What defines borderline personality disorder?

Individuals with this psychopathology have much difficulty with self-regulation; the regulation of their own emotional state. A lot of people with BPD also have depression and many are suicidal. Often, they have a history of feeling attacked or uncared for. They are almost hypersensitive to perceived threats from others.

They can react almost with a hair trigger if they feel that they are being attacked, and they are likely to respond with counterattack. People with BPD can be so preoccupied by their own sense of not being cared for and not being understood that they become blind to the impact of their own behavior on others.