A cross-national EEG study of children with emotional and behavioral problems: a WHO collaborative study in the Western Pacific Region.

Electroencephalograms (EEGs) of children from the general population, assessed by Rutter's questionnaires as having deviant behavior, were quantitatively evaluated in Japan (n = 27), China (n = 39), and Korea (n = 87). Compared with age-matched normal behavior children in Japan (n = 30), China (n = 27), and Korea (n = 26), there were no differences either in the EEG frequency pattern or other EEG variables. The EEGs of age-matched children diagnosed with attention deficit disorder with hyperactivity in psychiatric clinics in Japan (n = 21), China (n = 41), and Korea (n = 29), were significantly different from those of normal and deviant behavior groups. There were more delta and fast theta waves and fewer alpha waves in all three countries, and hypothetical EEG maturation was retarded in Japan and China. These results suggest that the deviant behavior of children in the general population had no biological background, but presumably stemmed from psychosocial disadvantages. In contrast, the symptoms of hyperactive children seemed to be related to a biological dysfunction such as brain immaturity.