From The Quarterly, Winter 2012
Obsessive-compulsive disorder (OCD), the most severe of the anxiety disorders, is characterized by recurrent, intrusive thoughts or obsessions—irrational fears of danger, illness or germs, for example—and repetitive, ritualistic behaviors and compulsions, such as constant hand washing. The symptoms of OCD generally begin manifesting in childhood or adolescence, suggesting that there may be something abnormal occurring during the brain’s development.
The posterior medial frontal cortex (PMFC) and the ventral medial frontal cortex (VMFC) are regions of the brain that have been found to be hyperactive in people with OCD. In tests that Dr. Fitzgerald and her team conducted with OCD children and normal controls performing cognitive tasks, the OCD children performed correctly, but imaging studies showed that their brains had to work harder to filter out distracting information to get the correct response—they had too much activity in both regions. In the resting state, the PMFC was insufficiently connected to a posterior part of the brain important for task control. For both filtering out distracting information and responding to errors, the VMFC was activated in the OCD children, when it should have been turning off. The VMFC, too, was abnormally connected within brain networks.
A next step will be to study larger numbers of children with OCD at each age, following them to see how their brains change over time. This is especially important because recent studies suggest that OCD may, in some cases, remit. With good treatment, in particular cognitive behavioral therapy (CBT), with or without medications, up to 40 or 50 percent of OCD children get better. A particularly effective form of CBT for OCD is what is known as exposure and response prevention. There are also good medications, but many people have to go through three or four different drugs to find one that works for them.
What is not known as yet is how to predict which people will get better. If it becomes possible to characterize the brain, and how development may be going awry in the particular regions or networks of brain regions to give rise to OCD, it may be possible to use imaging tools to predict who is at risk for developing the disorder and to come up with early interventions and possibly preventative measures.