease of intrahemispheric coherence in fronto-parietal regions (both right and left hemisphere); 2) increase of interhemispheric coherence on frontal regions in delta frequency; and 3) increase of interhemispheric coherence on temporal regions (from delta to alpha3 frequency bands). In the MCI subgroups, hippocampal atrophy is linked to an increase of interhemispheric coherence seen on frontal and temporal regions whereas subcortical CVD is linked to the largest decrease of coherence in fronto-parietal regions. MCI-CVD patients performed worst on Trail Making Test battery whereas MCI-HIPP patients were impaired on Rey word list delayed recall and Rey figure recall.     

Does actigraphy differentiate ADHD subtypes in a clinical research setting?

OBJECTIVE: To compare subtypes of attention-deficit/hyperactivity disorder (ADHD) (predominantly inattentive and combined types) and a comparison group on an objective measure of activity level (actigraphy). METHOD: Actigraphs were worn by 64 children (49 boys, 15 girls) during a full-day clinical diagnostic assessment; 20 subjects had a diagnosis of ADHD predominantly inattentive type, 22 had ADHD combined type, and 22 were non-ADHD controls. Mean actigraph scores were calculated for two 2-hour intervals, comprising, respectively, a psychometric evaluation in the morning and the completion of a speech and language assessment and research measures in the afternoon. RESULTS: There were no significant group differences in activity level in the morning session. During the afternoon session, children with ADHD were significantly more active than controls, but there were no differences between ADHD subtypes. CONCLUSIONS: These data partially support specifications in the DSM-IV regarding hyperactivity in ADHD; however, they also indicate that situational and/or temporal factors may affect the degree to which hyperactivity is expressed. Furthermore, the findings contradict specifications in the DSM-IV that suggest that children with ADHD combined type should be more hyperactive than children with ADHD predominantly inattentive type.     

Ultradian rhythms and temporal coherence in sleep EEG in depressed children and adolescents.

BACKGROUND: It has been suggested that a primary ultradian (80-120 minute) rhythm disturbance in EEG underlies sleep abnormalities in adults with depression. The present study evaluated ultradian rhythm disturbances in childhood and adolescent depression. METHODS: Sleep macroarchitecture and temporal coherence in quantitative EEG rhythms were investigated in 50 medication-free outpatients with major depression (25 children and 25 adolescents) and 15 healthy normal controls (5 children and 10 adolescents). RESULTS: Few of the macroarchitectural measures showed significant group effects. In fact, age and sex effects were stronger than disease-dependent components. Temporal coherence of EEG rhythms during sleep did differentiate those with MDD from controls. Both depressed children and adolescents had lower intrahemispheric coherence, whereas interhemispheric was only lower in depressed adolescents in comparison with controls. Gender differences were evident in adolescents, but not children, with MDD with lowest interhemispheric coherence in adolescent girls. CONCLUSIONS: These findings are in keeping with increased risk for depression in females beginning at adolescence and extending throughout adulthood. It was suggested that low temporal coherence in depression reflects a disruption in the fundamental basic rest-activity cycle of arousal and organization in the brain that is strongly influenced by gender.     

Abnormal functional connectivity in Alzheimer’s disease: intrahemispheric EEG coherence during rest and photic stimulation

Electroencephalography (EEG) coherence provides a measure of functional correlations between two EEG signals. The present study was conducted to examine intrahemispheric EEG coherence at rest and during photic stimulation (PS; 5, 10 and 15 Hz) in ten unmedicated patients with presenile dementia of the Alzheimer type (AD; mean age at onset 56 years). In the resting EEG, the AD patients had significantly lower coherence than gender- and age-matched control subjects in the alpha-1, alpha-2 and beta-1 frequency bands. The EEG analysis during PS also showed that the patients had significantly lower coherence in the frequency corresponding to PS at 10 and 15 Hz. In this study, the changes in coherence from the resting state to the stimulus condition (i.e. PS-related coherence reactivity) were examined. The patients were found to show significantly smaller coherence reactivity to PS at 5 and 15 Hz. These findings suggest that, in addition to the resting state, AD patients have an impairment of intrahemispheric functional connectivity during PS. They also suggest that AD shows a failure of PS-related functional reorganization. Received: 5 August 1997 / Accepted: 18 June 1998     

Should sluggish cognitive tempo symptoms be included in the diagnosis of attention-deficit/hyperactivity disorder?

