For some people emotions won't set them back, but for me I believe the answer would be yes. I am on Paxil for an anxiety disorder. Before I started getting treated I felt like I had to be in control of everything or I was going to bust. I would eaisly get frustrated and irritated. I wasn't happy with that life. I spoke to my doctor about it and he suggested Paxil. I wasn't thrilled with taking meds, but I tried it because I was sick of living like that. My life has gotten so much better, I am happy and can let things roll off my back and I don't get so worked up over things.
While yes, SSRI's can cause you to gain weight the reason is mostly because it increases your hunger. I haven't had much trouble with it, I have lost 50 lbs in 7 months. (starting at 244).