"been off/on antidepressants for 20  years. been on 100 mg of zoloft for about 5 years now and was having some adverse effects- gained a lot of weight for starters.  started pristiq about 3 weeks ago. i feel a lot clearer in the mind- guess i didn&#039;t realize the fog i was in on the zoloft. i&#039;m not hungry- lost seven pounds in the first two weeks. had some headaches while switching over. sleep hasn&#039;t been a problem- but i have found that i need to take the meds at the same time in the mornings or i have headaches. so far, so good. hopefully it will continue long term. i will probably be on meds the rest of my life- i&#039;ve come to terms with that. hoping this will be the last one i&#039;m on!"