If someone you care about has BPD you will find yourself challenged and provoked. Your loved one will often be uncertain whether to idealize you or devalue you. One moment you are her favorite relative or best friend, the next moment you are being accused of being unreliable and hateful. You will be exasperated by these swings in her view of you. It is best to be honest about your feeling s but also to try to be calm in your response so that the accusations do not escalate. If you respond to her hostility by becoming sarcastic or critical, then you will have played the role she laid out for you. You may find it helpful to be a little unpredictable yourself. If she expects you to be saintly, admit that you are upset. If you find yourself becoming enraged, then take a break to calm down. Above all try to maintain your equanimity.
You may also feel that your loved one manipulates you by making demands and threats. She may deman that you spoend less time with others. She may threaten to stop being your friend, or to harm herself. You should decide what sort of behaviors you are willing to tolerate and be clear about what you aren't willing to do. If you are calm, consistent, and supportive when setting limits, and if you set them ahead of time, your loved one may feel less rejected. you should not panic hen she expresses from time to time a desire to harm herself. You may want to let her know that you are willing to listen to her when she feels like hurting herself, but, if talking will not help, you are prepared to call an ambulance or to take her to the hospital yourself. When dealing with any impulsive behaviors you want to encourage her to take responsibility for the choices she makes, rather than taking on the role of monitoring and rescuing her.