I have had antidepressants "poop out". When it has happened I have switched antidepressant with great results. I was first on Paxil I got severe side effects and the it stoped working. I went though a terible withdrawl when I had what the drug companies call discontinuation syndrome. I went on Celexa and then lexapro. Lexapro stopped working and I am currently on Zoloft which has worked well along with Wellbutrin. I am also on Abilify which works great for me, but has made me gain weight that I cannot seem to lose even with daily exercise and diet. I hope this helped and I hope you find relief from depression soon.