Buprenorphine Used With Treatment Resistant Depression in Older Adults

slow titration up to maximum dose of 300mg per day, will remain on venlafaxine XR for up to 32 weeks

randomized to either buprenorphine or placebo, dose range from 0.2 mg/ qd to 2mg/ qd

patients will remain on venlafaxine XR and be randomized to receive either placebo or buprenorphine for 8 weeks. at the end of the 8 weeks those who did not receive buprenorphine will be offered the opportunity to try it.