"i was put on mirtazapine by my doctor recently and the side effects of it were horrendous. slept for hours on end, when i did get up i was living through a fog. i couldn&#039;t function on a day to day basis. the nightmares were awful, vivid very scary dreams that i couldn&#039;t force myself to wake from so i decided enough. i had been on citalopram before that and it was no longer helping so i was switched to the mirtazapine. i went back on prozac and in less than a week i feel better, my head is clear and i can do things i enjoy. i don&#039;t sleep well anyway so the prozac has no effect on that. i will stick with the prozac."