Borderline Personality Disorder

Learning Objectives

  • Describe the characteristics and diagnosis of borderline personality disorder

So far, we have revied the Type B personality disorders related to impulsive, dramatic, emotional, or erratic behavior. Now we’ll take a closer look at borderline personality disorder (BPD).

Table 1. DSM-5 Personality Disorders
Antisocial continuously violates the rights of others; history of antisocial tendencies prior to age 15; often lies, fights, and has problems with the law; impulsive and fails to think ahead; can be deceitful and manipulative in order to gain profit or pleasure; irresponsible and often fails to hold down a job or pay financial debts; lacks feelings for others and remorse over misdeeds B
Histrionic excessively overdramatic, emotional, and theatrical; feels uncomfortable when not the center of others’ attention; behavior is often inappropriately seductive or provocative; speech is highly emotional but often vague and diffuse; emotions are shallow and often shift rapidly; may alienate friends with demands for constant attention B
Narcissistic overinflated and unjustified sense of self-importance and preoccupied with fantasies of success; feels entitled to special treatment from others; shows arrogant attitudes and behaviors; takes advantage of others; lacks empathy B
Borderline unstable in self-image, mood, and behavior; cannot tolerate being alone and experiences chronic feelings of emptiness; unstable and intense relationships with others; behavior is impulsive, unpredictable, and sometimes self-damaging; shows inappropriate and intense anger; makes suicidal gestures B

Borderline Personality Disorder

Borderline personality disorder (BPD) is a mental illness characterized by a long-term pattern of unstable relationships, distorted sense of self, and strong emotional reactions. Those affected often engage in self-harm and other dangerous behavior. They may also struggle with a feeling of emptiness, fear of abandonment, and detachment from reality.

Photograph of a woman's face as she holds a mask in front of half her face.

Figure 1. Those with borderline personality disorder may quickly change their mood or behavior.

The DSM-5 diagnostic criteria for borderline personality disorder is

A. A pervasive pattern of instability of interpersonal relationships, self-image, and affects as well as marked impulsivity beginning by early adulthood and present in a variety of contexts as indicated by five or more of the following:

  1. frantic efforts to avoid real or imagined abandonment (note: do not include suicidal or self-mutilating behavior covered in Criterion 5)
  2. a pattern of unstable and intense interpersonal relationships characterized by alternating between extremes of idealization and devaluation
  3. identity disturbance marked by a persistently unstable self-image or sense of self
  4. impulsivity in at least two areas that are potentially self-damaging, for example, spending, sex, substance abuse, reckless driving, binge eating (note: do not include suicidal or self-mutilating behavior covered in Criterion 5)
  5. affective instability due to a marked reactivity of mood, for example, intense episodic dysphoria, irritability, or anxiety usually lasting a few hours and only rarely more than a few days
  6. chronic feelings of emptiness
  7. inappropriate, intense anger or difficulty controlling anger, for example, frequent displays of temper, constant anger, recurrent physical fights
  8. transient, stress-related paranoid ideation or severe dissociative symptoms

Differential Diagnosis

When considering a diagnosis of borderline personality disorder, the differential diagnosis should always include other personality disorders since overlap is common, especially within Cluster B. Other diagnostic considerations include

  • substance use disorder
  • non-suicidal self-injury disorder (a time-limited phenomenon in many patients)
  • bipolar disorder (five times less prevalent, but comorbidity approaches 15%)
  • autism spectrum disorder (patients with congenital deficits in theory of mind may also show severe mood dysregulation)

Watch IT

This video provides an overview of borderline personality disorder and also explains how it is differentiated from bipolar disorder.

You can view the transcript for “What is Borderline Personality Disorder?” here (opens in new window).


The behavior in BPD typically begins by early adulthood and occurs across a variety of situations. Substance abuse, depression, and eating disorders are commonly associated with BPD. Approximately 10% of people affected with the disorder commit suicide. There is a genetic predisposition for the disorder. Twin studies show over 50% heritability (greater than that for major depression). Twin studies performed in 2000 and 2008 both demonstrated higher concordance of the rate of borderline personality disorder for monozygotic versus dizygotic twins. Environmental factors that have been identified as contributing to the development of borderline personality disorder include primarily childhood maltreatment (physical, sexual, or neglect), found in up to 70% of people with BPD, as well as maternal separation, poor maternal attachment, inappropriate family boundaries, parental substance abuse, and serious parental psychopathology.

