Prevalence of borderline personality disorder

Borderline personality disorder is the most prevalent personality disorder, affecting an estimated 2% of the general population. It is identified in 10% of individuals seen in out-patient mental health clinics and up to 15–20% of in-patients in psychiatric facilities (Pascual Reference Pascual2010; American Psychiatric Association 2024). The clinical management of individuals diagnosed with borderline personality disorder has been, is and will remain a complex issue at multiple levels unless the persistent and significant gaps in our knowledge regarding evidence-based treatments are filled (American Psychiatric Association 2024), as current evidence (which is of low quality) has not demonstrated clear therapeutic effects (Stoffers-Winterling Reference Stoffers-Winterling2022).

The rise in pharmacotherapy

The use of pharmacotherapy, often involving multiple psychotropic medications prescribed indiscriminately for this clinical population, has become increasingly concerning (Pascual Reference Pascual2010). This is despite precise recommendations regarding pharmacotherapy, such as: initially employing psychosocial strategies; prescribing pharmacological treatment only for specific symptoms and for brief periods; ensuring that pharmacological treatment is always accompanied by psychotherapy; and, for patients without significant comorbidities, aiming to reduce and potentially discontinue pharmacotherapy (National Collaborating Centre for Mental Health 2009; Tennant Reference Tennant2023; American Psychiatric Association 2024). Nevertheless, the prevalence of psychotropic medication use in borderline personality disorder is striking, with reports indicating usage rates from 70% (Bridler Reference Bridler2015) to as high as 94% (Pascual Reference Pascual2010).

Despite the American Psychiatric Association’s (2024) recommendation to reassess the patient’s need for pharmacological treatment of borderline personality disorder every 6 months, long-term polypharmacy is common. Studies have reported polypharmacy involving three or more psychotropic medications in 49.9% (Tennant Reference Tennant2023) and 56% of patients (Pascual Reference Pascual2010), and involving four or more in 30% (Pascual Reference Pascual2010) and seven or more in 8.4% (Tennant Reference Tennant2023). The most prescribed treatments are antidepressants, antipsychotics, benzodiazepines and mood stabilisers (Stoffers-Winterling Reference Stoffers-Winterling2022).

Psychotropic prescriptions for individuals with borderline personality disorder have risen significantly, even when comparing among types of medication groups, age groups, and even other mental health conditions and comorbidities, both psychiatric and non-psychiatric (Bridler Reference Bridler2015). There is evidence that, although the prescription of psychotropics for other mental disorders has been diminishing, borderline personality disorder is one of the few diagnoses that, over the past decade or so, has seen an increase in psychotropic prescribing, against evidence-based clinical and therapeutic recommendations (Bridler Reference Bridler2015; Tennant Reference Tennant2023).

Although psychotropic medication use should be considered a viable option in various contexts – especially for people with comorbid mental health conditions such as major depressive disorder, severe substance use disorders or anorexia nervosa (Pascual Reference Pascual, Arias and Soler2023) – studies of clinical samples have reported high rates of psychotropic use in individuals with borderline personality disorder without known comorbidities. Among the most prescribed medications are second-generation antipsychotics (82.4%), selective serotonin reuptake inhibitors (64.7%), mood stabilisers (41.2%) and tricyclic antidepressants (35.2%) (Riffer Reference Riffer2019).

The need for these therapeutic strategies in severe cases has been widely emphasised, but always as a complementary approach to psychotherapeutic or psychosocial processes (National Collaborating Centre for Mental Health 2009; Pascual Reference Pascual, Arias and Soler2023; Tennant Reference Tennant2023; American Psychiatric Association 2024). However, the limited and methodologically flawed evidence (Stoffers-Winterling Reference Stoffers-Winterling2022) raises questions about whether the high rates of polypharmacy are truly evidence-based.

Overmedication and the knowledge void

This prompts a critical question: Why overmedicate individuals with borderline personality disorder?

It is crucial to genuinely question the appropriateness of pharmacological management when assessing a person with a diagnosis of borderline personality disorder. It is well-known that clinical improvement in this group is often less pronounced than in other diagnoses, which may, at times, manifest as significant clinical frustration among patients themselves, their families and, of course, mental health practitioners. Could it be that, at least in some cases, overmedication reflects the clinician’s clinical/therapeutic frustration, rather than the true need for pharmacotherapy?

A naturalistic study involving people with borderline personality disorder reported that 6 months of weekly dialectical behaviour therapy led to reduction in the number of medications prescribed (mainly in benzodiazepines, mood stabilisers and antipsychotics), implying that providing skills for addressing emotion dysregulation, increasing distress tolerance and improving interpersonal relationships are useful and could encourage patients with this diagnosis to reduce the number of medications taken (Soler Reference Soler2022).

These unanswered questions might shed some light on the void of knowledge regarding the overmedication problem itself. More and better studies (as most researchers note) should be performed to begin a meta-search for answers. In the meantime, we hope that this commentary contributes to the discourse on appropriate current practice.