CASC: Negotiate first ERP session for contamination OCD

Candidate instructions

You are the psychiatry registrar. Priya, 31, has contamination OCD on sertraline 150 mg oral daily with partial benefit. She washes after any outdoor contact and her partner answers "are my hands clean?" many times daily. She is anxious about "making OCD worse" with exposure. In 10 minutes:[13]

1. Explain ERP rationale in plain collaborative language.
2. Negotiate one concrete first exposure with a clear response-prevention rule.
3. Elicit predicted outcome (expectancy) and how you will review learning.
4. Address partner accommodation without shaming.
5. Set between-session homework and a brief risk/distress plan.
6. Avoid becoming a reassurance ritual yourself.

Actor brief (Priya)

• Wants help but fears germs and "losing control" if she stops washing.
• Will accept a door-handle or phone-touch task if rationale is clear and graded.
• Presses for reassurance ("But it is safe, right?").
• Partner accommodation is a point of conflict at home.
• Opens up if collaborative; freezes if lectured or forced.

Marking grid (domains)

Model process (time map)

0–2 min — Engage. Agenda: OCD treatment options; permission to discuss a first practice today. Validate disability and effort on sertraline.[13]

2–5 min — Rationale. Obsession → distress → wash/reassure → short-term relief → stronger OCD. ERP deliberately blocks the relief step so the brain can learn a new outcome. Evidence base is strong (name EX/RP trials if asked).[1][3][13]

5–8 min — Negotiate task. Example: touch shared door handle, then no washing/sanitiser for two hours; no reassurance questions. Rate predicted catastrophe 0–100. Stay present with urge; if wash occurs, re-touch after. Partner script: "I care about you, and I will not answer the clean-hands question; I can sit with you."[12][13]

8–10 min — Homework and safety. Two home practices; log distress and whether rule was kept. Brief SI/self-harm screen; plan for if distress spikes (contact supports/clinic/crisis line) without using washing as the only coping tool. Book review; mention Y-BOCS tracking over the course.[14]

Sample high-scoring utterances

• "ERP means we practise the trigger and we practise not doing the ritual that usually shuts the anxiety off."
• "What does OCD predict will happen if you touch the handle and do not wash for two hours?"
• "If I keep saying 'you're safe,' I become part of the ritual — I will help you sit with uncertainty instead."
• "Your partner's reassurance is loving and also accidentally feeds OCD; we can give them a kinder script."

Common station fails

Lecturing about serotonin only; forcing top-of-hierarchy tasks day one; providing repeated safety reassurance; no response-prevention rule; ignoring partner role; promising zero anxiety; recommending risperidone as the first next step without offering EX/RP.[3][13]