Borderline personality disorder: symptoms, diagnosis and management

Borderline personality disorder (BPD), also known as emotionally unstable personality disorder (EUPD), is a mental health condition that severely affects a person’s ability to regulate their emotions^​1​. It can have a significant impact on their relationships with others. People with BPD/EUPD can experience unstable relationships, a fear of abandonment, impulsive behaviour and extreme emotions, including periods of intense anger or anxiety. BPD is one of ten personality disorders identified in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5)^​2​. The International Classification of Diseases, 11^th revision (ICD-11), no longer distinguishes between the types of personality disorder; however the ICD-11 defines personality disorder as a single condition, which is described in terms of severity (i.e. mild, moderate or severe). At present, the terms BPD and EUPD are still widely used in practice and guidance. The National Institute for Health and Care Excellence (NICE) is investigating whether their existing recommendations can be contextualised in line with ICD-11^​3​.

The prevalence of BPD is estimated to be between 0.7 and 2.0% in the general population, rising to 20% of inpatients in psychiatric wards and 10–30% of outpatients^​4​. BPD typically begins in adolescence or early adulthood. In the UK, 1–5% of adolescents could meet the diagnostic criteria for BPD^​5​.

The life expectancy of people within secondary mental health care with a primary diagnosis of personality disorder was found to be reduced by 17–19 years compared with the general population of England and Wales^​6​. For people aged between 15 and 44 years, the risk of mortality is ten times that of the general population^​6​. This is mainly because of barriers to care for people with BPD with physical health problems, including inconsistent engagement with medical care by some individuals and stigma from clinicians^​7​.

People report experiencing discrimination and stigma as a direct result of receiving a BPD diagnosis^​8,9​, and the care they experience for both physical and mental health is affected owing to their diagnosis^​10​. For example, patients may be told that physical symptoms are “all in your head”^​11​.

There are differing opinions among healthcare professionals, patients and carers about whether a diagnostic label of personality disorder should be used at all. One school of thought is that a diagnosis of BPD constitutes a judgement of an individual’s entire personality, which places blame on the person for their behaviour without acknowledging the impact of trauma and life experiences.¹⁰ Others believe that, although stigma exists, having a recognised diagnosis can be beneficial, as it can help the individual to access support, have meaningful engagement with health services and receive effective treatment^​5,9,11​.

Pharmacists have an important role in the care of individuals with a diagnosis of BPD. Although there are no medications licensed to treat BPD, many patients with a BPD diagnosis are prescribed psychotropic medication off-label^​12​ to treat symptoms of BPD or comorbid mental health conditions, such as depression, anxiety and post-traumatic stress disorder (PTSD).

Understanding BPD is beneficial for pharmacists to help reduce stigma and give advice on medication use in this patient group, leading to better, more person-centred care.

Symptoms

There are a wide range of symptoms associated with BPD. Affected individuals can experience different levels of emotional and behavioural issues. Some can maintain relationships and may be in work, while others can experience severe emotional distress and go through frequent crises, including self-harm and impulsive aggression, which require emergency psychiatric or medical help.³ The symptoms are often grouped into four broad categories^​13​:

• Emotional instability: People with BPD often experience intense emotions that can quickly change. These emotions can be unpredictable and difficult to control, which can affect relationships with others;
• Disturbed patterns of thinking or perception: People with BPD often have distressing thoughts (i.e. that they are a terrible person or feel like they don’t exist). They can experience brief psychotic-like episodes (i.e. hearing external voices, having distressing beliefs or paranoia) or stress‐induced dissociative experiences (i.e. feeling detached from the world around them)^​12​;
• Impulsive behaviour: People with BPD may act impulsively in ways that are harmful and difficult for them to control. They may experience an impulse to self-harm, particularly when feeling low. They may also feel urges to partake in reckless behaviour, which could manifest as substance misuse, unsafe sexual activities or spending sprees;
• Intense but unstable relationships: People with BPD can find it difficult to maintain stable relationships. This difficulty can come from a fear of abandonment and not wanting to be alone (i.e. they may feel very worried about being abandoned and constantly text or call or make threats to harm or kill themselves if the person leaves). It can also be the opposite: they may feel smothered or controlled and respond by emotionally withdrawing or verbally abusing the person in an attempt to get them to leave^​13​.

