Repetitive Thoughts and Repetitive Behaviors in Williams Syndrome.

The purpose of the study was to characterize repetitive phenomena in Williams syndrome (WS). The parents of 60 subjects with WS completed the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) or Children's Y-BOCS, the Yale Global Tic Severity Scale, the Stereotyped Behavior Scale, and the Spence Children's Anxiety Scale-Parent Version. Nineteen males and 41 females participated in the study. Six subjects (10%) had obsessions only, six (10%) had compulsions only, and eleven (18%) had at least one obsession and at least one compulsion. None of the subjects had tics. Fifty subjects (83.3%) endorsed at least one stereotypy. Increased anxiety was associated with increased severity of obsessions, but not severity of compulsions or stereotypies.