As with most mental disorders, the causes of borderline personality disorder (BPD) are not completely understood.
A combination of factors, including genetic predisposition, developmental or psychological problems, neglect, abuse or trauma during childhood, may make some people more susceptible to developing BPD.
Even if a person has a genetic predisposition for BPD, they won't necessarily develop the disorder.
Environmental triggers, such as a stressful event or relationship breakup may cause BPD to develop in someone who has a genetic predisposition.
A history of trauma, abuse and neglect during childhood is common in people with BPD and can increase the risk of BPD. But not everyone who develops BPD has experienced trauma as a child, nor does everyone who experiences trauma develop BPD.
During times of stress, many people with borderline personality disorder experience post-traumatic stress symptoms, such as flashbacks, nightmares, dissociative states, feelings of unreality and panic attacks.
Sometimes negative experiences from the past return as voices or punishing self-talk that feel real and are difficult to ignore.
Last reviewed: December 2016