A mental illness where a person cannot control their own emotions.
This means that you feel like shit for literally no reason, and you lack the ability to stop it.
Naturally, this results in the afflicted individual engaging in whatever behaviors they find necessary to alleviate their pain.
This, in turn, makes them appear crazy to the outside world.
Borderlines are notoriously frustrating to work with. The thing that people seem to forget is that if they are frustrated with us, we are infinitely more frustrated with ourselves.
Treatment is available. The vast majority of borderlines recover with Dialectical Behavior Therapy (DBT).
Commonly comorbid with depression
I was glad to find out that I had Borderline Personality Disorder because I could finally find words to explain the way I felt... until I realized that I had BPD. Oh, fuck.