My boyfriend is being affected by this right now. He is trying to kick cocaine use. He was using everyday, and in this last month he has used only a couple of times. Before he started to quit, he was doing a lot of research, and we talked at length about how this would happen to him. The decrease in dopamine causes depression. He also has anxiety, and he has trouble sleeping. His new doctor says he needs to let his body readjust on its own over time for the most part and it will get better. There are also some medications that he can use, but he wants him to wait if possible.
I have been calling his mood swings, like extreme PMS !! (I havent said this to him, but it is what I use to help me relate).
Its really great your husband is going through a full exam. Sounds like he has a good doctor. I hope they come up with a treatment plan that works well for him.