Theta/Beta Ratio or not?: A Review Study of Specified QEEG Parameter for Diagnosis of ADHD Presentations

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by difficulties in sustaining attention, impulsivity, and hyperactivity According to the DSM-5, three presentations of ADHD are described: combined, predominantly inattentive, and predominantly hyperactive/impulsive. The theta-beta ratio (TBR), also referred to as the inattention index, is defined by increased theta band power (typically 4–7 Hz) and, specifically, increased theta relative to beta band power (typically 13–30 Hz). It has been reported as the most reproducible psychophysiological finding in ADHD. The present study aims to review the literature on QEEG parameters related to ADHD. The design of the study was a systematic review article. Due to increased theta, TBR is reported by many investigators as a consistent characteristic of ADHD. However, it is not a diagnostic measure for all individuals with ADHD. TBR is unnecessary in making the diagnosis for all ADHD presentations. In other words, a review of studies suggests that TBR cannot serve as a comprehensive diagnostic measure for all ADHD subtypes. It should not be generalized to all presentations. Rather, each presentation may have its specific QEEG measure.  Therefore, a QEEG spectrum classification of ADHD population is a significant consideration.