While I'm probably not qualified to speak for cptsd, as I've not been officially diagnosed with it, I do know that many MH issues will by themselves, and in culmination create problems as far as depression is concerned.

By the nature of the problems we face, they all interact with each other and have a knock on effect.

So far the only thing that has helped me has been trying to regulate my sleep more, as well as medication for my depression. As yet therapy has had no long lasting affect.