ERP differences among subtypes of pervasive developmental disorders

Background: Children with multiple complex developmental disorder (MCDD) ha ve been distinguished from autistic children on the basis of chart reviews. It was questioned whether it is possible to find other, e.g., event-relate d potential (ERP), evidence for this assertion. Methods: ERPs were measured in response to stimuli in a visual oddball task in autistic, MCDD, attention deficit disorder, dyslexic, and normal contro l children, to study whether ERP peaks can be used to distinguish autistic and MCDD children, and to classify the aforementioned groups. Results: It was found that the P3 at four different leads and the frontal N c showed differences among the groups, and that the autistic and MCDD group s differed from each other as well as from the other groups. Also, it was f ound that, using discriminant analyses in which these parameters were inclu ded, children were classified above chance level. Especially in the MCDD gr oup, a high percentage of correct classification was seen. Conclusions: ERP parameters indicate that autistic and MCDD children might differ in underlying pathology and might therefore, better be regarded as t wo separate diagnostic entities. (C) 1999 Society of Biological Psychiatry.