Sensing brainwave dynamics in masked attention-deficit/hyper activity disorder: A quantitative electroencephalography-based approach to quantifying electrophysiological biomarkers in a high-functioning adult.

The diagnosis of attention-deficit/hyperactivity disorder (ADHD) in high-functioning adults is challenging, often relying on subjective reports which can be confounded by compensatory mechanisms. Quantitative electroencephalography (QEEG) is an objective neurophysiological tool that can identify biomarkers associated with attentional dysregulation. This case report aims to illustrate the clinical utility of QEEG in characterizing the neural correlates of suspected ADHD in a high-functioning adult female. A 31-year-old high-functioning female with chronic symptoms of inattention and executive dysfunction underwent an eight-channel resting-state QEEG assessment under both eyes-open (EO) and eyes-closed (EC) conditions. Data were analyzed using the Fast Fourier Transform (FFT) to determine the absolute and relative power of spectral bands and to compute key frequency ratios, including the theta/beta ratio (TBR). To confirm the clinical diagnosis of ADHD and exclude comorbid psychiatric or neurodevelopmental disorders, standardized diagnostic tools were employed, including the DIVA 2.0 structured interview. Data analysis revealed a marked excess of relative theta power in frontal and central regions, which persisted and amplified in the EC condition (<i>e.g.</i>, F3: 21.37% in EO vs. 27.10% in EC). The TBR in frontal leads surpassed the clinical threshold of 1.5. Notably, a paradoxical alpha response was observed, with a decrease in posterior Alpha power upon eye closure. A mild rightward frontal asymmetry was also present. We found that the patient's QEEG profile provided objective, quantifiable evidence that supports her subjective clinical presentation and is consistent with neurophysiological subtypes of adult ADHD. This case highlights the value of QEEG as an adjunctive diagnostic tool for illustrating potential neural correlates of ADHD in high-functioning individuals and for suggesting potential targets for therapeutic strategies. While this single-case study highlights QEEG's potential, the findings underscore the need for larger-scale research to validate these neuromarkers for broader clinical application.