Clinical Psychopharmacology and Neuroscience Papers in Press available online.

Comparison of Quantitative Electroencephalography between Tic Disorder and Attention-Deficit/Hyperactivity Disorder in Children
Ilju Lee 1, Jiryun Lee 2, Myung Ho Lim 1, Kyoung Min Kim
1Department of Psychology, College of Health Science, Dankook University, 2Department of Psychiatry, Dankook University Hospital, 3Department of Psychiatry, College of Medicine, Dankook University
Objectives: Attention-deficit/hyperactivity disorder (ADHD) and tic disorder (TD) are among the most common comorbid psychopathologies and have a shared genetic basis. The psychopathological and neurophysiological aspects of the mechanism underlying the comorbidity of both disorders have been investigated, but the pathophysiological aspects remain unclear. Therefore, this study aimed to compare the neurophysiological characteristics of ADHD with those of TD using resting-state electroencephalography and exact low-resolution brain electromagnetic tomography (eLORETA) analysis.
Methods: We performed eLORETA analysis based on the resting-state scalp-recorded electrical potential distribution in 34 children with ADHD and 21 age-matched children with TD. Between-group differences in EEG current source density in delta, theta, alpha, beta, and gamma bands were investigated in each cortical region.
Results: Compared with the TD group, the ADHD group showed significantly increased theta activity in the frontal region (superior frontal gyrus, t = 3.37, p < .05; medial frontal gyrus, t = 3.35, p < .05). In contrast, children with TD showed decreased posterior alpha activity than those with ADHD (precuneus, t = -3.40, p < .05; posterior cingulate gyrus, t = -3.38, p < .05). These findings were only significant when the eyes were closed.
Conclusion: Increased theta activity in the frontal region is a neurophysiological marker that can distinguish ADHD from TD. Also, reduced posterior alpha activity might represent aberrant inhibitory control. Further research needs to confirm these characteristics by simultaneously measuring EEG-fMRI.
Accepted Manuscript [Submitted on 2021-05-15, Accepted on 2021-07-23]