What is Borderline Personality Disorder?
What is borderline personality disorder (BPD)? Including a list of symptoms for self-diagnosis, and how common is it and what causes it?
What is Borderline Personality Disorder?
Borderline Personality Disorder (BPD) is a mental health condition classified as a personality disorder. It involves long-term patterns of significant emotional instability, difficulties regulating emotions, unstable sense of self-identity, impulsivity, and challenges in interpersonal relationships.
People with BPD often experience intense and rapidly shifting emotions, have a deep fear of abandonment, and struggle to maintain stable views of themselves and others. This can make everyday functioning, relationships, and self-image very challenging. It’s sometimes also referred to as emotionally unstable personality disorder (EUPD) in certain regions.
BPD affects roughly 1-3% of adults. Symptoms often emerge in adolescence or early adulthood. Causes are not fully understood, but likely a mix of genetic factors, brain differences in emotion regulation areas, and environmental influences (especially childhood trauma, invalidating environments, or abuse/neglect).
Symptoms
According to major sources like the DSM-5 (the standard diagnostic manual used by mental health professionals), a diagnosis typically requires at least five of the following criteria, present over time and across situations (beginning in early adulthood). They often make efforts to avoid real or imagined abandonment. This can include extreme behaviours to prevent separation or rejection, even when the threat isn’t realistic.
Unstable and intense relationships
Often alternating between extremes: idealizing someone one moment (seeing them as perfect) and then devaluing them (seeing them as cruel or worthless).
Unstable self-image or identity
A persistently shaky or changing view of who one is, including sudden shifts in goals, values, or identity.
Impulsivity
Examples include reckless spending, substance misuse, binge-eating, dangerous driving, and other risky behaviours.
Recurrent suicidal or self-harming behaviour
This includes cutting, or other forms of self-injury (very common in BPD).
Emotional Instability
Intense mood swings/reactivity, including episodes of severe irritability, anxiety, or depression that last a few hours to a few days. Chronic feelings of emptiness and persistent boredom
Difficulty controlling anger
Frequent temper outbursts, constant anger, or physical fights.
Paranoia or severe dissociative symptoms
Under stress, temporary paranoia (feeling persecuted) or dissociation (feeling detached from reality, numb, or “unreal”). These symptoms often lead to stormy relationships, frequent crises, and high emotional pain. Many people with BPD describe feeling emotions more intensely and for longer than others, with difficulty returning to a calm baseline.
