Borderline personality disorder in youth linked to altered brain activation during self-identity processing

A new neuroimaging study suggests that adolescents with borderline personality disorder exhibit distinct patterns of brain activity when reflecting on their own identity. The findings indicate that these young patients show reduced activation in the dorsolateral prefrontal cortex, a region associated with cognitive control, compared to healthy peers. This research was published in Translational Psychiatry.

Borderline personality disorder is a serious mental health condition. It is characterized by pervasive instability in moods, interpersonal relationships, self-image, and behavior. A central feature of this disorder is a disturbed sense of identity. Individuals often experience shifting goals, values, and vocational aspirations. This instability can manifest early in the course of the disorder.

Many previous studies have investigated the biological roots of the condition. Most of research has focused on emotional dysregulation rather than identity disturbance. Existing functional imaging studies have typically involved adult patients. These adult participants often have a history of medication use or co-occurring psychiatric conditions. These factors can make it difficult to determine which brain abnormalities are specific to borderline personality disorder itself.

To address this gap, a research team led by Pilar Salgado-Pineda from the FIDMAG Germanes Hospitalàries Research Foundation in Barcelona designed a study focusing on adolescents. They specifically sought participants who were in the early stages of the disorder. The team aimed to identify brain regions involved in the identity disturbance seen in the disorder. They focused on a developmental period that is critical for the formation of social cognition and self-concept.

The researchers recruited 27 female adolescents diagnosed with borderline personality disorder. These participants were between the ages of 12 and 18. Crucially, none of the patients had ever received pharmacological treatment for their condition. They were also screened to ensure they did not have any other comorbid psychiatric disorders.

For the control group, the researchers recruited 28 healthy female adolescents. These controls were matched to the patients in terms of age and estimated intelligence quotient. The strict selection criteria aimed to minimize confounding factors such as drug treatment and long-term illness effects.

The participants underwent functional magnetic resonance imaging. This technology measures brain activity by detecting changes associated with blood flow. While inside the scanner, the participants performed a task designed to engage self-reflection and reflection on others.

The task involved viewing a series of statements. Participants were asked to evaluate whether these statements were true or false. The statements belonged to one of three categories. The first category was the “self” condition, consisting of sentences about the participant. The second was the “other” condition, which involved sentences about an acquaintance the participant knew but was not emotionally close to.

The third category was a “facts” condition. This served as a control task and included general knowledge statements. The researchers also included a low-level baseline period where participants simply looked at a fixation cross on the screen. This design allowed the researchers to isolate brain activity specific to thinking about oneself and thinking about others.

The researchers analyzed the brain imaging data by comparing activation patterns between the different conditions. They specifically looked at the contrast between self-reflection and fact-processing. They also examined the contrast between other-reflection and fact-processing.

The analysis revealed differences in the group with borderline personality disorder during the self-reflection task. When comparing self-reflection to fact-processing, the healthy controls showed activation in several specific brain areas. These included the medial frontal cortex and the dorsolateral prefrontal cortex.

In contrast, the patients with borderline personality disorder showed reduced activation in the right dorsolateral prefrontal cortex. The patients also exhibited reduced activation in the left parietal cortex, the calcarine cortex, and the right precuneus.

The researchers conducted further analyses to understand the direction of these changes. They examined the activity levels in these regions relative to the fixation baseline. This revealed that while healthy controls activated the right dorsolateral prefrontal cortex during self-reflection, the patient group actually showed deactivation in this area.

The dorsolateral prefrontal cortex is widely recognized for its role in executive functions. It is heavily involved in top-down cognitive control. The authors suggest that the reduced activation in this region may reflect a diminished capacity for cognitive control over the process of self-reflection.

The study also examined brain activity during the other-reflection task. The results showed a different pattern of abnormality. When comparing other-reflection to fact-processing, the patient group appeared to show reduced activation in the medial frontal cortex. This region is part of the default mode network.

However, a detailed inspection of the data offered a nuanced explanation. The difference was not due to how the patients processed information about others. Instead, it was driven by a difference in the fact-processing condition. The healthy controls showed strong deactivation of the medial frontal cortex during the fact task. The patients failed to deactivate this region to the same extent.

The researchers interpret this specific finding as a failure of deactivation rather than a deficit in social cognition. This suggests that the brain mechanisms for thinking about others may be relatively preserved in these adolescents. The abnormality lay in the inability to suppress certain brain networks during a factual cognitive task.

The study notably found no differences between the groups in the temporoparietal junction. This brain region is known to be involved in understanding the beliefs of others. The lack of difference here implies that some aspects of social cognition might function normally in adolescents with the disorder.

There are limitations to this study that contextualize the findings. The sample included only female participants. Borderline personality disorder is diagnosed more frequently in females, but it does affect males. The findings may not extend to male adolescents with the condition.

The sample size was relatively small, with fewer than 30 participants in each group. Neuroimaging studies often require larger samples to detect subtle effects reliably. The strict exclusion criteria also limit generalizability. Most people with borderline personality disorder have other mental health conditions. Studying a “pure” sample helps isolate biological mechanisms but may not reflect the typical clinical population.

The study also relied on a specific experimental task to measure self-reflection. While this task is established in the field, it serves as an indirect measure of identity disturbance. The researchers did not include a behavioral measure of identity problems to correlate with the brain data.

Future research is needed to replicate these findings in larger and more diverse groups. Longitudinal studies could be particularly informative. Tracking adolescents over time would help clarify whether these brain activity patterns predict the worsening or improvement of symptoms as they enter adulthood.

The study, “Brain functional abnormality in drug naïve adolescents with borderline personality disorder during self- and other-reflection,” was authored by Pilar Salgado-Pineda, Marc Ferrer, Natàlia Calvo, Juan D. Duque-Yemail, Xavier Costa, Àlex Rué, Violeta Pérez-Rodriguez, Josep Antoni Ramos-Quiroga, Cristina Veciana-Verdaguer, Paola Fuentes-Claramonte, Raymond Salvador, Peter J. McKenna, and Edith Pomarol-Clotet.