The SSRIs are very effective for the type of depression seen with PD. There have been case reports of PD worsening with prozac and one report with paxil. There was a study done in which patinets were evaluated before and after starting prozac 20 mg in a prospective fashion. There was no worsening of PD by the rating scale.The differences are in the side effects and the half-life.Prozac has the longest half-life and if a side effect develpos, it takes longer to be eliminated. There have been recent warnings about combining SSRIs with elddepryl and this should be discussed with your M.D.