Just letting everyone know that although I had some doubts about going on effexor for my anxiety disorder (gad), it has significantly helped (unless its a placebo effect, but doubt it).
I used to worry about having many diseases from cancer to aneurisms, even though I am only 22. I visited emergency rooms when there was nothing wrong at all. It seems like there is, and you feel you know there is, but for the most part there probably isn't. The feelings evoked from how I thought I had a disorder were debilatating. The effexor apparantly blocks these debilatating feelings which is so great. I tried zoloft a few years back and that really didn't do much for me.
I don't know anything about the withdrawal effects and I probably won't for a while because I don't plan to go off it anytime soon. There were some mild side effects (loss of appetite, slight nausea) when I started but they went away within 10 days.
It should be noted that I also took advantage of psychotherapy for a few months after starting the effexor. I heard that the combination of both significantly increases the chances of feeling better.
So 2 thumbs up for effexor! Good luck to everyone combatting anxiety disorders!! :d