Differences in Electroencephalography Power and Asymmetry at Frontal Region in Young Adults with Attention-deficit/hyperactivity Disorder: A Quantitative Electroencephalography Study.

Objective: : Diagnosing attention-deficit/hyperactivity disorder (ADHD) in adults is often hard. This study aimed to determine differences in absolute EEG power and frontal asymmetry between individuals with ADHD and non-ADHD in young adults aged 18-30 years. Methods: : Young adult (age: 18-30 years) outpatients (n = 103) including ADHD patients (n = 51) and non-ADHD patients (n = 52) were enrolled. QEEG was performed for both groups for each region of the brain. The absolute power of each frequency measured in three frontal regions (Lt., Mid., Rt.) of the scalp area was compared between the two groups. Differences between the two groups including theta/beta ratio were compared. Frontal asymmetries were also evaluated for prefrontal (Fp2-Fp1), middle frontal (F4-F3), lateral frontal (F8-F7) pairs at all frequencies. Correlation analysis was performed for absolute powers, frontal asymmetry, and Stroop tests. Results: : Demographic data, neuropsychological tests, and psychiatric symptoms were not significantly different between the two groups. Delta band was significantly increased while beta band was decreased in the middle frontal area of the ADHD group as compared with those of the non-ADHD group. For frontal asymmetries, all frequencies in the middle frontal area were more rightward in ADHD patients than in non-ADHD patients. Absolute powers in delta, beta band, and frontal asymmetry in all frequencies had correlations with Stroop tests. Conclusion: : This study revealed that ADHD patients had significant differences in absolute powers in delta, beta bands, and frontal asymmetries in all frequencies. Our findings suggest that QEEG can be a helpful tool for diagnosing ADHD in psychiatric patients.