Definition and Pathogenesis

Obsessive-compulsive disorder is characterised by recurrent, intrusive and distressing thoughts, ideas or images (obsessions) that drive the patient to perform repetitive, ritualistic mental or physical acts (compulsions) in an attempt to prevent or reduce stress.^{3, 4, 5}

The exact aetiology of OCD is unknown, but research suggests that multiple genetic risk factors leading to altered neurotransmitter signaling or changes in cellular function that perturb fronto-striatal-thalamic circuitry (FSTC), may be associated with OCD.⁶ Abnormalities in serotonin (5-HT) neurotransmission...