My last major flare (it was awful, lasted months and left me with permanent damage) coincided with some bad life circumstances during which I was VERY sedentary. I suspect (can't prove obviously) that being sedentary was a major factor causing or contributing to the flare. Stress probably didn't help either, but that's beside the point I want to make.
Ever since then I try to walk for at least 20 minutes at a brisk pace every day. For some period of time I tried walking 2-3 miles per day, but it didn't seem to make any difference. I suspect, at least for me, that just keeping some level of activity every day helps keep me out of pain.
Just thought I would mention that in case you have been sedentary (because you mentioned depression and that can often keep us inside and sedentary).