Quote: "As it turned out, 8 of the 12 patients he operated on, including Deanna, felt their depressions lift while suffering minimal side effects — an incredible rate of effectiveness in patients so immovably depressed. Nor did they just vaguely recover. Their scores on the Hamilton depression scale, a standard used to measure the severity of depression, fell from the soul-deadening high 20's to the single digits — essentially normal. They've re-engaged their families, resumed jobs and friendships, started businesses, taken up hobbies old and new, replanted dying gardens. They've regained the resilience that distinguishes the healthy from the depressed."
I hasten to add that DBS is nowhere near ready for the clinic -- it's experimental and risky. But it shows what can happen when people are willing to consider biological explanations instead of psychological ones.
Because the Hamilton Depression Scale only measures symptoms and doesn't address the issue of causes (theories), no, it isn't. And the linked study will have to be repeated very carefully, with more patients, before it will be accepted as a treatment.
And finally, regardless of its value as a treatment, that study can only be a steppingstone toward actually understanding what depression is, in a biological, scientific sense.
There have been some promising studies showing rapid-onset relief for major depression following the administration of ketamine. Glutamate seems to be getting more attention these days, in terms of its potential role in mental illness.
