The term ‘borderline personality’ was introduced in the United States by Adolph Stern in 1938 (most other personality disorders were first described in Europe). He chose the term ‘borderline’ because what he was observing in patients ‘bordered’ on other conditions. The term ‘borderline personality organization’ was introduced by Otto Kernberg in 1975 to refer to a consistent pattern of behaviors characterized by instability. The cluster of symptoms and behavior associated with borderline personality were becoming more widely recognized, and included striking fluctuations from periods of confidence to times of absolute despair, markedly unstable self-image, rapid changes in mood, with fears of abandonment and rejection, and a strong tendency towards suicidal thinking and self-harm. The characteristics that now define borderline personality disorder were described by John Gunderson and Jonathan Kolb in 1978 and have since been incorporated into contemporary psychiatric classifications.