In obsessive compulsive disorder, the brain circuit representing certain behaviors fires over and over.
The OCD circuit is the brain circuit in the orbital frontal cortex and basal ganglia that triggers and maintains obsessive compulsive disorders. It includes the orbital frontal cortex, caudate nucleus and anterior cingulated gyrus.
In the OCD Circuit, neurons that project from the orbital frontal cortex and the anterior cingulated gyrus to the caudate nucleus are overactive and generate the persistent sense that something is wrong. The persistent sense that something is wrong is the result of a malfunction in the gating function of the caudate nucleus by allowing continuous prefrontal cortex stimulation.
In order to overcome obsessive compulsive disorder, the patient has to somehow modify the OCD circuit either by temporary (drugs) or permanent means (therapy). Cognitive behavioral therapy is an attempt to permanently rewire the OCD circuit by training the patient to choose and act on alternative, healthy behaviors. The patient can literally rewire her brain's "behavior circuits" by mindfully choosing alternative behaviors. Through repetition, the patient can weaken the OCD circuit and rewire her brain circuitry to regain control of her life.
Web Resources On OCD Circuit
Obsessive Compulsive Foundation
Book Resources On OCD Circuit
The Mind and the Brain : Neuroplasticity and the Power of Mental Force by Jeffrey M. Schwartz
Brain Lock by Jeffrey M. Schwartz