My Dad has PD for 7 years now and I think it has impacted his personality tremendously. It seems difficult to sort out the chicken and the egg here but living with a degenerative illness has brought so much anxiety, fear and overwhelm. As he declines cognitively, I've also seen so many personality changes. All of the things about himself he was most proud of are lessening rapidly and it is like a windfall of anxiety and depression. Add to that the physical challenges and he is more socially withdrawn than ever too. Also, in my work, I support people who are dying and grieving, so I see how grief impacts our personalities and I suspect a lot of what I'm seeing is grief. Hope it helps to know you are not alone. Hugs.