Wow, this got away from the original question. Yes, I do believe that the treatment of people under the spell of the JW society can absolutely influence one to develop something like a borderline personality disorder, or I believe today it is called something like "emotional dysregulation disorder". Let's face it, the cult both attracts people with various mental illnesses and creates it on the back end. BPD is just one of many.
I was listening to a podcast the other day and this guy that has struggled mightily in life was describing his horrible childhood and his mother who eventually "broke" and then, you guessed it, it came out that she was a JW. His dad would have the elders over to rip them about what they were putting in his wife's head. She was terrified of Armageddon and that her husband and son wouldn't be with her in paradise. She was eventually diagnosed as schizophrenic, and her life ended prematurely at her own hands as she couldn't bear the paranoia and delusions anymore, encouraged by JW teachings. So sad, and sadly not a one time occurrence.