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ERP for Symmetry OCD — MRCPsych Paper B MCQ

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ModerateAnxiety & Stress-Related DisordersERP for Symmetry OCDMRCPsych Paper B

A 26-year-old with obsessive-compulsive disorder repeatedly realigns objects until they feel “just right”. Leaving objects misaligned causes marked distress, but they do not fear contamination or a specific catastrophic consequence. Which exercise best exemplifies exposure and response prevention targeted to this symptom dimension?

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Reveal the answer and explanation

Correct answer: A — Deliberately leaving objects asymmetrical and refraining from rearranging them

Explanation lettering: B = shown as A · E = shown as B · A = shown as D · D = shown as E

The correct answer is B. ERP requires exposure to the trigger for the person’s obsessional distress while preventing the associated compulsion. Here, the trigger is asymmetry or a “not just right” experience, and the maintaining response is repeated arranging. The appropriate exercise is therefore to create or tolerate asymmetry without correcting it. Contamination exposure with prevention of washing (A) targets contamination/cleaning OCD. Imaginal exposure (C) is particularly useful when treatment must address an intrusive feared outcome or covert mental ritual, neither of which is described here. Social exposure with removal of safety behaviours (D) is characteristic of treatment for social anxiety, while interoceptive exposure (E) principally targets feared bodily sensations, particularly in panic disorder.

Reference: Royal College of Psychiatrists. Obsessive-compulsive disorder (OCD), sections “The components of OCD” and “Exposure and response prevention (ERP)”. Current webpage accessed 19 August 2026. https://www.rcpsych.ac.uk/mental-health/mental-illnesses-and-mental-health-problems/obsessive-compulsive-disorder