What Is Borderline Personality Disorder (BPD)?

Trusted info on borderline personality disorder. Includes definition of borderline personality disorder, BPD criteria, causes, statistics, more.

Borderline personality disorder (BPD) is a severe mental illness in which an individual shows a long-term and consistent pattern of unstable moods and emotions. In other words, the individual cannot properly regulate his or her emotions, resulting in an inner experience that causes impulsive behaviors and chaotic interpersonal relationships (borderline personality disorder relationships).

Mental health professionals officially recognized the condition in 1980. It was named borderline personality disorder because it seemed to occur “on the border” between neurosis and psychosis. Although experts still refer to the disorder by this name, it’s no longer considered to accurately describe the core behaviors.

Exactly What Is Borderline Personality Disorder?

To effectively answer the question -- what is borderline personality disorder -- you'll need to understand the inner emotional experience of the borderline personality. Think of it as emotional dis-regulation. When an air conditioning system is having problems, it may make your home too hot one minute and too cold the next. The temperature regulator within the air conditioning unit clearly has issues if this is happening. BPD is kind of like that when it comes to regulation of emotions.

When you have borderline personality disorder, you have incredibly intense emotions and may show a lack of regard for personal safety. This recklessness regarding personal safety may manifest in the form of self-harm (cutting), promiscuous sex, and suicidal ideation. You will also have issues with identity and self-image and your sense of self may change from one day, or even one moment, to the next.

For instance, sometimes you may view yourself as evil, other times you may feel as if you don't exist. This unstable self-image makes you impulsive and erratic, causing frequent changes in jobs, relationships, personal values, and goals. You can read more about living and dealing with borderline personality disorder here.

Interesting Borderline Personality Disorder Statistics

The National Institute of Mental Health (NIMH) published some interesting borderline personality disorder statistics, stating that 1.6 percent of the adult population has BPD. Some sources claim that the disorder affects 1-6 percent of the U.S. population; with others saying it might be as high as 10 percent. Read over these facts and statistics published by the National Education Alliance of Borderline Personality Disorder (NEABPD):

  • More people have borderline personality disorder than have schizophrenia and bipolar disorder.
  • Up to 5.9 percent of American adults have BPD.
  • Of inpatients in psychiatric hospitals, 20 percent have BPD.
  • Of outpatients receiving treatment in psychiatric hospitals, 10 percent have BPD.
  • Over half of adults with BPD practice self-harm.
  • Ten percent of adults with BPD commit suicide

Among the adult population are many famous people and celebrities with borderline personality disorder.

Borderline Personality Disorder Criteria

The borderline personality criteria are listed in the Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition:

  • Significant impairments in function of personality (i.e. poorly developed sense of self, poor self-direction)
  • Impaired interpersonal function – poor ability to empathize and impaired ability to form lasting intimate relationships
  • Pathological personality traits – frequent, intense mood swings; separation insecurity; frequent, short-lived bouts of anxiety and depression. Impulsivity, hostility toward others, recklessness.
  • These impaired abilities and pathological traits occur consistently over time regardless of circumstance or situation.

Causes of Borderline Personality Disorder

The exact causes of borderline personality disorder are unknown. As with most mental illnesses, experts believe genetic, familial, and social factors all play roles in its development. People with the following risk factors may have a greater chance of developing the disorder:

  • One of both parents have borderline personality disorder
  • Disrupted and dysfunctional family life
  • Poor communication within the family
  • Close family member (father, mother, sibling) with BPD or another personality disorder
  • Sexual, emotional, or physical abuse in childhood or adolescence

Read: Treatment of Borderline Personality Disorder

Borderline Personality Disorder in Men

Although borderline personality disorder in men occurs at about the same rate as it does in women, far more women receive a BPD diagnosis. Researchers don't have a clear picture of why mental health professionals diagnose borderline personality disorder in women more often than in men. Some theorists believe there may be issues with the way it's diagnosed or that more women with the condition end up in treatment.

Borderline Personality Disorder in Children

Some studies suggest that there are indicators of borderline personality disorder in children, reporting that early signs of borderline personality disorder may show up in childhood. Certainly children with one or more of the risk factors may begin to develop the disorder early on, even if it doesn't really show up until adolescence or early adulthood.

The emotional instability, erratic behavior, and pathological traits of a borderline personality may seem as if they could occur in almost anyone – and they can. Everyone behaves erratically, impulsively, and in risky ways at some point in life. The individual with borderline personality disorder behaves in these inappropriate ways consistently and has a pattern of the negative behaviors over the long-term.

article references

APA Reference
Gluck, S. (2021, December 17). What Is Borderline Personality Disorder (BPD)?, HealthyPlace. Retrieved on 2024, July 25 from

Last Updated: January 28, 2022

Medically reviewed by Harry Croft, MD

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