Borderline Personality Disorder (BPD) causes significant distress, both for those suffering from the illness and for those suffering from having a relationship with someone who has it. Its symptoms are frequently misunderstood; specifically, many unfamiliar with the illness can't understand why someone would continually sabotage herself* or get so upset about seemingly minor issues. This article provides an example scenario that depicts how a fight between a BPD and a non-BPD person might erupt.
Mary and Jessica have been friends for years, though not without significant turmoil and periods of separation from one another. Mary has BPD. Jessica, usually a rational type who doesn't tolerate abuse from anybody, has repeatedly tried to cut Mary out of her life, only to eventually go against her own advice. While Jessica only has this one relationship that could be described this way, Mary has many; in fact, Mary's life seems to be a constant merry-go-round of relationships. She has more enemies than anyone you know, yet she also has more friends than anyone you know, for the same reasons that Jessica keeps "taking her back": she is incredibly funny, energetic, charming, and uniquely fun. She has a way of making everyone feel comfortable.
Suddenly, the guy in the corner at the bar who you've never seen look anywhere but his shoes for years is suddenly doing the Macarena on the table and giggling like a schoolgirl. Not all borderlines are charmers, but a disproportionate number are. This is why the friend or significant other of a BPD person can frequently be heard saying "I don't usually let people walk all over me" or "I'm not usually this (insert adjective here, such as irresponsible, impulsive, etc.)".
Mary and Jessica's relationship has been on the upswing; Jessica thinks maybe Mary's finally outgrowing her tendency towards impulsive rage episodes and jealous, vindictive behavior. Unfortunately, particularly when things are and have been running smoothly for some time, the trouble begins. The two girls are hanging out with a mutual friend, Katie, who also has had serious strife with Mary over the years. One of Katie's closest friends, Paula, loathes Mary, hearing of the horrendous things Mary has said to Katie over the years. Paula is acquaintance with Jessica, and calls Jessica's phone because she can't get in touch with Katie and figures Jessica might be with her. They chat about nothing for a couple minutes before Jessica hands her phone over to Katie.
Meanwhile, Mary is fuming inside, and the things she is about to do and say will prevent her from being in any of the womens' lives, at least for as long as they can hold out this time. Why? Surely there is more to that boring phone-handing-to-someone story, right? Wrong: while nobody else found anything of note to be happening, Mary felt like Jessica was betraying her by answering the phone for someone that didn't like her. Her mind was racing, wondering if they were ganging up on her on purpose or if Jessica was merely hiding a secret, growing friendship from Mary (she wasn't; in fact, Paula had never called Jessica before). Mary sees herself as the victim of a harsh world. In her mind, though she tries and tries to be a good friend and daughter etc., she just can't win, and she will never get the love that she deserves. Jessica and Katie realize that there's enough love to go around, and don't feel any personal sense of doom if their mutual friends are friends with each other.
Mary doesn't realize that not everyone thinks like her, so she doesn't know how absurd she sounds when she blurts out: "but Paula says awful things about you too, and you shouldn't like her either!" After being forced to account for her behavior, since this comment isn't allowed to slide, a heavily intoxicated Mary cuts her wrists and shows it to Katie and Jessica, sobbing and bemoaning that she has no real friends.
Unfortunately, this kind of scene is the reason that borderlines have the reputation for being manipulative or even "evil". People without a borderline brain have no idea when someone like Mary's anger is brewing, so an eruption of rage seems incredibly impulsive to them, not to mention unwarranted. Mary isn't evil and she isn't aware of how manipulative she is. She doesn't know how to control her strong emotions and she is unaware of how distorted her thinking patterns are. All she knows is that she feels an increasing sense of desperation and impending doom, and her anger and jealousy prevent her from seeing her part in the ensuing drama.
This explanation is not to serve as a justification for inappropriate borderline behavior; like an alcoholic, people with BPD are responsible for treating their illness. However, I do intend to illustrate how borderlines behave to protect themselves from injustice they believe is being done to them. Their behavior is self-protective and defensive and not offensive, despite how irrational these beliefs and behaviors may appear to the rest of the world.
*Borderline personality disorder is diagnosed more frequently in women than men, though some believe it may be due to gender stereotyping rather than a natural prevalence in women over men.