Jen-
They have found out that most of the SSRI's and other AD's do have withdrawal effects if stopped abrubtly. Effexor is a good medication, I wouldn't hesitate to use it. I was on it a long time ago, when it was only available in short acting form. It worked well, and then stopped, but that happens to me on all of them. The key is to never stop any AD's abrubtly, instead tapering down on the dose slowly, as your doctor should advise you. Hope this helps. HUGS!