AC, one thing I've noticed we have in common is our Ws are dealing with depression. Unfortunately, it adds an extra dimension to this. I think we are the last ones in the world to get them to get help. I think in my case my W believes are M is the direct cause for her depression, and doesn't see the need to get help. In my case it's hard to tell whether it's a clinical depression, situational, or a combination of the two. In my case, I think it may be a combination of the two.
The good news is a lot of the techniques are the same in DB'ing, as far as detaching and GAL'ing. I think it just makes it more of an uphill battle. Hopefully by getting some space your W will seek out some help.