I have been on Depo Provera for quite a while... I haven't had a period in several years. I LOVE not getting my period, and I actually found that the particular hormones in Depo have made me less emotionally "flighty". I think it is often estrogen that is responsible for mood swings, and Depo is progestin-only. I'm a big fan, although I know it doesn't work for everyone. There is a low-dose version now as well.