Grant: CIHR Fellowship

Background: Obsessive-compulsive disorder (OCD) is a common and chronic psychiatric disorder that affects the communication between different parts of the brain, thereby disrupting brain functions. Evidence suggests that genes play an important role in the development of this disorder because it runs in families. Given that there are many possible symptoms in OCD, the identification of one genetic link has been difficult. Prior research shows that genes also contribute to whether a patient will respond to one medication versus the other. The first-line treatment for OCD is the selected serotonin reuptake inhibitors (SSRIs) antidepressant, which attempts to regulate the balance of serotonin (5-HT), a neurochemical in the brain. In determining the genetic basis of the different subtypes of OCD and antidepressant response in OCD, 5-HT and other neurochemical genes are potential candidates. Aim: The purpose of this study is to identify DNA variants that contribute to the risk for developing OCD and its subtype as well as antidepressant response. Method: Genotyping data derived from a Genome Wide Association Study of OCD (sample size approximately 1500) of which Dr. Richter's group was a contributor provides an interesting opportunity to explore the genetic basis of OCD subtypes and antidepressant response. We will test for associations between the DNA variation frequencies of the examined genes and different subtypes of OCD or antidepressant response. Implications: This study is designed to examine the genetic susceptibility and antidepressant response in OCD. Thus, we may better understand genetic factors for risk to developing OCD. The identification of genetic factors that contribute to antidepressant response is vitally important in identifying those who are responder. This will help the clinician to choose the best tolerated medications in order to prevent the significant morbidity and mortality in patients with OCD.