Borderline Personality Disorder (BPD) is a condition in which an individual has severe difficulty regulating their emotions, leading to anger outbursts, unstable relationship patterns, suicidality, episodes of self-harm, chronic feelings of emptiness, unstable sense of self, and mood swings. People with BPD often have a chronic fear of abandonment and will go to extremes to avoid real or perceived abandonment. BPD is caused by childhood trauma and, in some senses, is like a specialized form of post-traumatic stress disorder (PTSD).