At one time, BPD was informally used, a catch-all for a diagnosis that didn't fall into other groups. Five of the eight must be present to meet the criteria for BPD, although, the risk of suicide increases with each inclusion. Frantic efforts to avoid real or imagined abandonment. Unstable and intense interpersonal relationships. One moment they may idealize their partner, the next, completely devaluate them.
Identity is always in question.
Unstable self-image and sense of self. Borderlines have even been know to change their gender in search of self. At least in two areas and are self damaging. Self-mutilating, gestures, threats and behavior. Severe mood shifts.