Note: Please don't take offense, OH. I love you dearly; I'm just frustrated that you're still in the same spot. Maybe I'm so frustrated because I, too, am in the same spot, having let my weaknesses rob me of my cajones.
That said, I agree OH needs to make up her mind and stick to it, and that her inability to be (or fear of being) firm about what she needs is keeping them from reaching any sort of resolution.
I do understand depression as I've been battling it for over 10 years, with the off and on (currently on) help of medication; it's only because of my stubbornness that I am still alive.
I simply disagree that he doesn't understand what's going on. He has a severe issue of wanting to be a big player and being unwilling to be anything but
that - most likely out of low self-worth and toxic shame (fear of being found wanting). And the fact that he has been financially supported by OH for over 10 years has allowed him to AVOID the reality that anyone else crippled by depression would have had to face by now.
Which is why I have, over and over, asked her to consider leaving him just SO he can be forced to get the help he needs, if only for financial reasons. She stood up to him once, and as I recall, the one thing she asked of him (which many of us asked her to reconsider) was just to talk
to SH. Not to work to get better, not to attend X many therapist visits, not to get on ADs, but just to talk to SH. I'm sure she was hoping that her DH would 'get it' like so many other people seemed to.
So, easy enough. He agreed to it. She'd back down and all he had to do was talk to SH. He did. She backed down. He got what he wanted, which was to get her to leave him alone and keep supporting him so he didn't have to brave the real world.
I'm not saying he was specifically thinking those words. Between his depression and his drinking, probably not a lot of clear thinking going on. But he's on autopilot and does what works for him. As OH knows, only by HER changing at this point, will HE change, out of necessity.
So, if all OH is willing to do is tell him "I'm going to leave you by Dec. 31 if you don't start attending weekly therapy" - I'm fine with that. At least it's a change. He'll never get better without some form of change. At least we can agree on that.