A diagnosis of BPD is based on the signs and severity of the symptoms. It includes a psychological evaluation and the history of the individual and the family. There are no definitive tests for BPD.
To determine the presence of the disorder, the mental health practitioner will conduct an interview. This mental-health interview will look for the presence of symptoms or diagnostic criteria that were previously described. The practitioner will work towards ruling out other mental disorders like depression, anxiety disorders, and other types of personality disorders like narcissistic personality disorder, schizophrenia, bipolar disorder or substance abuse problems. This is common with any type of mental-health assessment.
The professional will also try to ensure that the person is not suffering from any other physical condition which may cause emotional disturbances. To confirm whether a person has BPD he/she must meet the criteria laid out in the Diagnostic and Statistical Manual of Mental Disorders. This manual is used by mental health professionals as an aid to proper diagnosis and by insurance companies for reimbursement of expenses incurred for treatment.
In order to qualify for a diagnosis of BPD, the Diagnostic and Statistical Manual of Mental Disorders state that an individual must have at least five of the following symptoms:
The diagnosis is usually easier to make in adults as similar symptoms in children and adolescents may disappear with maturity.