OCD affects 2-4% of people and ranks seventh among the most debilitating illnesses worldwide, yet compulsions paradoxically strengthen obsessions rather than relieve them. This episode explains the cortico-striatal-thalamic brain loop underlying OCD and details evidence-based treatments including exposure-based cognitive behavioral therapy, SSRIs, and emerging approaches like transcranial magnetic stimulation and inositol supplementation. Compulsions provide only brief relief from obsessions but reliably strengthen the underlying obsession, creating a self-reinforcing cycle that worsens OCD over time.