A 32-year-old man with a 5-year history of OCD (contamination obsessions and checking compulsions) has been on sertraline 200 mg daily for 8 weeks with minimal improvement in symptoms. Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) score remains 28 (severe). He is compliant with medication and denies comorbid depression or substance use. What is the most evidence-based next step in management?

Explanation

## Treatment-Resistant OCD **Key Point:** After 8–12 weeks of adequate SSRI dosing with poor response (Y-BOCS reduction <25%), the patient has treatment-resistant OCD. The next step combines pharmacological augmentation with evidence-based psychotherapy. ## Management Algorithm for SSRI Non-Response ```mermaid flowchart TD A[OCD on SSRI 8-12 weeks]:::outcome --> B{Y-BOCS reduction ≥25%?}:::decision B -->|Yes| C[Continue SSRI + CBT/ERP]:::action B -->|No| D[Treatment-resistant OCD]:::outcome D --> E{Next step?}:::decision E -->|Option 1| F[Augment with antipsychotic]:::action E -->|Option 2| F E -->|Option 3| G[Switch to clomipramine]:::action F --> H[Add risperidone/aripiprazole to SSRI]:::action H --> I[Refer for CBT/ERP]:::action G --> J[If still inadequate, add antipsychotic]:::action I --> K[Reassess Y-BOCS at 4-6 weeks]:::outcome ``` **High-Yield:** Antipsychotic augmentation (risperidone 2–4 mg or aripiprazole 10–15 mg added to SSRI) is the most evidence-based next step for SSRI-resistant OCD, with response rates of 40–60% [cite:CANMAT Guidelines 2016; APA Practice Guidelines]. ## Why Augmentation + CBT/ERP Is Correct 1. **Pharmacological:** Antipsychotics (especially risperidone) augment SSRI efficacy in treatment-resistant OCD 2. **Psychotherapeutic:** CBT with ERP is the gold-standard psychological intervention; combined pharmacotherapy + psychotherapy yields superior outcomes 3. **Evidence:** Multiple RCTs support augmentation strategies over dose escalation or switching alone 4. **Timing:** Y-BOCS 28 (severe) warrants aggressive intervention; waiting for higher SSRI doses delays benefit ## Comparison of Options | Strategy | Evidence | Limitations | |----------|----------|-------------| | Augment SSRI + antipsychotic + CBT/ERP | **First-line for resistant OCD** | Requires specialist psychiatry; antipsychotic side effects | | Switch to clomipramine | Second-line alternative | Slower onset; anticholinergic burden; requires washout period | | Increase sertraline to 300 mg | Not recommended | Exceeds FDA-approved range; no evidence for further benefit; delays effective treatment | | Switch to fluoxetine | Not recommended | No advantage over current SSRI; delays effective treatment | **Mnemonic: RACE** — Resistant OCD: Augment with antipsychotic, add CBT/ERP, Evaluate at 4–6 weeks.