I sympathize very much; I also have a sister with the same disorder and I know how difficult the illness can be. I agree that your own health and safety must be your top priority and, since you've observed that giving into her imperious demands or threats does nothing to help, setting clear boundaries about what you will and won't do is equally important. Look, you start off by describing all the ways you've tried to help that she refuses and then you ask, once again for some ideas, as if there's some key to your sister's illness that you simply haven't found... There is no simple key, no easy answer. The problem is that you, yourself, can't help your sister- that is, not until SHE decides to acknowledge that she has something she needs help with. Even then, only she can decide to go to the doctor, take medication despite side effects, decide that there's more to life than what she's got when she's acutely delusional..... Your role right now may be to be clear to her that you love her and hate to see her suffer, but you also recognize that she will make her own decisions about her treatment. However, you won't allow abusive phone calls, you won't be rescuing her when she throws good things away, and if she threatens herself or you or anyone else, the threat alone is enough to get the police involved; she must not be allowed to frighten you to get her way... If the police come she may end up in a hospital where treatment can commence anyway... It's a difficult thing to do with a sibling, believe me, I know, I've done it time after time. But that my sister is much better now is the hope I can offer you. There are many non profit organizations out there to help as well and many books on the subject of schizophrenia including memoirs from family members- I'd recommend reading some... Just remember, it isn't your job to stabilize her- just be her sister and set limits reminding her that you do so because you love her. That's my best advice as a sister.