I'd say the depression has been ongoing for some time, and he stopped taking his medication several months ago (not sure on the exact number of months because I didn't fully realize it until after he had gone to stay with his mother).
He has not been exercising, has not seen a doctor or counselor, and has not resumed any medication. He has lost about 35 pounds and told me tonight about his poor sleep patterns. It could not be more obvious to me, but I didn't dare mention it to him.
I can tolerate it as long as I have to. I told him tonight that I was okay with things being in a holding pattern. I also made it very clear that I did not want a divorce and would not go merrily along with signing anything that dissolved our marriage.
Though I've been frustrated and likely will be again, I am an incredibly patient person. I'm more patient than most people, and my job has also helped me acquire a seemingly endless supply of patience. I can go as long as he can.