Explainer: what is borderline personality disorder?

We all possess a unique set of personality traits that make us who we are. These are the usual ways we perceive, think, feel, behave and relate to others, and they tend to be consistent across time and situations.

Personality traits can become “disordered” when they’re extreme and/or inflexible, making it difficult for the person to adjust to their environment. This causes significant distress and disruption to the lives of those with the disorder. And because it’s difficult to form and maintain relationships, it also affects the lives of those around them.

Borderline personality disorder (BPD) is a severe mental disorder characterised by problems regulating emotions and thoughts, unstable interpersonal relationships and self-image, and impulsive and self-damaging behaviour. The disorder exists along a continuum of severity, with symptoms varying from person to person. These might include:

• emotional volatility
• excessive anger
• “black and white thinking” about relationships (being either all good or all bad)
• a distorted, unstable or unformed sense of self
• intense fears of abandonment
• chronic feelings of emptiness
• recurrent, deliberate self-harm (such as cutting)
• impulsive behaviours with a high likelihood they will cause damage, such as impulsive alcohol use, repeated unsafe sex, binge eating and so on
• feelings of unreality and suspicion when under stress.

BPD was officially recognised by the psychiatric community in 1980 and is currently diagnosed when a patient has at least five of the nine criteria listed in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5). While experts generally agree that “borderline personality disorder” is a misnomer, based on the now disbelieved theory that BPD lies on the “border” between “neurosis” and “psychosis”, they have been unable to reach a consensus on a more accurate term.

The disorder affects 1% to 3% of youth and adults and one-fifth of psychiatric patients, usually beginning in adolescence or early adulthood. This, of course, increases the potential for further developmental disruption into adulthood.

People with BPD also have high rates of psychiatric disorders, such as depression, anxiety, and eating disorders and alcohol and other drug use. Sadly, up to 10% of adults with the disorder commit suicide.

Causes and risk factors

Our understanding of developmental pathways leading to BPD has been improved by recent research studies, but there is still much that is unknown. However, we know that people with a personality disorder don’t choose to feel the way they do.

It’s likely that genetics and environment play a role, with genetically “sensitive” individuals at greater risk of BPD if they find themselves in an enabling environment. A number of childhood and parental demographic characteristics, bad childhood experiences, early relational difficulties, and unhelpful parenting styles are risk factors for BPD.

But these risk factors are common to many psychiatric disorders, making it hard to explain why an individual might develop BPD, rather than another disorder.

Preliminary studies also suggest the brain regions involved in the regulation of emotions and behaviour play an important role in BPD.

Treatment

The treatment of BPD has progressed significantly over the past two decades, with new Australian guidelines outlining interventions for the management of BPD in youth and adults at all levels of the health-care system.

Several structured psychological therapies have been specifically designed for BPD. The best known and most widely practised of these is Dialectical Behaviour Therapy (DBT). This combines individual and group therapy and is directed at teaching skills to regulate intense emotional states and to reduce self-destructive behaviours.

Some features common to all of the effective therapies include having a clear treatment framework, managing emotions during therapy, the therapist being active with the patient, and using exploratory and change-oriented interventions.

When these are conducted by trained and supervised health professionals, they are effective in improving the lives of those with BPD by reducing self-destructive behaviours and improving emotional control, interpersonal relationships and vocational functioning.

Research shows that medications should not be the main treatment for BPD. Medications can be used for co-occurring problems (such as depression) and might have a very limited role as a specialist treatment for some of the symptoms of BPD, and they can lead to long-term complications.

Treatment hurdles

Many people with BPD have experienced significant adversity in their early lives, which is likely to be both a cause and an effect of BPD – and it often continues into adult life. This requires particular sensitivity among health-care professionals.

But BPD has an undeserved reputation among clinicians of being difficult to treat. Complications arise in part because the interpersonal problems at the heart of BPD also affect relationships with professionals. Consequently, patients can encounter prejudice and discrimination within the health-care system and this often compounds their difficulties.

While BPD is a severe psychiatric disorder, it responds well to treatment. The principal challenge is to strengthen the health-care system so that it can provide timely, high-quality, consistent, respectful and collaborative care for people with BPD.

Andrew Chanen receives funding from the National Health and Medical Research Council, the Australian Research Council, New South Wales Department of Health. The Orygen Youth Health Research Centre receives unrestricted philanthropic funding from the Colonial Foundation.