I think we are confusing "mental health or illness" with "dementia"

Dr. Laura Marsh (formerly at Johns Hopkins; now at the Houston VA), a well-known and respected psychiatrist who specializes in PD and traumatic brain injury thinks that PD should be categorized as a "neuropsychiatric" disorder. In general, this means that most cases of PD are not only defined by motor symptoms, but also usually by some sort of mental component such as depression and anxiety (among many others).

Neuropsychiatric Aspects of Parkinson's Disease, by Laura Marsh.

I don't think this precludes continuing to work - even as a physician. It just means we need to pay attention to ALL potential symptoms. Dr. Marsh is always saying that if depression or anxiety is identified, then there is real help to recover from those conditions - a much better opportunity than there is to recover from other symptoms. And she knows that if you can get your mental health together, your physical health will benefit as well.

I can't comment on what is happening with the woman with Texas, but I do think it can be said that Parkinson's affects your mental health - in different ways in different people - just like all of the other symptoms. No two of us are alike!