Why is setting boundaries with a person with Borderline Personality Disorder (BPD) so difficult?

​Healthy relationships are based on behavioral boundaries that are understood and respected by both parties. Individuals who suffer from BPD are offended by your efforts to set boundaries with them. Their resistance to this process is a major factor in causing their relationships to be unstable and unsatisfactory to them. Understanding why this is the case requires an understanding of how having BPD inhibits the ability to understand boundaries and to use them to strengthen relationships.
 
Boundaries are expressions of what we need to feel safe and comfortable in relationships. This may include how you feel about being touched by another person, what you like to be called (e.g. Robert, Rob, Bob or Bobby, etc.). Safety and comfort are necessary for intimacy. The wish to be intimate is a motivation for respecting boundaries.
 
Healthy individuals understand that setting boundaries is a process of relationship building and they appreciate the opportunity to make you feel comfortable. They do not mind, not smoking in your house or not calling the home phone after 10 PM on weeknights. They feel privileged when you say “My friends call me Bobby” and are happy to comply with these boundaries.
 
Sufferers of BPD see your setting boundaries with them as a form of rejection. It makes them feel bad about themselves; less than. They believe that if you love them you will tolerate any and all behavior on their part to prove it. BPD causes sufferers to need constant reassurance from others that they are loved. This need causes them to test others in various ways to get them to prove their love and commitment. One core testing behavior is the challenging of personal boundaries. Seeing if you will speak to them at 2 AM because that is when they want to talk, even though you asked them not to call that late because you get up early for work in the morning, is such a test. The first part of the test is whether or not you pick up the phone. If you pass the first part, then the second part is whether or not you are angry. If you fail the first part you will be punished the next time you do speak. You will be accused of not being available in an emergency and of not caring. If you do pick up the phone and you are angry, you will be accused of being unloving and unsympathetic. The only way to pass the test is to allow them to violate your boundary and be nice about it!! Once you do this, the boundary will be retested. It will be assumed that since you relaxed the boundary once that you will relax the boundary whenever they wish to talk. They will then assume that you will relax other boundaries as well, leaving you feeling like you have no ability to set any boundaries at all.
 
Setting boundaries with individuals who suffer from BPD requires your understanding that boundaries will be tested and preparing for this to occur. Setting boundaries successfully with sufferers of BPD will require the following elements:
 

• The boundary must be clear. Individuals with BPD must be told that calls are not taken after 10 PM on weeknights. It is not sufficient to ask them not to call “too late”. They will argue that 2 AM is not too late for them.
• The boundary must be consistent. Since the boundary will be tested, it must be made clear that there are no exceptions. If asked about an emergency, you tell them to call 911 in emergency. That is what you would do anyway. Other matters can wait until morning.
• The boundary must be presented without anger. If you express anger towards them it will allow them to feel victimized and they will use it to justify both their breach of boundary and their reacting by punishing you.

 
The following dialogue will illustrate how to set a boundary around calling your home too late. The friend with BPD was asked not to call after 10 PM on weekdays but did so anyway to “test” your love and commitment.
 
Friend: “Why were you so nasty with me on the phone last night?”
You:    “I asked you not to call after 10 PM on a weeknight.”
Friend: “It was only 11:30.”
You:    “I just need to get some sleep before I go to work in the morning.”
Friend: “Oh, I am sorry I interrupted your precious sleep. I won’t call again without an appointment.”
You:    “That is not what I said. I am simply asking for some consideration.”
Friend: “Don’t worry, I won’t be calling you anymore. You can sleep as much as you like and call me if you want to speak to me.”
 
At this point the topic should be ended. The point should not be argued, because this suggests that the point may be negotiated. Boundaries must be consistent and therefore cannot be negotiated. You can try to change the topic and continue the conversation, but if the friend continues to try to punish you then you must end the call and try again at some other time to have a conversation with this person. If the friend subsequently calls during daytime hours you should pick up the phone and be pleasant. If they call late again you should not pick up the phone. Eventually, the friend will understand that they must respect your boundary if they want to have a relationship with you. Healthy individuals accept boundaries respectfully. Individuals with BPD must be forced to respect boundaries.