Borderline personality disorder (BPD) is estimated to impact about 14 million Americans, or 2% of the U.S. population. The disorder can be marked by unstable mood swings and instability with behaviors and relationships. These symptoms bring significant challenges to an individual regarding their self-image and self-worth, leaving them with intense self-doubt and fears of abandonment.
Until decades ago, the prevailing thought was that because a person can’t change their personality, a disorder like BPD could not be treated. Thanks to research from Mary C. Zanarini, EdD, director of the Laboratory for the Study of Adult Development at McLean Hospital, that misconception has been flipped on its head.
Zanarini was the principal investigator of the McLean Study of Adult Development, a study that began in 1992 and has followed more than 300 individuals diagnosed with BPD for decades. This prolific research has changed the way the medical and mental health patient community views BPD and continues to generate new findings. In the past year alone, Zanarini and her colleagues have published more than a dozen new studies.
Thanks to contributions from Zanarini and team, it is now known that BPD is the most treatable major mental health condition, and patients who receive proper treatment, namely psychotherapy, can go on to live healthy, productive lives. The team’s work has also helped to reduce stigma about BPD, eliminate barriers to diagnosis, and show how much progress can be made when researchers and participants work closely together to better understand mental health.
With the study recently ending, Zanarini looked back on how the research originated, examined some of the key findings that have come out of this first-of-its-kind study, and reflected on what people diagnosed with BPD and their families should take away from this groundbreaking research.
Why did you decide to pursue a long-running study of BPD?
Prior to starting graduate school at Harvard, I worked at McLean Hospital as a mental health worker, where I was assigned to a unit that treated patients with what we now know as BPD. I remember being really surprised by how responsive they were when helping them think of more adaptive responses to situations they perceived as hopeless. And I thought at the time, ‘These people are really treatable.’
Then, when I got to graduate school, my mentor, Dr. George Vaillant, who was a famous longitudinal researcher [who studied adult development], encouraged me to stay in research. With my personal experience working with patients with BPD, a longitudinal study felt like the logical thing to do.
How did you go about conducting this study?
Before we started tracking people with BPD, we had to develop the instruments and measures required to follow them long-term. We developed structured interview questionnaires and self-reported surveys that we would administer every two years.
Most of the people who stayed in the study underwent 13 different evaluations. We started with baseline assessments when they were inpatients at McLean, followed by a dozen more every two years. We also tracked general health outcomes, such as coexisting diseases, and strengths, such as grit and resilience.
Equally important, I had to develop relationships with the people who we followed. I still have many close relationships with participants in the study. I haven’t changed my voicemail in a quarter of a century, so people in the study could always find a way to reach me.
What were your initial impressions of the individuals you were following?
It was evident to me from early on that we had such an interesting group of participants. About half were young enough that they hadn’t married or started families yet. I could tell even from the beginning that they would do very well over time. And they have.
The other half of the participants had married very young, and some had young children, and they were struggling much more because the group that hadn’t married yet were able to focus more time and energy on getting well.
Mothers of young children had to focus on taking care of their kids, and that would prolong their condition and complicate disease course and treatment. That showed me that there were sociological factors involved in the trajectory of a person’s experience with BPD, which our research has come to confirm.
What have been some of the major findings revealed in the study?
I think the most seminal finding is that 100% of the people in our study achieved remission, and 77% achieved a 12-year remission. Our study shows that BPD personality is a highly treatable condition, and the treatment is psychotherapy, not medications.
We also found a substantially lower suicide rate than people had expected. This was not well-studied before our research, and the expectation among the medical community was a rate of about 10%. Ours, however, was 5.9%, and patients in our study were far more likely to die from a natural or accidental death. This reinforced that people with BPD who receive treatment can go on to lead long, healthy lives.
We have also found two more sobering yet important findings. The first is that only 60% of those with BPD attain recovery from BPD—meaning a concurrent symptomatic remission and good social and vocational functioning. The second of these findings is that the non-recovered men and women with BPD were significantly more likely to have poorer physical health than those who had achieved recovery.
When you look back at the study, what are you most proud of?
It has been very heartening to see the impact of this work in the BPD community and with that, an increased awareness and education among people diagnosed with BPD, their families, and their medical providers. With so much stigma involved in BPD, we’ve been able to correct misconceptions with our findings.
The field has advanced considerably since we began this study. Patients now are more likely to get the correct diagnosis right away, whereas prior, it might have taken five or 10 years to get the correct one, after getting misdiagnosed with bipolar disorder or PTSD. Once they get a diagnosis, BPD is no longer a dirty secret that families hide. Our research instead showed that it is the most treatable of any serious mental health disorder.
