The objective of the proposed study is to assess the efficacy of the herbal St. John’s Wort (SJW) in the treatment of symptoms of obsessive-compulsive disorder (OCD). The approach is to conduct a 12-week, randomized, double blind, placebo controlled, parallel group pilot trial with 30 subjects in each of two arms. The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) will be the primary measure for evaluating OCD. An intention-to-treat analysis will be done to compare the two arms.