A mental health professional experienced in diagnosing and treating mental disorders—such as a psychiatrist, psychologist, clinical social worker, or psychiatric nurse, can detect BPD based on:

* An in-person interview to discuss symptoms

* Input from a family or close friend that adds to the information provided by the individual coming for treatment.

In addition, a careful and thorough medical exam can help rule out other possible causes of symptoms.

Diagnostic Criteria

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

1. Fear of abandonment

2. Unstable or changing relationships

3. Unstable self-image; struggles with identity or sense of self

4. Impulsive or self-damaging behaviors (e.g., excessive spending, unsafe sex, substance abuse, reckless driving, binge eating).

5. Suicidal behavior or self-injury

6. Varied or random mood swings

7. Constant feelings of worthlessness or sadness

8. Problems with anger, including frequent loss of temper or physical fights

9. Stress-related paranoia or loss of contact with reality

*Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association

Co-Occurring Disorders

Borderline personality disorder often occurs with other illnesses. This is called co-morbidity or having co-occurring disorders. This can make it hard to diagnose, especially if symptoms of other illnesses overlap with the BPD symptoms.

According to the NIMH-funded National Comorbidity Survey Replication—the largest national study to date of mental disorders in U.S. adults—about 85 percent of people with BPD also suffer from another mental illness.5 Over half the BPD population suffers from Major Depressive Disorder. When depression and BPD co-occur, the depression often does not lift (even with medication), until the borderline personality disorder symptoms improve.

Women with BPD are more likely to have co-occurring disorders such as major depression, anxiety disorders, substance abuse or eating disorders. In men, BPD is more likely to accompany disorders such as substance abuse or antisocial personality disorder.

Most co-morbidities are listed below, followed by the estimated percent of people with BPD who have them:

* Major Depressive Disorder – 60%

* Dysthymia (a chronic type of depression) – 70%

* Substance abuse – 35%

* Eating disorders (such as anorexia, bulimia, binge eating) – 25%

* Bipolar disorder – 15%

* Antisocial Personality Disorder – 25%

* Narcissistic Personality Disorder – 25%

* Self-Injury – 55%-85%