BPD is most commonly caused by childhood trauma. It does not usually seem apparent until early adulthood. One can detect BPD by having extreme struggles with relationships and trust. If you have an excessive amount of concern in thinking people have ulterior motives for wanting to have a relationship with you, this is also a sign. Self harm and feelings of insecurity are other common symptoms.
Borderline Personality Disorder is medically diagnosed and is very common. "More