I've been on mirtazapine coming up for 6 years. I was on efexor [not the best med for me] a year before that. Though I was depressed many years preceding, I hadn't sought help for various reasons. I did reduce the dose for a year, with professional support, with a possible view to coming off it, but then things at work got really insecure, and still are, so my GP increased the dose back up and I'm not keen to come off any time soon.