My PDoc suggested it a couple of years ago after I tried two meds for depression that did not work at all. I was reluctant at first, but the company she used had a sliding scale for the cost, and I went ahead and did it. Sure enough, the two drugs she started me on were in the "not very effective" category. So, we started on the list of recommended meds.

I was hopeful that at least one of those drugs would help me, but ultimately it turned that I have treatment resistant depression. If you can afford to get the test done, it may well be worth it just so you don't have to wait as long (assuming one works for you) to get the benefits. Good luck!