depression
"Horrible experience, although everyone is different. I was on 150mg, I am currently tapering off while switching to Welbutrin. With Effexor  tapering is necessary. I've tried going off cold turkey and the withdrawals are like nothing I've ever experience. I had intense brain zaps (google it), flu like symptoms, could easily sleep half a day away. Even if you miss one day, you experience these withdrawal symptoms. While on it, it only worked somewhat well for a month or so. I experienced light nausea which went away. I also experienced impotence and unable to climax which has not gone away. Now that I'm tapering and introducing Welbutrin the sexual side effects seem to be getting better."