Different Spectral Analysis Methods for the Theta/Beta Ratio Calculate Different Ratios But Do Not Distinguish ADHD from Controls.

There has been ongoing research on the ratio of theta to beta power (Theta/Beta Ratio, TBR) as an EEG-based test in the diagnosis of ADHD. Earlier studies reported significant TBR differences between patients with ADHD and controls. However, a recent meta-analysis revealed a marked decline of effect size for the difference in TBR between ADHD and controls for studies published in the past decade. Here, we test if differences in EEG processing explain the heterogeneity of findings. We analyzed EEG data from two multi-center clinical studies. Five different EEG signal processing algorithms were applied to calculate the TBR. Differences between resulting TBRs were subsequently assessed for clinical usability in the iSPOT-A dataset. Although there were significant differences in the resulting TBRs, none distinguished between children with and without ADHD, and no consistent associations with ADHD symptoms arose. Different methods for EEG signal processing result in significantly different TBRs. However, none of the methods significantly distinguished between ADHD and healthy controls in our sample. The secular effect size decline for the TBR is most likely explained by factors other than differences in EEG signal processing, e.g. fewer hours of sleep in participants and differences in inclusion criteria for healthy controls.

EEG Theta/Beta Ratio Calculations Differ Between Various EEG Neurofeedback and Assessment Software Packages: Clinical Interpretation.

The quantitative electroencephalographic (QEEG) theta/beta power ratio (TBR) has been shown to have an association with attention-deficit hyperactivity disorder (ADHD), with a previous tacit assumption of equivalence across hardware and software systems. Therefore, the International Collaborative ADHD Neurofeedback (ICAN) randomized clinical trial used a fixed TBR ≥ 4.5 cutoff as measured by the Thought Technology Monastra-Lubar Assessment Suite as an inclusion criterion, 1.5 SD above norms collected with that system. However, a difference was noted between the TBR calculated by that assessment suite and the TBR computed by EEGer, the neurofeedback software used for treatment, leading us to investigate the discrepancy. The difference may arise from different calculation methods. This article explains and compares various computational methods used to calculate and display EEG values, including TBR, elucidating why the values are not equivalent across equipment and software programs. Two major sources of variance are (1) how "spectral leakage" at the ends of bands is handled and (2) whether voltages of bins within a band are first averaged and then squared to get bandwidth power or are first squared to get power (turning negative voltages into positive power) and then averaged to get the bandwidth power; the latter method results in higher band power. This article compares methods of computing the TBR. Biofeedback practitioners and investigators should be aware of the algorithms their systems use when interpreting TBRs and require normative comparison data collected with the same system.

Quantitative electroencephalography and attention-deficit/hyperactivity disorder: implications for clinical practice.

Although behavioral symptoms of inattention, impulsivity, and hyperactivity serve as a foundation for the accurate diagnosis of attention-deficit/hyperactivity disorder (ADHD), the low interrater reliability and specificity of behavioral rating scales and the absence of comprehensive screening for medical conditions that mimic ADHD have created a barrier to the effective treatment of ADHD. Recently published studies using quantitative electroencephalographic techniques have identified abnormal patterns of cortical activation through power spectral analysis, in event-related cortical potentials, and in slow cortical potentials that may serve as a basis for overcoming these barriers. This paper reviews the initial evidence indicating that power spectral analysis and event-related cortical potentials may be useful in differentiating ADHD from other psychiatric disorders, helping in medication selection, evaluating medication response, and improving the rate of treatment initiation and maintenance. Studies examining electroencephalogram biofeedback (neurotherapy) are reviewed using published efficacy guidelines.

Electroencephalographic biofeedback in the treatment of attention-deficit/hyperactivity disorder.

Historically, pharmacological treatments for attention-deficit/hyperactivity disorder (ADHD) have been considered to be the only type of interventions effective for reducing the core symptoms of this condition. However, during the past three decades, a series of case and controlled group studies examining the effects of EEG biofeedback have reported improved attention and behavioral control, increased cortical activation on quantitative electroencephalographic examination, and gains on tests of intelligence and academic achievement in response to this type of treatment. This review paper critically examines the empirical evidence, applying the efficacy guidelines jointly established by the Association for Applied Psychophysiology and Biofeedback (AAPB) and the International Society for Neuronal Regulation (ISNR). On the basis of these scientific principles, EEG biofeedback was determined to be "probably efficacious" for the treatment of ADHD. Although significant clinical improvement was reported in approximately 75% of the patients in each of the published research studies, additional randomized, controlled group studies are needed in order to provide a better estimate of the percentage of patients with ADHD who will demonstrate such gains in clinical practice.

Overcoming the barriers to effective treatment for attention-deficit/hyperactivity disorder: a neuro-educational approach.

