FRONTOCORTICAL ACTIVITY IN CHILDREN WITH COMORBIDITY OF TIC DISORDER AND ATTENTION-DEFICIT HYPERACTIVITY DISORDER

Comorbidity of tic disorder (TD) and attention-deficit hyperactivity d isorder (ADHD) in children is common but not fully understood Thus we investigated the effect of TD and ADHD on the amplitude of the postimp erative negative variation (PINV) in children with combined tic + hype ractivity symptoms (TD + HA), PINV was chosen as an indicator of front al lobe functioning that is closely related to self-regulation of beha vior, PINVs of four groups of children (healthy controls, pure TD, pur e ADHD, and combined TD + HA; total number 43) were elicited in an aud itory warned reaction task in three conditions (control = CC, loss-of- control = LoCC, and lack-of-control = LaCC) at midfrontal (Fz) and mid central (Cz) leads of the scalp, Effects of TD and ADHD were revealed only in the noncontrol conditions, being independent in the LaCC, but interactive in the LoCC, Thus, the additive model of psychopathologica l classification concerning the comorbidity of TD and ADHD was only pa rtially supported by the observed pattern of psychophysiological resul ts. (C) 1997 Society of Biological Psychiatry.