I am taking 300mg per day of Zytram for severe Osteoarthritis pain. When my doctor stopped it & prescribed something else, I became seriously depressed, anxious & cranky within 3 days so I went back on Zytram. Zytram doesn't work extremely well for the pain but I am now afraid to stop taking it ever because of the deep change in mood. Has anyone else out there ever had this happen to them?