Approximately 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 10-year period.


The causes of BPD are unclear but seem to involve genetic, 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.

As is the case with other mental disorders, the causes of BPD are complex and not fully agreed upon. Evidence suggests that BPD and PTSD may be related in some way. Most researchers agree that a history of childhood trauma can be a contributing factor.


Patients with borderline personality disorder have been shown to have high rates of comorbid disorders:

  • mood disorders: 80% to 96%
    A venn-diagram with three overlapping circles.

    Figure 2. BPD can exist simultaneously with other disorders in a patient.

  • anxiety disorders: 88%
  • substance abuse disorders: 64%
  • eating disorders: 53%
  • attention deficit hyperactivity disorder (ADHD): 10–30%
  • bipolar disorder: 15%
  • somatoform disorders: 10%


Treatment of borderline personality disorder relies on psychotherapy. Three evidence-based therapies are effective for patients with borderline personality disorder. First, mentalizing-based therapy (MBT) helps patients manage emotion dysregulation by feeling understood, allowing them to be more curious and make fewer assumptions about the intentions of the people around them. A second therapy, dialectical behavior therapy (DBT) combines mindfulness practices with concrete interpersonal and emotion regulation skills. Third, transference-focused psychotherapy (TFP) focuses on using the patient–therapist relationship to develop the patient’s awareness of problematic interpersonal dynamics. MBT and DBT each incorporate individual and group treatment over 12 to 18 months. For adolescents, family therapy may be an appropriate substitute for group therapy, though not always.

Try It

Key Takeaways: borderline personality disorder

DSM-5 Criteria:

Characterized by hypersensitivity to rejection and resulting instability of interpersonal relationships, self-image, affect, and behavior.


The prevalence of borderline personality disorder in the general population is 1.6% with a lifetime prevalence of 5.9%.


Borderline personality disorder is multifactorial in etiology, including genetic, environmental, and social factors.


Long-term psychotherapy is currently the treatment of choice for BPD.

Case Study: BPD

A 23-year-old woman, Nikki, reacted with depressive symptoms and suicidal thoughts after the death of her grandfather. She was treated with antidepressant medication without addressing the loss. Three years later and after a suicidal attempt, she was admitted to a hospital where she first presented with depressed mood and suicidal thoughts, but quickly engaged in vivid conversations with the other patients. Nikki was discharged with the diagnosis of personality disorder, but soon re-admitted because of suicidal thoughts, and referred to an outpatient program specialized in the treatment of personality disorders.

Since childhood, Nikki has displayed unstable moods, aggressive temperament, and self-destructive behaviors (headbanging). At the age of 10, she was sexually abused by an older man. Suicidal thoughts and urges to kill herself were first experienced at age 11. Since age 13, she has had multiple sexual partners but also a seven-year long relationship, which was quite unstable with frequent conflicts and impulsive acts. Nikki dropped out of school and has been living on disability benefits, interrupted by short periods of employment.

In a two-year psychoanalytic treatment program, with one individual session and one group session each week, Nikki worked together with other patients on identifying and understanding the characteristic features of borderline personality disorder. Her self-destructive behavior tapered off after three months as she began to process her feelings of aggression and sadness. The pharmacological treatment terminated after six months and she quickly became less sedated and anxious. Nikki resumed school towards the end of the first year of treatment, with the intention of taking a degree in teaching. The relationship with her boyfriend stabilized. Contacts with class became more satisfying, and conflicts with her teachers stopped. Her ability to begin to contain feelings increased dramatically.

Try It


borderline personality disorder: characterized by instability in interpersonal relationships, self-image, and mood, as well as impulsivity; key features include intolerance of being alone and fear of abandonment, unstable relationships, unpredictable behavior and moods, and intense and inappropriate anger

personality disorders: a class of mental disorders characterized by enduring maladaptive patterns of behavior, cognition, and inner experience, exhibited across many contexts and deviating from those accepted by the individual’s culture; patterns develop early, are inflexible, and are associated with significant distress or disability