The Efficacy and Mechanism of DBS in VIC and NAcc for Refractory OCD

Inclusion Criteria:

1. Diagnosis of OCD with duration of at least 5 years;

2. Severity rated as severe to extreme illness;

3. Failed adequate trial of at least three specific serotonin reuptake inhibitor (SSRI)antidepressants;

4. Failed augmentation with antipsychotic;

5. Completed or failed to complete adequate trial of cognitive behavioural therapy forOCD;

6. Stable medication regimen for one month before surgery;

7. Signed informed consent;

Exclusion Criteria:

1. Hoarding as a primary symptom;

2. No other serious psychiatric disorder such as psychotic disorder;

3. Drug or substance use disorder within 6 months except nicotine;

4. Major Neurological/Medical condition;

5. High suicide risk;

6. Pregnancy or lactation;

7. Contraindications to stereotactic surgery;

8. Contraindications to MRI;