depression
"After only five days on mirtazapine I thought it was amazing. I was diagnosed with severe depression and was at breaking point. I was reluctant to start taking Mirtazapine because of the negative reviews (weight gain, etc.).  The first three days were awful due to the heavy sedation effect, but that wore off sooner each day and by the fifth day I could function normally. In fact I felt loads happier and had tons of energy. Over the next six months I put on a stone in weight and so tried to come off it. But I felt dreadful with terrible insomnia, nausea and depression. I went back onto it after a week, having lost half a stone and have been on it for 18 months. I did not regain the half stone I lost and have controlled my eating better."