OBJECTIVE: To determine the impact of including sluggish cognitive tempo items on the factor and latent class structure of attention-deficit/hyperactivity disorder (ADHD) subtypes in boys and girls. METHOD: Parent report of two sluggish cognitive tempo items on a population-based sample of 1430 female twins and 1414 male twins were analyzed along with parent report of the 18 DSM-IV ADHD items using principal components analysis and latent class analysis. RESULTS: The inclusion of the two sluggish cognitive tempo items resulted in distinct factor structures for boys and girls. For boys there were separate inattentive, hyperactive/impulsive, and sluggish factors. For girls there were separate inattentive/sluggish, hyperactive, and impulsive factors. In contrast, sluggish cognitive tempo items had minimal impact on the latent class structure of ADHD for both boys and girls. CONCLUSIONS: The inclusion of sluggish cognitive tempo items markedly changed ADHD symptom associations for boys and girls in a factor analytic framework. In contrast, latent class subtyping of ADHD shows limited impact of the inclusion of sluggish cognitive tempo items, emphasizing the very different assumptions about underlying continua of behavior rather than discrete classes that distinguish the two approaches.     

EEG and electrodermal activity in girls with Attention-Deficit/Hyperactivity Disorder

ObjectiveThis study investigated the Hypoarousal Model of Attention-Deficit/Hyperactivity Disorder (AD/HD) in girls.Methods40 girls with AD/HD and 40 girl controls (aged 7–12 years) had an eyes-closed resting EEG recorded from 19 electrodes and Fourier transformed. Estimates for total power, absolute and relative power in the delta, theta, alpha, beta and gamma frequency bands, and theta/beta ratio were analysed in nine cortical regions. Skin conductance level (SCL) was simultaneously recorded. Regression analyses explored relationships between symptoms and physiology.ResultsCompared with controls, girls with AD/HD had globally elevated relative delta, globally reduced absolute beta, and globally reduced absolute and relative gamma activity. Girls with AD/HD also had lower mean SCL. Inattentive symptoms were predicted by elevated frontal relative delta, reduced SCL, and reduced temporal relative gamma activity, while elevated hyperactive–impulsive symptoms correlated with elevated frontal relative delta activity in both the patient and control groups.ConclusionsThese EEG results are comparable with the limited female AD/HD literature. Girls with AD/HD are hypoaroused, indicated by reduced SCL, and appear to have an anomalous arousal mechanism. Absolute and relative gamma results are similar to previous findings in AD/HD children. Symptom correlations with physiology offer intriguing insights for future research.SignificanceThis is the first study to examine CNS arousal exclusively in girls with AD/HD.     

EEG coherence obtained from an auditory oddball task increases with age.

Changes in coherence with aging during cognitive tasks have, until now, not been investigated. However, several fMRI and positron emission tomography studies of cognitive tasks have found increased bilateral activity in elderly subjects. Changes in coherence with aging during a cognitive task were investigated to see if EEG coherence was present in older adults. An auditory oddball task, which is a widely used test for cognitive function, was used. Eleven young adults (27.8 +/- 4.8 years, six females) and 10 older adults (61.3 +/- 4.6 years, six females) were studied, and both interhemispheric and long- and short-range intrahemispheric coherence were considered. Higher interhemispheric coherence was found in the older subjects in the delta band. Short intrahemispheric coherence was also increased in the theta, delta, and alpha bands. Higher coherence, although not significantly different, was also found for all other coherence types and bands, except for long intrahemispheric coherence in the low gamma band. The results presented here provide the first evidence that aging is associated with increased EEG coherence during a relatively easy cognitive task.     

Gender differences among children with DSM-IV ADHD in Australia

OBJECTIVE: To examine gender differences among children meeting symptom criteria for DSM-IV attention-deficit/hyperactivity disorder (ADHD) identified in a nationally representative sample of Australian children. METHOD: From 2,404 children aged 6 to 13 years, 225 boys and 99 girls with ADHD symptoms were identified using the parent version of the Diagnostic Interview Schedule for Children and compared on parent reports of children's behavioral problems and impairment. RESULTS: When ADHD types were collapsed into a single group, boys and girls did not differ on core symptoms, comorbidity, and impairment with the exception that girls rated higher on somatic complaints and boys had poorer school functioning. However, gender patterns were found to vary across ADHD type on impairment measures of social problems, schoolwork difficulties, and self-esteem, with boys being generally rated as more impaired in the combined and hyperactive-impulsive groups but equally or less impaired in the inattentive group. CONCLUSIONS: The findings suggest the possibility of gender-specific risks associated with high levels of inattentive and hyperactive-impulsive symptoms indicating that ADHD subtype membership should be considered when conducting ADHD gender comparisons.     

