I read that over 65% of children with BPD will develop either Alzheimer’s Disease or Parkinson’s Disease as they grow older. Can’t remember the source.
I can’t say for sure this is correct, I can only explain it how I understand it.
One thing that I think of is the fact that people with BPD tend to also have a high rate of substance abuse, which can impact memory and the nervous system. Many people with BPD have very poor memories (not my case, though, I have a near photographic memory, though some medications harmed my short-term memory while I was on them). This makes me think that it’s possible some BPD medications negatively affect memory. There isn’t just one medication specifically for Borderline, however when you have BPD you are prescribed a series of medications that can alleviate certain symptoms.
Another reason is individuals with BPD might not take care of themselves. This is because many with BPD dislike themselves. A poor diet plan and poor sleep actually can be reasons for future illnesses, which poor sleep is really connected to dementia.
Trauma might also be a cause. We know that many people with BPD are victims of abuse. Trauma affects our nervous system, and even it can impact our memory, which is why people with traumatic experiences tend to develop PTSD. PTSD is tied to our memories in a way.
Also, in people with BPD the amygdalae and hippocampuses can function differently or have different shapes. The amygdala is our emotional guideline and clearly impacts the nervous system in some ways and the hippocampus is the memory place. Neurodiversity perhaps tells us something; perhaps the ways in which a BPD brain is wired makes it more vulnerable to dementia or Alzheimers.