Symptoms of BPD usually start in adolescence and tend to improve with age^​14​. In older patients, there also appears to be a shift in BPD symptoms, with a reduction in impulsivity and identity issues and an increase in depression, feelings of emptiness and physical complaints. Some symptoms, including emotional instability, unstable relationships, anger and fear of abandonment, are common in all age groups. Risk of self-harm can also remain throughout the life course but may present in different ways — for example, not following medical advice or misusing medication^​15​.

Aetiology

Personality development is dependent on both genetic and environmental factors, as well as the interaction between the two^​16​. Personality traits are how people demonstrate how they think, feel, behave and relate. Personality disorders can be described as the manifestation of extreme personality traits that affect daily living^​14​. However, it is unclear how normal personality traits link to personality disorders.  

There is evidence to show that exposure to adverse childhood events, especially abuse and neglect, is a risk factor for the development of personality disorders^​14,17​. One study, published in 2017, showed that cumulative exposure to childhood adversity is associated with a diagnosis of personality disorder in young adulthood. It also found that the risk of developing a personality disorder increased incrementally as the number of adverse childhood events increased^​18​. However, it is not determinative. Some people’s natural temperament helps them develop normally despite early adversity^​19​, while not everyone with a diagnosis of BPD has a history of trauma^​10​.

Neuroimaging studies have shown that there are differences in neural circuits related to symptoms of specific personality disorders; however, the results of studies are not yet used in clinical practice^​14​. Differences in function in neurotransmitter systems, including the serotonin, glutamate and gamma-aminobutyric acid systems, have been observed in patients with BPD^​20​.

Diagnosis and assessment

People do not tend to present in primary care looking for treatment for BPD; however, they frequently attend for other health issues. BPD is linked to an increased risk of many health problems, including chronic pain, obesity, cardiovascular disease, gastrointestinal disease and sexually transmitted diseases^​7​. Comorbidity with other mental health conditions, such as depression, anxiety, eating disorders, PTSD, alcohol and drug misuse, and bipolar disorder, is common in BPD^​3​.

NICE recommends that healthcare professionals consider referral to community mental health services for assessment if an individual repeatedly self-harms, has evident emotional instability or continually partakes in risky behaviour^​3​.

Personality disorders are diagnosed within mental health teams, using the criteria in the ICD-11 (see Box 1) or DSM-5. Their complexity means they can take time to assess and diagnose. Accurately diagnosing and formulating a treatment plan helps maximise the chance of recovery^​21​.

Management

BPD is associated with impaired quality of life and functioning in a variety of areas, such as vocational, social, emotional and physical health issues^​22​. Symptoms can fluctuate over time and in intensity. Recovery in mental health is more than the remission of symptoms — it is about having a good quality of life. Although some BPD symptoms can improve relatively quickly with psychotherapy, it can take many years for people with BPD to improve their functioning in occupational activities and relationships^​23​.

In clinical practice, the performance of activities of daily living is important for judging symptomatic remission and functional recovery^​24​. The Global Assessment of Functioning Scale can be used to aid understanding of how well an individual can manage daily activities. Some people with BPD will be able to attain a good overall recovery but, unfortunately, there are others for whom this won’t happen^​23​.

Psychosocial interventions

Psychosocial interventions are generally recommended as a first-line treatment for BPD^​15​. A critical review of the literature, published in 2024, concluded that while several psychotherapies were found to be effective in treating BPD, there was no clear ‘gold standard’^​25​. Psychotherapy can be effective in reducing the severity of BPD symptoms, including depression, self‐harm and suicide‐related outcomes, as well as improving psychosocial functioning. There is the most evidence for dialectical behavioural therapy (DBT) and mentalisation-based treatment (MBT)^​16​ in the treatment of BPD. DBT has been shown to reduce anger, self‐harm and improve psychosocial functioning, while MBT appears more effective at reducing self‐harm and suicidality^​26​.

Pharmacological management

There is currently no medication licensed for the treatment of BPD. The evidence for pharmacological management in BPD is weak. NICE recommends that medication should not be used specifically for BPD or the associated symptoms and behaviours^​3​.

Pharmacological treatment is only indicated if there is a comorbid condition that requires medication. NICE also recommends that medication should only be used in conjunction with psychosocial interventions or in acute crises when psychosocial interventions are not available or sufficiently effective^​16​. However, there is a clear difference between published guidelines and what occurs in clinical practice. Medications are widely prescribed in BPD — often for prolonged periods of time^​12​. 

