Pathogenesis

Abstract Cortico-striatal-thalamic-cortical (CTSC) neurocircuitry plays a key role in obsessive–compulsive related disorders. Serotonin (5-HT), dopamine, (DA), and glutamate receptors in CSTC circuits appear particularly important. Particular variations in 5-HT, DA, and glutamate genes may contribute to vulnerability to obsessive–compulsive disorder (OCD). Immune mechanisms may also play a role in contributing to CTSC dysfunction. OCD may involve a failure to inhibit evolutionarily-based procedural strategies. Both pharmacotherapy (selective serotonin reuptake inhibitors) and psychotherapy (cognitive behavioural therapy) can reverse CSTC dysfunction.