I started Prozac last December at twenty milligrams and then went up to, where I am now, fifty-five milligrams. To-day is week six of being on this dose, and I just feel down, and not happy. I heard that it takes six to eight weeks to kick in, but I'm just wondering if I can expect anything to get better with time. I see my psychiatrist in two weeks. I have ocd and heard that it can take high doses of an antidepressant to work on that. I think I have anxiety related ocd.