Correlation Between EEG Activity and Behavior in Children with Attention-Deficit/Hyperactivity Disorder

The aim of this study was to determine whether EEG activity in specific bands correlated with the core behavioral symptoms of children with attention-deficit/hyperactivity disorder (AD/HD). Sixty boys diagnosed with AD/HD Combined type and 60 age-matched male controls participated in this study. An EEG was recorded during an eyes-closed resting condition and relative power estimates in the delta, theta, alpha, and beta bands, and the theta/beta ratio, were calculated. The EEG measures of the AD/HD group were converted to z scores relative to the controls, and these were correlated with scores on the Conners' Rating Scale obtained from a parent. The AD/HD group had global increases in theta activity and the theta/beta ratio, increased frontal delta, with reduced global alpha and frontal beta activity. Frontal theta activity correlated with inattention, the theta/beta ratio correlated with hyperactivity-impulsivity, and both measures correlated with a Combined type diagnosis. EEG power anomalies in AD/HD are associated with specific symptom clusters in the disorder.     

Influence of gender on attention deficit hyperactivity disorder in children referred to a psychiatric clinic.

OBJECTIVE: The substantial discrepancy in the male-to-female ratio between clinic-referred (10 to 1) and community (3 to 1) samples of children with attention deficit hyperactivity disorder (ADHD) suggests that gender differences may be operant in the phenotypic expression of ADHD. In this study the authors systematically examined the impact of gender on the clinical features of ADHD in a group of children referred to a clinic. METHOD: The study included 140 boys and 140 girls with ADHD and 120 boys and 122 girls without ADHD as comparison subjects. All subjects were systematically assessed with structured diagnostic interviews and neuropsychological batteries for subtypes of ADHD as well as emotional, school, intellectual, interpersonal, and family functioning. RESULTS: Girls with ADHD were more likely than boys to have the predominantly inattentive type of ADHD, less likely to have a learning disability, and less likely to manifest problems in school or in their spare time. In addition, girls with ADHD were at less risk for comorbid major depression, conduct disorder, and oppositional defiant disorder than boys with ADHD. A statistically significant gender-by-ADHD interaction was identified for comorbid substance use disorders as well. CONCLUSIONS: The lower likelihood for girls to manifest psychiatric, cognitive, and functional impairment than boys could result in gender-based referral bias unfavorable to girls with ADHD.     

Functional interactions within the newborn brain investigated by adaptive coherence analysis of EEG.

To assess functional cortical organization in newborns during quiet sleep we investigated instantaneous interhemispheric coherences in six healthy full-term subjects using linked ear reference and average reference. Tracé alternant was the most frequent EEG pattern during quiet sleep of these newborns and consists of burst and interburst periods. The calculation of coherence was performed by means of time-variant autoregressive models on the basis of Kalman filtering. Coherence changes simultaneously with the appearance of these burst and interburst periods. The highest level of coherence was observed during burst periods in comparison with interburst periods. The lowest level of coherence was observed just before the burst started. During burst, maximal coherence was reached at different moments--late in the low frequency band (0.5-1.5 Hz; about 3 s after the burst started) and earlier in higher frequency bands (> 2 Hz, about 2 s). Interhemispheric coherence depended on the region being investigated. A significant level of coherence could be observed over frontal, temporal and occipital regions. Our data demonstrate significant modification of interhemispheric coherence during quiet sleep of full-term newborns and, irrespective of the immaturity of the brain, these coherences differ significantly between cortical regions.     

Examining the diagnostic utility of EEG power measures in children with attention deficit/hyperactivity disorder.

OBJECTIVE: This study investigated the diagnostic utility of EEG power during eyes-closed resting conditions for children with attention-deficit/hyperactivity disorder (AD/HD). METHODS: Subjects consisted of 253 boys with AD/HD combined type and 67 age-matched controls. EEG was recorded from 21 sites during an eyes-closed resting condition and was Fourier transformed to provide estimates for total power and absolute and relative power in delta, theta, alpha and beta bands. Factor analysis was used to group sites into frontal, central and posterior regions, with these data subjected to cluster analysis. Logistic regression was performed on the entire AD/HD sample versus control, for AD/HD clusters versus control, and then for each AD/HD cluster independently versus control, using total, absolute and relative power measures. RESULTS: Logistic regression performed on the clusters independently produced the best classification results, with a sensitivity of 89.0% and a specificity of 79.6%, with an overall classification accuracy of 87.0%. CONCLUSIONS: The obtained classification results are supportive of an independent diagnostic test for AD/HD based on EEG power at rest. SIGNIFICANCE: This is the first study to investigate sensitivity and specificity of EEG power for AD/HD in a resting condition.