Background: The purpose of this study was to examine the probability of obsessive and compulsive (OC) symptoms across stages of Huntington's disease (HD) with both cross sectional and longitudinal data.
Methods: We present the largest sample to date of individuals at risk for HD (N = 3964). Obsessive and compulsive symptoms were assessed with the Unified Huntington's Disease Rating Scale OC items.
Results: The probability of meeting the threshold for obsessions and compulsions increased with greater disease severity. Those with no motor abnormalities ("at risk") had a 7% probability of obsessions and a 3.5% probability of compulsions; the peak probability for obsessions (24%) and compulsions (12%) occurred in patients with advanced disease with significant functional disability.
Conclusions: The probability of OC symptoms is more than three times greater by stages 3 and 4 (clearly manifest disease) than in our at-risk group with no apparent motor abnormalities.