I've been on it for a year. I've taken multiple antidepressants and trintellix is the only medicine that has worked this well. I still have my dips but they don't last as long and are not as low as previous episodes. That being said, I started on 10 mg and have since moved to 20mg and my doc just added wellbutrin back to the mix after a really bad episode I just got out of, but we are thinking with the season change and holidays it was bound to happen and it's the first bad one in quite a while. I've been really off balance lately and I've had vision issues which I believe can be side effects but I can't attribute those issues to the med specifically. I haven't had any other side effects like weight gain or headaches.
Overall, I feel like I've made more progress with this then any other meds I've taken.
Good luck!