The objective of the BROADEN (BROdmann Area 25 DEep brain Neurostimulation) Study is to investigate whether or not stimulating a structure in the brain known as Brodmann Area 25 (BA25) with a deep brain stimulation (DBS) system is safe and effective for MDD.

Participants in this study must

• Meet the inclusion criteria
• Have surgery to have the DBS system surgically implanted
• Be available for follow-up visits for 12+ months

Participants should continue to take their current medications and participate in counseling during this study, but their psychiatric care must be transferred to the clinical study team for the 12-month duration of the study. Participants will receive the device, the surgical procedure, and study-related follow-up care free of charge.*