Comparison of Quantitative Electroencephalography (qEEG) Indices in Children with Attention Deficit- Hyperactivity Disorder and Healthy Children

Research Article

Austin Child Adolesc Psychiatry. 2016; 1(1): 1003.

Comparison of Quantitative Electroencephalography (qEEG) Indices in Children with Attention Deficit- Hyperactivity Disorder and Healthy Childrens

Malek A¹, Shahrokhi H¹, Amiri S¹*, Ayromlou H², Safaiyan A3 and Nasiri M¹

¹Research Center of Psychiatry and Behavioral Sciences, Tabriz University of Medical Sciences, Iran

²Department of Neurology, Tabriz University of Medical Sciences, Iran

³Department of Biostatistics and Epidemiology, Tabriz University of Medical Sciences, Iran

*Corresponding author: Shahrokh Amiri, Department of Psychiatry, Associate professor of Child and Adolescent Psychiatry, Research Center of Psychiatry and Behavioral Sciences, Tabriz University of Medical Sciences, Razi Psychiatric University Hospital, El-goli Boulevard, Tabriz 51677, East Azerbaijan, Iran

Received: July 22, 2016; Accepted: September 20, 2016; Published: September 22, 2016


Background: Electroencephalographic (EEG) indices provide objective and useful measures of ongoing brain activity. They may have a role in ADHD diagnosis. This study aims at evaluating the findings of quantitative EEG (QEEG) in children with ADHD.

Methods: In this cross-sectional controlled study, 30 male children with ADHD aged 6-12 years were compared with 30 male age-matched healthy children. The QEEG was performed in all participants and the data with regard to the brain waves were compared between the two groups.

Results: Regarding the band type, generalized decrease in absolute power of “high-beta” waves was found in the ADHD group. The power ratio of alpha, beta, delta and theta waves to high-beta wave were increased in the ADHD group in decreasing order. The recorded waves from the frontal, parietal and occipital lobes, with different absolute power between the two groups, were demonstrated to have a significant preponderance in children with ADHD. This preponderance was in favor of the control group in the temporal lobe. There was not a significant difference in central region between the two groups.

Conclusion: According to our results, generalized decrease in absolute power of “high-beta” waves was a constant finding in ADHD children.

Keywords: Attention deficit/hyperactivity disorder; ADHD; Electroencephalography; Quantitative


Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common reasons for referral of youth to out-patient child and adolescent psychiatric clinics, with many adverse outcomes and complications [1]. This accounts for the necessity of accurate and timely diagnosis of the disorder and the subsequent administration of appropriate treatment. In the existing diagnostic systems, pathological behaviors are the basis for the diagnosis of this disorder [2]. Such a diagnostic procedure has major drawbacks; first, relying on behavioral indicators and caregivers’ reports or even medical observations may be subject to cultural requirements, and expectations, tolerance levels or even the personal condition of the evaluator [1]. On the other hand, similar behaviors might have different underlying causes that essentially allow one to question whether the disorder is identical in nature [3]. The stated flaws in the diagnostic system as well as attempts towards finding a more accurate treatment based on the underlying pathology have led researchers to examine brain functions under such a condition. In this regard, one of the critical research lines has been in the field of Electroencephalography (EEG). In the past 30 years, EEG has been repeatedly used to find differences between healthy children and those with ADHD, which has yielded significant results. These results consist mainly of an increase in slow-wave activity and a decreased activity of the high-frequency waves [3,4]. However, the results of these studies were heterogeneous [5-7]. On the other hand, as the symptoms of the psychiatric disorders may have a cultural nature, obtaining similar objective results among Iranian patients to what has been obtained in the aforementioned studies would help up verify the identical nature of what is known and treated as ADHD in Iran with that in the other countries. So, we carried out the present study with the aim of investigating the quantitative EEG (QEEG) indices in Iranian children with ADHD.

Materials and Methods

In this cross-sectional controlled study, 64 children ranging from 6-12 years of age were enrolled in two groups: 32 male children with ADHD were selected through convenience sampling method and 32 male age-matched healthy children (control group) were enrolled randomly from the city. Finally, two patients from each group withdrew from the study and investigations were conducted on 30 remaining patients in each group. The research setting was the Imam Reza Hospital’s EEG Center, Tabriz-Iran. The case group consisted of 30 boys with ADHD and no history of psychiatric drug treatment, based on initial clinical diagnosis of children performed by a child and adolescent psychiatrist. To rule out IQ Problems, children were referred to a clinical psychologist to undergo an IQ test by The Wechsler Intelligence Scale for Children (WISC). In case of absence of intellectual disability, a neurologist would visit the patients. If there were no signs of neurological or physical illnesses, a psychiatry resident would confirm the diagnosis ADHD through semi-structured diagnostic interview using Kiddie Schedule for Affective Disorders and Schizphrenia – Present & Lifetime version (K-SADS-PL) [8] and look for other psychiatric disorders. In the absence of any intervening psychiatric disorders, the child was introduced to undergo QEEG. 30 healthy male children (control group) in the same age range were selected from the city of Tabriz using a multi-stage sampling method. These children were selected and added to the present study from a concurrent ongoing epidemiological study of child and adolescent psychiatric disorders in Tabriz, Iran, based on the results of the initial screening as the healthy children. The health of this group was verified through diagnostic psychiatric interview using Kiddie-SADS and neurological examinations. Quantitative EEGs in this group were conducted with the same conditions as those in the case group. 10 artifact-free traces, prepared through the standard mode, were selected for quantitative analysis. Based on the frequency band, waves were divided into Delta (1-3.5 Hz), theta (4-7.5 Hz), Alpha (8-12 Hz), beta (12.5-25 Hz) and high beta (25.5-30 Hz) groups. The locations of the recorded waves included the frontal, central, parietal, occipital, and temporal lobes. Moreover, the closed/open eye condition was considered at the time of recording. Waves were analyzed with regard to three aspects: Absolute power (AB), Relative power (RE), and Power ratio (PR). This research has been approved by the Ethics Committee of Tabriz University of Medical Sciences. The obtained data were expressed in the form of mean ± standard error (Mean ± SE), as well as frequency and percentage. The statistical software used in this study was SPSS™ version 15. Comparisons were made via Independent Samples T-test. Results with P<0/05 were regarded as statistically significant.


30 male children with ADHD (case group), and 30 healthy male children (control group), were included in the study. The mean age of children in the control group was 10.5±0.2 years, and the mean age of the case group was 10.0±0.2 years. In this regard, there were no statistically significant differences between the two groups (p=0/114).

QEEG analyses for absolute power of waves are summarized in Table 1 with statistically significant differences between the two groups. In this regard, the mean absolute power of beta waves in the temporal lobe, and that of the delta waves in the frontal lobe were higher in the case group compared to the control group. The mean absolute power of high beta waves in the central, frontal, and the temporal regions were higher in the control group than the case group.