In summary:
- Recent clinical research led by Nicholas Day MAPS indicates a significant shift away from the historical "therapeutic nihilism" that once characterised the treatment of Borderline Personality Disorder.
- While BPD was previously viewed as a condition that was nearly impossible to manage, contemporary evidence confirms that it can be treated effectively through targeted psychological interventions.
- The article addresses the systemic stigma and clinical dismissal often associated with Group B personality disorders, advocating for a more person-centred and optimistic approach to diagnosis.
- Nicholas Day acknowledges that treating these presentations remains a complex task for many psychologists, highlighting a critical need for better professional support for clinicians.
Winner of the APS Early Career Researcher award, Nicholas Day MAPS, whose research is focused on borderline personality disorder, addresses misconceptions about BPD and suggests evidence-based ways to treat it safely and effectively.
Note: This article is not intended as an exhaustive clinical framework for managing borderline personality disorder. Instead, it provides a focused overview of recent research insights and specific perspectives shared by our interviewee to inform contemporary practice.
Clinical psychologist and University of Wollongong senior lecturer Nicholas Day says it has been immensely gratifying to watch his peers’ attitudes towards certain personality disorders shift over the past decade.
His own research, which in recent years has focused on borderline personality disorder (BPD), has helped affect this change, and won him the Early Career Research Award at the 2025 APS Major Awards.
But Day acknowledges that, for many psychologists, treating BPD and other Group B personality disorders can be a confusing – and, often, confronting – task.
“It is rewarding work but can be challenging, particularly when it comes to presentations that are less well understood. There is perhaps not as much support for clinicians as there should be,” he says.
Here, Day unpacks his recent research on BPD and nominates four takeaways for practising psychologists.
Nicholas Day, Clinical psychologist and University of Wollongong senior lecturer
1. BPD can be treated effectively
When Day trained as a psychologist in the early 2000s, the prevailing view was that BPD was difficult, if not impossible, to treat, he says.
“Due to the limited evidence base at the time, and the lack of training and support to manage the emotional intensity of the work, there was a pervasive therapeutic nihilism towards BPD.”
“As a result, some clinicians were outright dismissive of the diagnosis. Others were willing to apply the BPD diagnosis but unwilling to treat the condition”, he says.
In the late 1990’s Maroondah Hospital opened its statewide spectrum service (offering DBT), after research across the State demonstrated that the leading cause of burnout for therapists was difficulty managing BPD presentations.
Some understanding existed that trauma underlies BPD, but practitioners were poorly trained to respond to associated behaviours, including self-harm and alcohol/drug use, which requires a harm minimisation approach. Significant changes in attitude have resulted from involving those with lived experience in research.
His own research, conducted during his postdoctoral work with Project Air Strategy (Project Air - University of Wollongong – UOW) – a national leader in the research, education and treatment of personality disorders – has helped effect this change and won him the Early Career Research Award at the 2025 APS Major Awards.
“In those instances, a diagnosis of BPD served to reinforce stigma as a ‘diagnosis of exclusion’ from much needed therapy services,” says Day.
However, a growing evidence base has challenged these views.
“What we’ve seen in the past 25 years are several landmark publications that summarise the breadth of established treatments for BPD,” says Day.
“This is well-designed research – randomised control trials and the like – that really shows that people can recover and get better.”
Transference- focused psychotherapy, mentalisation-based therapy, dialectical behaviour therapy and schema therapy have all been demonstrated as effective, he says.
The studies have started to shift attitudes too. In 2018, Day published research that compared clinician attitudes towards BPD over a 15-year period.
“We found that at the start of the study period, the cohort was using stigmatising pejorative language [to describe clients with BPD], whereas 15 years later they were talking about care plans and trying to find ways to treat this admittedly challenging presentation.”
2. Clients with BPD may benefit from groups led by both clinicians and peers
When a client is diagnosed with a personality disorder, the diagnosis needs to be coupled with understanding and support, so the client doesn’t feel isolated and alone, says Day.
For this reason, peer-support groups have long been considered an important component of treatment.
“Other people with lived experience can be a great bulwark against the stigma that people with personality disorders experience,” says Day.
However, despite having clear value theoretically and qualitatively, studies on peer-led treatments have failed to demonstrate their efficacy, he says.
“Clients would feel validated and understood, but researchers weren’t able to quantify those outcomes clinically.”
In 2025, Day published the results of a randomised controlled trial of a group program for BPD led simultaneously by clinicians and peers.
The study found that participants not only felt positive about their experiences in the group but also demonstrated an ongoing reduction in symptoms.
“Participants spoke about the benefit of having a peer leader who was able to share their lived experience and offer a sense of connection, while also having a trained clinician there to offer psychoeducation and skills development.”
“The co-mingling of those two forms of support seems to be particularly effective.”
3. The onset of BPD is shaped by multiple interacting factors
Recent research by Day and his peers found that, while BPD symptoms emerged at 12.1 years of age on average, study participants weren’t diagnosed until they were 30.2 years old.
This suggests that BPD symptoms could have been initially attributed to other causes or potentially disregarded, or that a diagnosis of BPD was withheld due to the stigma surrounding the condition.
Day’s study also found that participants’ explanations for the emergence of their BPD varied from biological to psychological and social factors.
“Some people said: ‘I had early trauma that set the stage’, while others said: ‘I had no trauma, but I was a really sensitive child.’ The responses varied widely.”
Based on such research and their in-clinic experiences, Day and other psychologists believe that the development of BPD is biopsychosocial – but more work needs to be done to understand its causes.
“We know trauma can have an effect, but it can’t be just that, because some people with BPD deny a trauma history. We know there’s a genetic load, but that doesn’t explain everything, either. The answer seems to be that it’s a real biopsychosocial stew.”
4. Supporting clients with BPD requires real effort
People with borderline personality disorder may experience periods of significant distress and elevated risk, which makes it especially important for therapy to be structured and predictable.
For this reason, Day says the psychologist and client should establish a clear and collaborative therapy agreement early on, including the goals of the treatment and how safety concerns will be managed.
“It’s important that there’s a shared understanding from the outset about what will happen if risks escalate, such as contacting emergency services or family members, so it doesn’t come as a surprise. Using care and safety plans in advance can help create a sense of security and predictability.”
Clinicians also need to be mindful of their own emotional responses when working with clients with BPD.
“The clinician needs to be able to manage their own anxiety and be responsive, not reactive, because this presentation can elicit intense countertransference in clinicians, which means they then act hastily.”
Day notes that this kind of reactive responding may be similar to the invalidating responses these clients report experiencing from others in their daily life.
“That’s why it’s so important for the clinician to do something different. They need to be able to metabolise and sit with the client’s behaviour as something that can be fundamentally understood.
"The clinician staying empathic, reflective and regulated in the presence of intense emotion may be a new experience for the client – this is part of what makes the therapy effective.”