Despite specific diagnostic criteria, published practice guidelines for assessing patients, and the availability of effective pharmacological treatments for children diagnosed with attention-deficit/hyperactivity disorder (AD/HD), a review of prescription practices in the United States indicates that as few as 25-50% of these patients receive even minimal medical treatment for this condition. Because untreated children with AD/HD are at increased risk for psychoactive substance abuse, criminal behavior, and other social problems as adults, the provision of effective care during childhood is essential. In order to clarify the factors impeding treatment during childhood and develop a targeted intervention to overcome these barriers, two studies involving 1514 families were conducted. Each family included one child diagnosed with AD/HD. Factors associated with treatment failure or non-compliance with medical advice included: dissatisfaction with a diagnostic process limited to brief observation, interview, and review of behavior rating scales; fear of stimulant medication; lack of medication response within the first month; development of side-effects during the first month; lack of understanding of the reasons stimulants were being prescribed for a child, and insufficient clinical response. Based on these findings, an intervention program consisting of a comprehensive evaluation process (that included neuropsychological and neurophysiological tests of attention, and medical screening for other health problems associated with inattention and hyperactivity) and parent education about the medical causes of AD/HD, the biochemical action of medications, the relationship between dietary habits and attention, and the educational rights of children with AD/HD was conducted. Following completion of this three session intervention, 95% of patients complied with medical recommendations, initiated pharmacological treatment, and continued medication for a 2-year follow-up period. Three percent of the patients were diagnosed and treated for other medical conditions.

Electroencephalographic biofeedback (neurotherapy) as a treatment for attention deficit hyperactivity disorder: rationale and empirical foundation.

During the past three decades, electroencephalographic (EEG) biofeedback has emerged as a nonpharmacologic treatment for attention-deficit/hyperactivity disorder (ADHD). This intervention was derived from operant conditioning studies that demonstrated capacity for neurophysiologic training in humans and other mammals and targets atypical patterns of cortical activation that have been identified consistently in neuroimaging and quantitative EEG studies of patients diagnosed with ADHD. This article presents the rationale for EEG biofeedback and examines the empirical support for this treatment using efficacy guidelines established by the Association for Applied Psychophysiology and Biofeedback and the International Society for Neuronal Regulation. Based on these guidelines, EEG biofeedback is considered to be "probably efficacious" for the treatment of ADHD and merits consideration as a treatment for patients who are stimulant "nonresponders." Although research findings published to date indicate positive clinical response in approximately 75% of patients treated in controlled group studies, additional randomized, controlled trials are needed to provide a better estimate of the robustness of this treatment.

The effects of stimulant therapy, EEG biofeedback, and parenting style on the primary symptoms of attention-deficit/hyperactivity disorder.

One hundred children, ages 6-19, who were diagnosed with attention-deficit/hyperactivity disorder (ADHD), either inattentive or combined types, participated in a study examining the effects of Ritalin, EEG biofeedback, and parenting style on the primary symptoms of ADHD. All of the patients participated in a 1-year, multimodal, outpatient program that included Ritalin, parent counseling, and academic support at school (either a 504 Plan or an IEP). Fifty-one of the participants also received EEG biofeedback therapy. Posttreatment assessments were conducted both with and without stimulant therapy. Significant improvement was noted on the Test of Variables of Attention (TOVA; L. M. Greenberg, 1996) and the Attention Deficit Disorders Evaluation Scale (ADDES; S. B. McCarney, 1995) when participants were tested while using Ritalin. However, only those who had received EEG biofeedback sustained these gains when tested without Ritalin. The results of a Quantitative Electroencephalographic Scanning Process (QEEG-Scan; V. J. Monastra et al., 1999) revealed significant reduction in cortical slowing only in patients who had received EEG biofeedback. Behavioral measures indicated that parenting style exerted a significant moderating effect on the expression of behavioral symptoms at home but not at school.

Assessing attention deficit hyperactivity disorder via quantitative electroencephalography: an initial validation study.

Spectral analysis of the electrophysiological output at a single, midline prefrontal location (the vertex) was conducted in 482 individuals, ages 6-30 years old, to test the hypothesis that cortical slowing in the prefrontal region can serve as a basis for differentiating patients with attention deficit hyperactivity disorder (ADHD) from nonclinical control groups. Participants were classified into 3 groups (ADHD, inattentive; ADHD, combined; and control) on the basis of the results of a standardized clinical interview, behavioral rating scales, and a continuous performance test. Quantitative electroencephalographic (QEEG) findings indicated significant maturational effects in cortical arousal in the prefrontal cortex as well as evidence of cortical slowing in both ADHD groups, regardless of age or sex. Sensitivity of the QEEG-derived attentional index was 86%; specificity was 98%. These findings constituted a positive initial test of a QEEG-based neurometric test for use in the assessment of ADHD.