Hello and

Your questions are actually pretty deep. Good questions, but scientists still have lots to do before they fully understand brains & individuality. Some people are vulnerable to heart disease, diabetes, eye disease, the list goes on (and on). Weakness to many conditions are genetic. But, just because a person is weak to a genetic disease does not mean that they are guaranteed to develop that (or those) illness/es. They simply need to keep their eyes peeled, so to speak, for symptoms and live their lives healthily.

If a person has a genetic weakness to developing diabetes, they'll have to watch their diets and general feeling of health closely.

The knowledge of the personality disorders are certainly more vague than the highly studied diseases, like diabetes. However, they have been (and are continuing to be) studied. It is tough to make definite decisions when there are some unknowns. Doctors usually look at cases individually nowadays, because they are beginning to understand how individual human health is.

The brain is much more involved in development and progression of disease/s than previously believed. Like any science, there are people all over the board in their hypotheses as to how the brain is so involved in our physical health.

In my opinion, the individuality of diseases will continue to occur. We aren't all the same. General trends ~majorities~ are there in how or why, and minorities not fitting the trend are there for other reasons.

I feel as though I talked in a big circle here . Hope that it makes sense to you! Best wishes to you

Shez

ETA: I do have temporal lobe epilepsy, from a high fever as a baby. Also fit general description of emotional reasons for development of BPD. Did have surgery 3/06 on my left temporal lobe, to remove epileptic foci, which made my BPD symptoms much stronger.