What is Borderline Personality Disorder?

A Look at Borderline Personality Disorder

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Medical Specialties:


Clinical Definition:

Borderline personality disorder, or BPD, is considered a serious mental illness. It's one of a group of conditions under the umbrella term of personality disorders. Those with BPD have often intense, unstable emotions and engage in risky behaviors such as overspending, unsafe sex or abusing drugs and alcohol.

In Our Own Words:

Borderline personality disorder or BPD is a mental illness caused by a combination of biological and psychological factors.

Those diagnosed may be born with a vulnerability to BPD and then later, symptoms may be triggered by stress or other factors such as abuse, inconsistent parenting or childhood trauma.

Those with BPD often have chaotic interpersonal relationships, mood swings and impulsive behavior. To diagnose BPD, doctors take a careful history to rule out other illnesses first; recommended treatments may include psychotherapy (''talk therapy'') and medication.

More Information About Personality Disorders

Personality disorders represent patterns of feeling, thinking and behavior that are ingrained in the individual and difficult to change. These disorders often cause substantial personal distress.

More specifically, personality disorders aren't attributable to other general medical or psychiatric disease nor are they attributable to substance-use disorders. This distinction is critically important because the first sign of many illnesses--like a brain tumor in the frontal lobe--is personality change.

Many clinicians characterize people with personality disorders as difficult to work with because these patients are often demanding and resistant or unable to adhere to treatment plans.

Even though the DSM-5, or the standard classification of psychiatric disorders employed by mental healthcare professionals in the United States, categorizes personality disorders as distinct, many experts view personality disorders as lying on a continuum between normal functioning and psychiatric illness.

For instance, borderline personality disorder can be viewed as existing at "border" between neuroses and psychoses.

Personality disorders are grouped into the following 3 clusters:

  • Cluster A personality disorders apply to people who are odd or eccentric and includes schizoid, paranoid and schizotypal types.
  • Cluster B personality disorders refer to people who are erratic, emotional and impulsive and includes borderline personality, histrionic and narcissistic types.
  • Cluster C personality disorders refer to people who are fearful and anxious and includes dependent, avoidant and obsessive-compulsive personality types. Please note that obsessive-compulsive personality disorder is different from obsessive-compulsive disorder.

Of note, people with one type of personality disorder can have another type of personality disorder, too. Furthermore, people with personality disorders are more likely to have comorbid, or accompanying, psychiatric disorders.

Antidepressant medications sometimes help people with personality disorders.

Additionally, dialectical behavior therapy (DBT), a form of cognitive behavior therapy or psychotherapy, may also help people with personality disorders. Dialectical behavior therapy focuses on behavior change all while encouraging self-compassion, self-acceptance and self-validation.


The Cleveland Clinic. "Borderline Personality Disorder." Diseases & Conditions. Apr. 2010. Accessed Aug. 2013.

Harvard Health Publications. "Treating borderline personality disorder." Harvard Mental Health Newsletter. June 2010. Accessed Aug. 2013.

American Psychological Association. "Help for personality disorders" 2013. Accessed Aug. 2013.

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