My friend told me yesterday that she has the beginnings of PD. Her mother had it. She is bipolar. I asked her how she knows, and she said her doctor told her because of her mother and her dopamine levels are low and her hands are shaky. Is this really a definitive way to diagnose PD? It just didn't sound right to me for some reason, but I have no prior experience with this disease. Are there conclusive tests that can determine this condition? Can certain drugs cause these same test results? I believe she is on a number of meds for her bipolar condition. I was also told that being bipolar her chances of having this is increased. Any info would be appreciated.