Grant: Operating Grant

Obsessive-compulsive disorder (OCD) is a serious, disabling and under-diagnosed psychiatric illness that affects 1-3% of Canadians. Although effective treatments such as cognitive-behaviour therapy (CBT) and medications exist for OCD, their access is often delayed for years due to limitations of trained clinicians, long waitlists and high costs. Sadly, treatment response rates and outcomes worsen as OCD duration increases. Childhood-onset OCD (CO-OCD) is the form of OCD that is most strongly influenced by genetic factors, such that siblings of affected youth have a 10-fold increased risk for developing OCD. Yet risk genes have not been identified despite many costly and large genetic studies. What is clear is that OCD is associated with difficulties performing tasks that assess brain performance, and also with subtle findings on physical exam, called neurological soft signs (NSS). For other complex genetic disorders such as schizophrenia, brain performance abnormalities and NSS have also been found in unaffected relatives, and this discovery has helped gene and outcome research. However, for OCD, predicting who will develop the illness and whether they will respond to CBT remains challenging. Our main objective is to compare brain performance and NSS data across CO-OCD, unaffected siblings and healthy control groups. We will examine both the suitability of this performance and NSS data as genetic risk markers to better understand the disorder, and the potential to use this data in clinical settings to better manage the disorder. Response of the CO-OCD group to CBT will also be measured. This will be the first study of its kind in CO-OCD, an important subtype given its increased genetic influence. Our study is significant given its potential to identify CBT response predictors. These goals align with CIHR's mission to produce new scientific knowledge and to enable knowledge translation to improve health and strengthen our Canadian health care system.