Hello Dakota1: I'm sorry you & your husband are having such a difficult time. I can only tell you that I'm in my mid 60's now. I've been struggling with my own personal demons my whole life. There have been periods during which I've been pretty stable. And then there have been times when I suddenly & unexpectedly went over the edge. I've been on various antidepressants. None of them did much for me. I've seen therapists. They ranged from unimpressive to dismal. I'm no longer on med's nor do I see a therapist. I've never had ECT.
I'm stable at this point mostly because, except for being married, I'm pretty-much entirely solitary. And being that I'm past retirement age, I no longer have to work. So, from my perspective, I would say that your husband's condition may fluctuate. He may have periods of time when he feels fairly good. But then there will continue to be times when he's close to, or over, the edge. I wish you both well...