I am very atypical with depression and also treatment resistance too. I'm 59 and also have tried everything under the sun. What I found that works the best for me is Zoloft and wellbutrin. Far from perfect but the best results by far.

I also agree opiates also relieve depression and anxiety too! Any thing that addresses the central nervous system seems to work. I could even get by on a simple klonopin script for 2 x a day!

But it seems no matter what I take or how good it is, my depression always pops up as my anxiety does too.