Inclusion criteria for ANS BROADEN study

• Have been diagnosed with major depressive disorder (MDD)
  
• Are between 21 and 70 years old
  
• Had your first depressive episode before age 45
  
• Have tried at least four treatments in your current episode; for example, different medications, different combinations of medications, and/or ECT
  
• Are open to considering a surgical option for your depression
  
• Are willing to get copies of your records from your psychiatrist for the last few years 
  
• Are available for follow-up visits for 12+ months
  
• Are willing to transfer your primary psychiatric care to the study psychiatrist.