DBS of the Lateral Habenula in Treatment-Resistant Depression

Inclusion Criteria: * Men and women (non-pregnant) between ages 21 and 70; * DSM-5 diagnosis (assessed by Structured Clinical Interview for DSM-5, SCID-5) of a current major depressive episode (MDE), recurrent or single episode with first episode before age 45, secondary to either nonpsychotic unipolar major depressive disorder (MDD)or bipolar disorder (BD) I; * Chronic illness with current MDE ≥ 24 months duration and/or recurrent illness with at least a total of 4 lifetime episodes (including current episode ≥ 12 months); * For subjects with a bipolar disorder: the last manic or hypomanic episode must have been ≥ 24 months before study enrollment and patients must be maintained on a mood stabilizer (e.g. lithium or another mood stabilizer approved for bipolar disorder). * Treatment resistance (defined by criteria on the Antidepressant Treatment History Form): Failure (i.e. persistence of the major depressive episode) to respond to a minimum of three adequate depression treatments from at least two different treatment categories (e.g. SSRI's, TCA's, other antidepressants, lithium-addition, irreversible MAO-inhibitor, antidepressant augmentation with an atypical antipsychotic medication); also, if diagnosed as bipolar, failure to respond to (or inability to tolerate) a minimum of three treatments approved for bipolar disorder, including lithium and at least one medication FDA-approved for bipolar depression (e.g., olanzapine/fluoxetine combination, quetiapine, lurasidone). *…