Obsessive Compulsive Disorder (OCD) is a serious mental illness that affects millions of people throughout the world. Existing therapies for OCD show limited efficacy, can possess troubling side effects, and often require long-term treatment. Discovery of a new treatment for OCD would have considerable scientific and commercial value. One approach to pharmacotherapy for OCD is the development of selective 5-HT2C receptor agonists, which was the focus of our Phase One work. In Phase Two, we propose to optimize and further develop these leads through a Structure-Activity Relationship (SAR) program of synthesis and biological evaluation. From this project we specifically aim to discover one or more indole analogs showing efficacy in our animal model for OCD that is comparable to approved medications. Such leads will also display favorable drug-like properties. The long term goal of this project is to discover a new, improved pharmaceutical agent for treatment of OCD that can be licensed and developed for ultimate market approval.