This study will report on the outcome of a clinical program, operational since 1998, that has used surgery targeting an emotional pathway in the brain in the treatment of severe depressive illness that has failed to respond to all other available interventions. Benefit from surgery was anticipated on the basis that the lesion (bilateral anterior capsulotomy) is a well established surgical target for treating severe treatment resistant depression.

Since 1998 bilateral anterior capsulotomy (BAC) has been available to patients in British Columbia Canada who have treatment refractory severe depressive illness. This study will report on the outcome of patients who have received this intervention. BAC is achieved by stereotactic radiofrequency lesioning. To date 8 patients have received BAC. For all patients there is follow-up data of at least 24 months. The purpose of this retrospective study is to report on the surgical protocol and to demonstrate the efficacy and safety of BAC in severe depression.

Inclusion Criteria:

• Severe treatment resistant depression of at least 5 years duration
• older than 18 years

Exclusion Criteria:

• Comorbid organic mental disorder
• Delusional disorder
• Substance disorder
• Neurological disease
• Cluster B personality disorder

All subjects who received BAC for treatment resistant depression between 2000 and 2009