Probably because it's still experimental - trials are still ongoing at Toronto and Emory, and are still considered in the pilot phase. I don't think more than

Probably because it's still experimental - trials are still ongoing at Toronto and Emory, and are still considered in the pilot phase. I don't think more than 40 people have had it done so far, and it's definitely been more inconsistent in terms of effectiveness compared with Parkinsonism. That being said, you're right about the epidemiology - there's a lot of depression (and um....the potential market, which is how Medtronic, the company funding a lot of the studies, is looking at it). The appropriate clinical selection criteria for depression surgery, should it ever get approved by the FDA, will have to be carefully put together...