I agree that there are times when you have to disengage from your spouse for your own safety - both physically and mentally. My husband and I have been together for nearly 11 years (married for 8) and we just went through this in a major way.
I won't go into all the details, but things were just bad for me mentally in the marriage. Over the summer, I finally told him I wanted a divorce because I couldn't do it anymore. I felt like I was slowly dying on the inside. He couldn't handle it and completely fell apart after he moved out and ended up at a psychiatric care facility.
Turns out, he was an undiagnosed manic depressive with severe depressive tendencies and had been for the last 15 years. Now that he's medicated...I just can't tell you the difference it's made. He's like a different person. Things are better than they've ever been or than I ever thought possible.
It's odd to think things wouldn't be this happy now if I hadn't disengaged from the marriage. I guess it can be a good thing in some cases.