What the Evidence Really Says About Living with BPD

Borderline Personality Disorder (BPD) has now been studied more than any other personality disorder. Since it was formally recognised in 1980, researchers have explored nearly every aspect of the condition, from diagnosis and comorbidity to neurobiology and psychotherapy. But despite the mountain of evidence, the real-world experience for carers hasn’t changed much. Families still face years of uncertainty, isolation, and exhaustion, often with little to no professional guidance. So what has all this research revealed? And what can carers realistically expect from the current state of treatment?

A Clearer Diagnosis, but Still a Moving Target

One of the biggest accomplishments in BPD research is that the diagnosis can now be made reliably through semi-structured interviews. This is a major achievement given the complexity of symptoms: unstable relationships, impulsivity, emotional turmoil, self-harm, chronic emptiness, and an intense fear of abandonment. And yet, the picture remains murky. The criteria can be met in 256 different ways, meaning two people with the same diagnosis can have almost no symptoms in common.

Efforts to improve diagnostic clarity have led to newer models, such as the dimensional approach in DSM-5 and ICD-11, which try to assess personality functioning more broadly. But even these models leave important aspects out, such as the tendency for regression in unstructured settings, a trait that often leads to crisis but isn’t captured in formal criteria. For carers, this means the label “BPD” may describe someone very well, or barely at all, depending on the individual.

Co-Occurring Disorders Are the Norm, Not the Exception

Perhaps one of the most sobering findings is how rarely BPD exists in isolation. Around 83% of people with BPD also experience mood disorders, 85% have anxiety disorders, and 78% report substance use. More than half meet the criteria for another personality disorder. The overlap with ADHD, PTSD, eating disorders, and bipolar disorder is significant.

These co-occurrences complicate diagnosis, blur treatment priorities, and often leave families juggling multiple care plans (if any exist at all). It also raises the risk of medication overuse, as professionals may prescribe drugs to treat symptoms without addressing the core of the disorder. The research confirms what many carers already know from experience: BPD is rarely a “pure” condition, as it’s a tangled web of emotional, cognitive, and behavioural difficulties that affect every part of life.

Psychotherapy Works. But Not for Everyone

One of the strongest findings from the last two decades is that psychotherapy, not medication, is the most effective treatment for BPD. Randomised controlled trials (RCTs) have consistently shown that several forms of therapy outperform treatment as usual (TAU). These include Dialectical Behaviour Therapy (DBT), Mentalization-Based Therapy (MBT), Transference-Focused Psychotherapy (TFP), and Schema Therapy (ST).

When compared to TAU, these therapies show medium to large improvements in symptom severity (effect sizes around 0.50–0.65). That’s a clinically significant difference. But the story doesn’t end there. Nearly half of people who try these therapies don’t respond well enough. And some studies suggest that dropout rates remain high, with many participants leaving treatment before any benefits can take hold.

Interestingly, no one therapy has consistently outperformed the others. While Schema Therapy showed slightly better results in one network meta-analysis, the number of studies was too small to draw firm conclusions. In real-world conditions, especially where services are overstretched, the question isn’t which therapy is best, but whether any therapy is available at all.

Medications: Limited Role, High Risk

Despite being prescribed in nearly every case, medications have shown no consistent benefit for the core symptoms of BPD. That’s not just a vague warning but a clear finding backed by multiple studies and reinforced by national guidelines, including those from the UK’s National Institute for Health and Care Excellence (NICE). Medications may help with specific issues like severe anxiety or depressive episodes, but they should be used only for short periods and under strict supervision.

Nevertheless, polypharmacy is common. One study found that nearly 19% of people with BPD were on four or more psychotropic medications. The risks here are not just about side effects or dependency but also about masking symptoms that would otherwise be addressed in therapy. For carers, it’s crucial to know that a pill may ease a crisis temporarily, but it won’t provide a long-term solution.

Outcomes Are Improving — Slowly

Here’s some good news: BPD is more treatable than previously thought. Long-term follow-up studies show that many individuals improve significantly. In one 10-year study, half of participants achieved full recovery, and most showed at least partial remission of symptoms. Recovery here meant not just fewer symptoms but also better social and vocational functioning.

But improvements aren’t always stable. About a third of those who achieved remission later lost it, often due to life stressors or untreated co-occurring issues. And even when core symptoms improve, challenges in relationships and self-image often persist.

That’s why researchers now focus more on long-term functioning, not just short-term symptom relief. And it’s why carers continue to play a critical role: stabilising environments, encouraging treatment, and helping maintain gains made in therapy.

Social Cognition and Emotional Understanding Are Key

Newer research has begun to explore what’s actually happening inside the minds of those with BPD not just biologically, but socially and emotionally. The findings? People with BPD often struggle to recognise others’ emotions accurately. They’re more likely to perceive rejection, even when none is intended. And their ability to “mentalize” (to understand the thoughts and feelings of others) can disappear under stress.

These deficits in social cognition may explain why relationships are so difficult to maintain. They may also help us understand the intense fear of abandonment and the sudden mood swings that seem to come out of nowhere.

But there’s a silver lining: therapies like MBT specifically target these issues, and emerging data suggests they can help rebuild these skills over time. For carers, knowing that social misunderstandings aren’t personal but part of the disorder can make a big difference in how they respond during tense or emotional situations.

Neurobiology Offers Clues but Not Certainty

The quest to find a “biological fingerprint” for BPD has been less conclusive. Studies have identified changes in brain areas like the amygdala and prefrontal cortex, particularly during emotional processing. But these findings are often inconsistent and overlap with other disorders. There’s also evidence of altered stress responses and lower cortisol levels, suggesting long-term effects of early trauma.

Still, there’s no unified theory of how BPD works in the brain — and no biomarker that can be used for diagnosis or treatment planning. In practical terms, this means families should be wary of any approach that claims to “fix” BPD through supplements, brain scans, or medication alone.

What Carers Should Know — and Do

Amid all this complexity, carers remain the most under-utilised resource in the system. Yet the evidence is clear: involving families leads to better outcomes. Psychoeducational programmes for carers can reduce stress, improve communication, and help prevent relapse. But such programmes are rare, and access is uneven.

What’s needed is not just more research but systems that translate that research into practical, accessible support for the people already doing the hardest work.

That’s where organisations like BPD UK come in. By offering peer-led education, digital tools, and carer-focused resources, we can close the gap between what science knows and what families actually receive.

Until health systems catch up, carers must advocate for themselves. Know the limits of medication. Push for access to evidence-based therapy. Insist on being included in care discussions (with the individual’s consent). And above all, don’t underestimate your role. Research shows that your support can be just as crucial as any formal treatment.

Read more here, Borderline personality disorder: a comprehensive review of diagnosis and clinical presentation, etiology, treatment, and current controversies. by Falk Leichsenring, Peter Fonagy, Nikolas Heim, Otto F. Kernberg, Frank Leweke, Patrick Luyten, Simone Salzer, Carsten Spitzer, Christiane Steinert: https://onlinelibrary.wiley.com/doi/full/10.1002/wps.21156