Obsessive-compulsive symptom clusters and urinary amine correlates in Tourette syndrome.

This study was conducted to identify clusters of obsessive-compulsive characteristics in Tourette syndrome subjects and to explore their neurochemical correlates. Patients completed a 40-item questionnaire assessing obsessive-compulsive symptoms. Each subject had a 24-hour urine specimen collected and analyzed for a variety of biogenic amines and their metabolites. Factor analysis identified eight symptom clusters, the majority of which appeared to reflect obsessive symptoms. Consistent relationships were observed between symptom clusters and levels of catecholamine and indolamine amines and metabolites. Overall, the primary metabolite of serotonin, 5-hydroxyindoleacetic acid, appeared to be the most highly correlated with the individual obsessive-compulsive symptoms.