Personality refers to peoples’ thoughts and views on how they relate to their world, and how they relate to others. All people have personality traits that make them unique, such as “shy” or “outgoing” or “humble” or “self-assured.” A personality disorder, however, is deeper and more severe and can cause problems in how a person thinks and feels, which can impact their perceptions and interactions with others. People with personality disorders may not realize that they are thinking or acting in unhealthy ways and tend to be unwilling to change. (Read more about personality disorders.)

Borderline personality disorder is one of 10 personality disorders identified in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR). People with borderline personality disorder have a pattern of unstable relationships, intense fears of being abandoned, impulsive behavior, and extreme emotions, such as intense bouts of anger or anxiety. Although estimates vary, the lifetime prevalence of borderline personality in the United States is approximately 1.4%–2.7% of the adult population (Keepers 2024). Borderline personality disorder is diagnosed when a pattern of extreme changes in self-image, impulsive actions, and troubled relationships emerges. These changes include at least five of the following:

• A pattern of unstable and intense relationships (may switch between extremes of loving someone one moment and then hating that person the next).
• Frantic efforts to prevent someone from leaving them.
• A self-image marked by extreme and frequent changes (may switch between great self-confidence and very poor self-esteem).
• Risky behavior prone to impulse and self-damage, such as spending sprees, risky sex, substance abuse, reckless driving, and binge eating.
• A pattern of suicidal behavior or self-injury.
• Intense bouts of sadness or anxiousness that last a few hours and rarely a few days.
• Often feeling empty (such as feeling bored, sense of having no meaning or purpose).
• Intense anger beyond the scope of the issue, or problems with anger control (such as frequent physical fights or displays of temper, constant anger).
• Fleeting, stress-induced paranoid thoughts or feelings (may suspect others have bad motives or plans against them) or feeling “unreal” or detached from self or the world.

Extreme emotions and impulsive behaviors are not easy for people with borderline personality disorder to prevent or control. Relationships with family and friends may be strained and stressful because of their extreme moods. People with borderline personality disorder may profess intense love or esteem for someone that can quickly turn to intense anger or hate.

The symptoms of borderline personality disorder typically start in adolescence or early adulthood and can persist for many years. Treatment of borderline personality disorder can be effective, and most people will experience reduced symptoms with treatment. Nevertheless, some specific symptoms may persist, and some individuals may need ongoing treatment (Keepers 2024). Several structured psychotherapies are effective for treating borderline personality disorder, though no particular psychotherapy was better than another. Medications do not treat the core symptoms of borderline personality disorder. However, adjunctive medication may be used to address specific target symptoms.

In November 2024, the American Psychiatric Association published updated guidelines on the treatment of people with borderline personality disorder. Among the recommendations are that a patient with borderline personality disorder have a documented, comprehensive, and person-centered treatment plan and be engaged in a collaborative discussion about their diagnosis and treatment.

More information:  Press release on updated guideline and full guideline and related materials.