Maybe I can try to answer that with what's already known.
There were studies done about personality disorders and stress exposure in life as a factor leading to or increasing the risk of Alzheimer's disease. There's no convincing data to that effect. Perhaps it's fair to say that if you are predisposed to a disease because of your genetic makeup, you will have the symptoms at an earlier stage if you had head injuries, if you were drinking alcohol too much, if you had hypothyroidism.
So there may be accelerating factors to a disease that you will get someday. That's as far as I think we can go with the evidence.