In short, yes. My personal story is one of almost pointless therapy with diagnosis of dysthymia and depression that lasted through almost 2 decades, no better, no worse, just living with a ball of anger inside, living with people that had learned to be cautious and sympathetic and supportive, living one day and it's unexplainably unbearable frustrations at a time.
I knew I had finally found the therapist that was going to help me when the right questions were asked, and the right buttons were pushed, and I had an actual CHANGE in my general mood. It was worse than it had been by a power of 2 or 3, but it was a reaction, an actual effect from therapy after years of nothing but side effects.
The diagnosis was made and the path was charted and I am working through it, already much better than
I had been for so long, but my awareness of how damaged I am is much clearer now. I can see that I will never be "normal", but I will also not feel like this forever, and I have no idea how much better I can become.
You are a lifesaver if you can get this man through the worst of this, an Angel if you stick it out and make his damage a facet of your relationship that you both learn to live with. I am so grateful to my wife, I owe her my life as surely as if she had talked me down from a ledge or thrown me a rope before I drowned.