In the past, and still quite commonly now, the term "Borderline Personality Disorder" is used. This name originally developed because people thought this problem was "borderline psychotic" because of the voice that sufferers commonly describe. After this the term "Emotionally Unstable Personality Disorder" started to be used more commonly. This better describes the very unstable emotions but says nothing about where the problem comes from. Most recently, researchers have come to understand how these patterns come from abuse, stress or trauma in childhood and how similar the patterns are to people who suffer trauma in adulthood, for example, soldiers in war situations. The pattern of problems they get, which is very similar, is called Post Traumatic Stress Disorder (PTSD). So we now call these problems "Complex PTSD".