One study, published in 2015, found that prescribing patterns were similar for those with only an EUPD diagnosis and those with EUPD plus another mental health diagnosis. Nearly all the patients with only EUPD received psychotropic medications — mostly to help with symptoms and behaviours associated with EUPD²⁷. The study also found that those patients were less likely to have had their medication reviewed over the previous year than patients with EUPD plus a comorbid condition^​27​. This is despite the NICE recommendation of regular monitoring when using medicines for unlicensed indications^​28,29​.

Sometimes, temporary pharmacological treatment may be appropriate if used alongside psychotherapy^​25​. It may help reduce some symptoms, such as impulsivity, mood swings or psychotic symptoms, in some patients^​25​. This symptom relief may help patients to remain engaged in treatment or decrease short-term risks of harm^​25​.

The choice of medication will depend on the comorbidity or target BPD symptom. A recent systematic review, published in February 2025, hypothesised that guidelines for other mental health conditions with similar symptoms are being used to treat specific BPD symptoms^​30​. The review points out that treating symptoms this way assumes that a particular symptom always has the same cause, which isn’t necessarily true. For instance, low mood in BPD patients doesn’t necessarily mean they have depression and so should not be treated as if they have it ^​30​. Selective serotonin-reuptake inhibitors (SSRIs) may be appropriate for patients with comorbid obsessive compulsive disorder or depression; however, there is insufficient evidence for SSRI use in the treatment of BPD without a comorbidity^​16,25​.

Low doses of second-generation antipsychotics have been used in people with BPD to treat symptoms including psychosis, impulsivity^​31​ and agitation^​16​. Olanzapine, aripiprazole and quetiapine are often used in clinical practice, while mood stabilisers are also commonly used^​32​.

For the management of agitation or sleep during a crisis, sedative antihistamines or low-potency antipsychotics are preferable to hypnotics^​16,33​. If medication is deemed necessary in an acute crisis, it should be prescribed short-term^​3​. For a summary of the NICE guidance on short-term drug treatment for people with BPD, see Box 2.

Substance use disorders frequently co-exist with BPD^​34​. As a result, any concurrent alcohol or illicit drug use should be considered when planning potential treatment^​16​.

Suicidal behaviour

Suicidal behaviour is a significant clinical concern in individuals with BPD — up to 10% of patients with BPD die by suicide^​14,35​. A study, published in 2023, suggested that medication for attention deficit hyperactivity disorder (ADHD), particularly stimulants, should be the preferred choice for patients with BPD presenting with ADHD symptoms and suicidal behaviour^​36​. In addition, impulsivity and emotion dysregulation can be symptoms of both ADHD and BPD.

The study also revealed that there was an almost 48% reduction in the probability of suicide completion in patients with BPD who are taking ADHD medication. It was also observed that patients had a reduced risk of attempted or completed suicide when taking ADHD medication compared with times that they were not taking it^​36​. (Note: it is likely that the patients with BPD who received ADHD medication treatment had comorbid ADHD symptoms.)

The study identified that treatment with benzodiazepines was consistently associated with an increased risk of attempted and completed suicide^​36​. None of the other commonly used classes of medication in BPD (e.g. antidepressants, antipsychotics and mood stabilisers) reduced the risk of suicidal behaviour^​36​.

Medications that are unsafe if taken in overdose^​16​ (e.g. tricyclic antidepressants and propranolol) and those with a high potential for addiction (e.g. benzodiazepines) should be avoided.

For more information on how to respond to recognise suicide risk factors and respond to suicidal ideation, see: ‘Suicide: how to recognise the warning signs and deal with disclosure‘.

Medication reviews

Pharmacists should have an honest discussion about the implications and expectations of medication, including adverse effects and any off-licence use so that patients are fully informed and can make a collaborative decision^​9​.

Relying too much on medication can lead people to think that pharmacological therapy can ‘fix’ feelings^​25​. The symptoms being treated should be defined and a timeframe set for review^​16,25​. Reviews should also include the effectiveness and side effects of medication. Treatment that is not effective should not be continued. 

For those who do not have a diagnosed comorbid mental or physical illness and who are prescribed drugs, the medication review should aim to reduce and stop unnecessary drug treatment^​3​. NICE recommends that such changes are discussed in advance with the person — and their family or carers, if appropriate — and that a clear plan is in place, as withdrawal and ending of treatments can arouse strong emotions and reactions in people with BPD^​3​.

Frequent changes of dose or medication in response to crises or transient mood states are also problematic and rarely effective^​25​. Current and previous medication should be reviewed before initiating a new medication^​25​ to minimise polypharmacy risk.