QUANTITATIVE EEG DIFFERENCES IN A NONCLINICAL SAMPLE OF CHILDREN WITHADHD AND UNDIFFERENTIATED ADD

Objective: To use quantitative electroencephalographic (EEG) technique s to identify electrophysiological differences between children with d istinct disorders of attention and/or hyperactivity. Method: Forty chi ldren from a prescreened community sample were evaluated by means of b oth spectral EEG and evoked response potential (ERP) techniques. The c hildren were 7 to 13 years of age and were selected on the basis of me mbership in one of the following DSM-III-R categories: attention-defic it hyperactivity disorder (ADHD) (n = 16), undifferentiated attention deficit disorder (UADD) (n = 12), or no disruptive disorder diagnosis (n = 12). Results: Spectral EEG revealed that UADD subjects had less d elta band relative percent power (RPP) (p < .01), more beta band RPP ( p < .01), and ERP findings of a decreased rare tone P300 amplitude (p < .02) compared with the control group. ADHD subjects had spectral EEG findings of increased beta band RPP (p < .05) and ERP findings of an increased common tone N100 latency (p < .02) and a decreased rare tone P300 amplitude (p < .02). Interhemispheric asymmetries appeared to di stinguish the groups: the UADD group had spectral EEG asymmetries; the ADHD group had only ERP asymmetries; and the control group had no asy mmetries. Conclusion: Quantitative EEG techniques may prove useful in differentiating specific subtypes of ADHD.