All Collections
Mental health and wellbeing
Mental wellness
What is Borderline Personality Disorder?
What is Borderline Personality Disorder?
Borderline personality disorder is a complex condition that is often misunderstood, so let's learn all about it.
Sonder avatar
Written by Sonder
Updated over a week ago

Kate McLisky is a clinical psychologist with a background in mental health research. Kate works clinically with an integrative therapeutic approach to help clients of all ages to manage and reduce symptoms of mental health disorders.

Borderline Personality Disorder (BPD) is possibly the most controversial and “loaded” diagnosis an individual can receive. For many people, however, BPD is the best descriptor of their cluster of symptoms, and can help to direct individuals into effective treatment.

What is it?

The name doesn’t tell you much, right?

“Borderline”, in this context, was a term used to describe the way that the disorder was thought to sit on the “borderline” between psychotic and neurotic conditions. This is no longer the way that the disorder is understood. However, the name has stuck. You will also often hear it called “BPD”.

So…. What is it?

BPD is classified as a “personality disorder”, which means that it relates to the way we see ourselves and function in our roles, particularly in relationships. Personality disorders are often related to disordered thinking styles and dysfunctional behaviour, as well as poor emotion regulation.

The most recent Diagnostic and Statistic Manual (DSM-5) describes it as: “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.”

To be diagnosed, an individual must meet five of the following nine criteria:

  1. Frantic efforts to avoid real or imagined abandonment

  2. A pattern of unstable and intense interpersonal relationships characterised by alternating between extremes of idealisation and devaluation.

  3. Identity disturbance: markedly and persistently unstable self-image or sense of self.

  4. Impulsivity in at least two areas that are potentially self-damaging (e.g., spending, sex, substance abuse, reckless driving, binge eating).

  5. Recurrent suicidal behaviour, gestures, or threats, or self-mutilating behaviour.

  6. Emotional instability due to a marked reactivity of mood (e.g., intense episodic dysphoria, irritability, or anxiety usually lasting a few hours and only rarely more than a few days).

  7. Chronic feelings of emptiness.

  8. Inappropriate, intense anger or difficulty controlling anger (e.g., frequent displays of temper, constant anger, recurrent physical fights).

  9. Transient, stress-related paranoid ideation or severe dissociative symptoms.

Generally, personality disorders are not diagnosed in children or adolescents, because one’s personality, and other faculties such as impulse control and emotion regulation, are not yet fully formed until adulthood. It’s especially important to ensure that BPD is not confused with complex trauma (C-PTSD), which can present very similarly.

Living with BPD

For those living with BPD, life can feel excruciatingly difficult. Relationships can be difficult to maintain, feelings seem huge and unmanageable, mood swings are frequent and severe, behaviour can be risky, dangerous and feel out of your control. For some individuals, they are often dissociated (not present) and experience chronic suicidal ideation.

Living with an individual who has BPD can also be extremely challenging – trying to support a loved one through their own storm of mental suffering can feel lonely and as though you can never quite get it right. If you are living with an individual with BPD, you might also need to seek some professional help.


Personality disorders are often misconceived to be “lifelong” conditions or to be untreatable. More recently, however, it has become clear that treatment can be effective, with some particular treatments showing excellent results. Probably the best-known treatment for BPD is Dialectical Behaviour Therapy (DBT), which focuses on building skills (learning and applying behaviours) in four areas: mindfulness, emotion regulation, distress tolerance and interpersonal effectiveness. Other evidence-based treatments for BPD include Mentalisation Based Treatment (MBT), Schema Therapy, and Transference-Focused Psychotherapy.

Living with BPD can be extremely difficult, but it’s important to know that help is available! The best way to start is to talk to a GP about accessing help from a professional.

If you have any questions or need extra support, we're here to help you anytime in any language. Simply start a chat with us via the home screen of the Sonder app to connect to our team of qualified, caring health professionals.

Article written by: Kate McLisky

Image credit: Kelly Sikkema at Unsplash

All content is created and published for informational purposes only. It is not intended to be a substitute for professional advice. Always seek the guidance of a qualified health professional.

Did this answer your question?