Grant: Project Grant

Obsessive compulsive disorder (OCD) is important, affecting 2% of adolescents and adults. A third of people with this illness do not respond well to treatment. A second problem is half of people who get OCD also get clinical depression. This type of clinical depression may be different from clinical depression without OCD and is very resistant to treatment. More information about the brain in OCD and OCD with clinical depression is needed to make new cures. We have a new imaging technique to measure the density of connections between nerves in the brain. We noticed in pilot data that connections are greatly increased (about 20%) in OCD compared to people who are healthy and a similar difference between OCD with clinical depression versus clinical depression without OCD. This study will compare density of connections between nerves across four groups. The density of connections across these groups, from highest to lowest, is expected as follows: OCD, OCD with clinical depression, healthy, clinical depression without OCD. Increased connections may make some pathways get used too much in OCD. This may make it hard for the brain to be flexible and adapt to the environment, leading to repetitions of thoughts and actions seen in OCD, and lack of adapting to changing emotional demands in OCD with clinical depression. This would be the first study to discover greater connections between nerves in the brain of OCD and OCD with clinical depression. Too many connections argues for a new way to treat these illnesses by reducing excessive nerve connections. There are many potential ways to develop treatment medications to reduce problematic nerve connections. Based on the expected results of the proposed study, such medications could become entirely new methods to treat OCD and OCD with clinical depression.