• IRB CatSud, HUIPM and CIBERSAM contributed one of the cohorts that helped validate the findings
• The research, published in Nature Genetics, analysed data from nearly 13,000 people with the disorder and more than one million people without a diagnosis, from 14 countries

Borderline Personality Disorder (BPD) affects around 2% of the population in Western countries. It usually begins during adolescence and is diagnosed about three times more often in women than in men. The disorder is characterised by persistent instability in emotions, relationships and self-image, and is often linked to self-harming behaviours and a high risk of suicide. Despite its severity, there is currently no medication specifically approved to treat BPD, and its biological basis remains poorly understood.

Now, an international research consortium, with the participation of Hospital Universitari Institut Pere Mata (HUIPM) and the Institut de Recerca Biomèdica Catalunya Sud (IRB CatSud), has identified for the first time regions of the genome that are consistently associated with the disorder. Published in Nature Genetics, the study is the largest genetic analysis of BPD carried out to date and the first study of its kind on a personality disorder to produce conclusive results.

The research combined data from 27 clinical studies, biobanks and population cohorts from 14 countries. The project was coordinated by the Central Institute of Mental Health in Mannheim, Germany, within the framework of the Psychiatric Genomics Consortium. The Genetics and Environment in Psychiatry (GAP) research group, a joint initiative of HUIPM, IRB CatSud, Universitat Rovira i Virgili (URV) and CIBERSAM, contributed one of the two independent cohorts used to confirm the results obtained in the main analysis. Other CIBERSAM groups also took part, including teams from Hospital de la Santa Creu i Sant Pau and Hospital Universitari Vall d’Hebron.

The study identified a total of 11 regions of the genome and nine genes that may contribute to the development of the disorder. It also estimates that the common genetic variants analysed account for around 17% of susceptibility to BPD. These findings confirm that the disorder has a polygenic architecture, meaning that it results from the combined effect of many genetic variants, each with a small impact, similar to what has been observed in schizophrenia, depression and bipolar disorder.

The analysis also shows that the genetic risk linked to BPD overlaps considerably with that of other mental health conditions, particularly post-traumatic stress disorder, depression and attention-deficit/hyperactivity disorder (ADHD). Similar links were found with antisocial behaviour and measures related to suicide and self-harm. In addition, the study identified connections with physical health conditions such as chronic obstructive pulmonary disease (COPD), type 2 diabetes, obesity and hypertension. This finding is particularly important because a significant part of the reduced life expectancy observed in people with BPD is related to physical health problems. It also highlights the need for healthcare approaches that consider the individual’s overall health.

According to Elisabet Vilella, head of the Genetics and Environment in Psychiatry (GAP) research group, “these results show that BPD has a biological basis comparable to that of other severe mental disorders. This evidence should help reduce the stigma that still affects people living with the disorder and their families.”

The authors compare these findings to the early genetic studies of schizophrenia conducted around fifteen years ago, which initially identified only a few genomic regions before larger international collaborations and expanded sample sizes led to many more discoveries. They also point out two important limitations. First, all the samples analysed were of European ancestry, highlighting the need to extend research to more diverse populations. Second, the genetic risk scores derived from the study are research tools and cannot be used to predict an individual’s risk or to make clinical diagnoses. The data have been made available to the scientific community to support future studies and, in the long term, contribute to the development of new treatments.

Article reference

Streit, F., Awasthi, S., Hall, A. S. M., et al. Genome-wide association analyses of borderline personality disorder identify 11 loci and highlight shared risk with mental and somatic disorders. Nature Genetics (2026). Published 20 July 2026.

During the conference, strategic lines were discussed, such as promoting collaborative work, sharing data and knowledge, or creating a repository of genetic data, as well as the need to strengthen the transfer of results to clinical practice and society.

The meeting has represented a turning point in the field of genetics in psychiatry, since until now researchers specialised in the genetics of psychiatric disorders in the country had never met in a specific forum. In recent years, the growth of research in this field and the emergence of results with potential clinical application have favoured the consolidation of a critical mass that has made it possible to promote this initiative.

“It is the first conference held by specialist researchers in genetics of psychiatric diseases, and the reason is that it is a relatively innovative field. Over the years, the researchers we met at conferences said we had to do something together and, at the end of last October, at an international psychiatric genetics conference in Mexico, we decided to do it and chose to hold the first conference in Reus,” said the research director of HUIPM and deputy director of IRB CatSud, Elisabet Vilella.

At the conference, the different participating teams also shared their lines of work and presented the latest advances in genetics in psychiatry, with the aim of generating synergies and exploring new ways of collaboration. “Our group presented work related to the development and characterisation of neuronal lines from patients with first psychotic episodes, where we look for biological signals to help find the best diagnosis so that there can be the most personalised treatment possible, for example in the development of schizophrenia,” explained the researcher from the Instituto de Investigación Sanitaria de Valencia (INCLIVA), Ricardo Ruiz Miguel, one of the speakers at the conference.

The organisers also highlighted that initiatives like this help to accelerate the transfer of scientific knowledge into real applications and to promote collaboration between research groups, also incorporating work with patient associations as one of the key axes for the future.

With this first edition, the conference has laid the foundations to become a regular reference meeting at the national level, with the intention of continuing to strengthen scientific cooperation and to increase the impact of research in mental health for the benefit of society.