I'm with the mindfulness approach; CT that is about changing the thoughts hasn't worked so well for me, but changing my relationship to them, YES. My own sense is that the negative thoughts are to such a large degree coming out of my slightly screwy biochemistry that I can't get too far towards changing them. But if I can understand them as to a large extent chemically-based, and keep applying as many reality checks as I can, and not get too caught up in the negativity, I can manage even when things are quite bad.