Hi I also take mirtazapine 45mg but as an add on with lithium 1,000mg. I'm not sure how long I have been taking mirtazapine probably about fifteen years. Lithium nearer twenty years. Prior to that I was a long term dothiepin junkie on high doses 175mg. I couldn't tolerate any more although it was tried. I came off it virtually cold turkey but cleanly with few side effects. I also tried seroxat which I could not tolerate. I have seen my psychiatrist recently and he is happy for me to continue with this regime.