Grace, they don't casll this the "snowflake disease" for nuthing! I t has to do, I suspect with every person's brain chemestry being different...therefore we all get PD at different times in our lives, with all sorts of varying symptoms and each react to meds in a different way. I think that you hit the nail on the head when you asked how can they be sure that it's PD? Well, sometimes they can't. I have a grilfriend who was dxed as mentally incompetent for insisting that there was something wrong with her-despite drs. being unable t o come up w/ any reasons for her. She ended up on the psych ward of a local hospital, doped beyond belief until someone came up, quite by accident, with the correct dxes. That is one of the reason's why we must be visible and vocal about our disease-to let our friends and family and the lady in the framing store and the idiot (who like I used to) will stand behind me in the check out lane, rolling his eyes and tapdancing while I'm trying to write a check and get the money back into my pockedt-no time to recount the change. I look at him with one of my practiced grins and say: "You know, I used to hate people like me ...until I became one. You'd better be careful because God sure has a sense of humour when it comes to teaching us lessons!!!" Correct me, if I'm wrong (which I have beem known to be), but isn't PD like Alzeheimer's? There is no one certain test for PD, I think that it's more of a process of elimination and waitng until thed symptoms more fully manifest themselves so that a diagnosis can be made more surely. Another way they use is your reaction to simemet. If it works-you can be pretty sure you got it. I took sinenmet for a year and a half beforefinally going to Mayo to be dxed. No surprise there-I figured that if it walked like PD & it quacked like PD then it must be PD! I hope this letter doesdn't confuse you all the more as I have been known to do that also!! Best of luck in your journey forward, Joan -- Joan E. Snyder 48/10 [log in to unmask] <http://www.newcountry.nu/pd/members/snyder/page1.htm> "Life does not have to be perfect to be wonderful." Annette Funicello