How is borderline personality disorder diagnosed?
If a patient has symptoms, the doctor will perform a complete medical history and physical examination. Although there are no laboratory tests to specifically diagnose personality disorders, the doctor might use various tests—such as X-rays and blood tests—to rule out physical illness as the cause of the symptoms.
If the doctor finds no physical reason for the symptoms, he or she may refer the person to a psychiatrist or psychologist, healthcare professionals who are specially trained to diagnose and treat mental illnesses. Psychiatrists and psychologists use specially designed interview and assessment tools to evaluate a person for a personality disorder.
Because the symptoms of BPD include erratic behavior and profound mood swings, it is difficult to tell it apart from bipolar disorder (formerly manic-depressive disorder). A qualified healthcare professional will determine if the symptoms point to BPD, bipolar depression, or both.