Borderline personality disorder (BPD), also known as emotionally unstable personality disorder (EUPD), is a personality disorder characterized by a long-term pattern of intense and unstable interpersonal relationships, distorted sense of self, and strong emotional reactions. Those affected often engage in self-harm and other dangerous behaviors, often due to their difficulty with returning their emotional level to a healthy or normal baseline. They may also struggle with a feeling of emptiness, fear of abandonment, and detachment from reality.
Symptoms of BPD may be triggered by events considered normal to others. BPD typically begins by early adulthood and occurs across a variety of situations. Substance use disorders, depression, and eating disorders are commonly associated with BPD. Some 8 to 10% of people affected by the disorder may die by suicide. The disorder is often stigmatized in both the media and the psychiatric field and as a result is often underdiagnosed.
The causes of BPD are unclear but seem to involve genetic, neurological, environmental, and social factors. It occurs about five times more often in a person who has an affected close relative. Adverse life events appear to also play a role. The underlying mechanism appears to involve the frontolimbic network of neurons. BPD is classified in the American Diagnostic and Statistical Manual of Mental Disorders (DSM) under the dramatic cluster of personality disorders, along with antisocial, histrionic, and narcissistic personality disorder. The condition, and other personality disorders, can be misdiagnosed as mood disorders, substance use disorders, or other disorders.
BPD is typically treated with psychotherapy, such as cognitive behavioral therapy (CBT) or dialectical behavior therapy (DBT). DBT may reduce the risk of suicide in the disorder. Therapy for BPD can occur one-on-one or in a group. While medications cannot cure BPD, they may be used to help with the associated symptoms. Quetiapine and SSRI antidepressants remain widely prescribed for the condition, though there is no evidence regarding the efficacy of SSRIs. Severe cases of the disorder may require hospital care.
About 1.6% of people have BPD in a given year, with some estimates as high as 6%. Women are diagnosed about three times as often as men. The disorder appears to become less common among older people. Up to half of those with BPD improve over a ten-year period. Those affected typically use a high amount of healthcare resources. There is an ongoing debate about the naming of the disorder, especially the suitability of the word borderline—the term originally referred to patients on the border between neurosis and psychosis, and that interpretation of the disorder is now considered outdated and clinically inaccurate.