I've actually considered that she needs treatment for borderline. I do think she probably has it since her whole life she has been pretty classically borderline. But the thing is, she's just going to quit therapy the minute she starts. So what's the point? She doesn't want to change her worldview and she does not have any idea that she needs help.

The things she say make me so angry. She says such ridiculous things and I am not allowed to criticize them! Last time we talked, she said, "I don't think anyone will understand my philosophy on life, because what I believe is that I need to destroy everything." Later she even said, "I want to destroy the world." As her older sister, am I supposed to just accept that? I ignore it but what I want to say is, "Are you crazy? This is not the way you live your life!!"