Shaolin,
This is kinda OT, but where a lot of Borderlines have addiction issues, I'll answer it.
Borderline Personality Disorder is a serious, serious mental illness. It's what is called a "character disorder", whereas something like Bipolar Disorder is a mood disorder.
It's a complicated answer, but the long and short of it is Borderlines are petrified of abandonment, real or perceived, but they behave in such a way that pushes people away. Kinda like, "I hate you, don't leave me" sort of behavior. Their interpersonal relationships are incredibly unstable and turbulent. They are capable of being incredibly manipulative, especially sexually. They may use suicide threats as a form of manipulation. Cognitive distortions are the norm for them. I can go on, and on, and on.
In popular culture, Glenn Close's character in Fatal Attraction is someone that shows a lot of Borderline traits. Drew Barrymore's character in Mad Love could also be considered a Borderline.
Unfortunately, BPD is an incredibly difficult thing to treat. It's not like a mood disorder, or clinical depression, where you can alleviate the symptoms with a combination of the appropriate medications. Successful treatment of BPD means years and years of either cognitive behavioral therapy or dialectical behavioral therapy.
From what I've read, 50% of psych hospitalizations for BPD also have addiction issues. In the case of my AXGF, she is an opiate addict, and opiate addicts primarily seek to numb themselves so they don't feel what they feel. They want to escape.
Frankly, my AXGF was a nicer person when she was higher than a kite. It was when she stopped using the real her slowly emerged...and it was (and is) U G L Y.
Hope this answers your question somewhat.
ZoSo