A systematic review of neurobiological aspects of borderline personality disorder among adolescent patients

Background: Borderline personality Disorder is a complex mental health condition with disturbances in emotions, self-perception, and relationships. Emerging in adolescence, it reaches its peak in early adulthood, impacting 1 %-3 % of individuals. Methods: We documented this review in PROSPERO with the registration code CRD4202126220. Subsequently, we conducted a comprehensive search across Pubmed, PsycINFO, Medline, Embase, Web of Science and Scopus databases. A systematic synthesis focusing on the neurobiological foundations of borderline personality disorder is presented. Results: A total of 22 studies and 1400 participants were included. Most of the studies 10/22 and 4/22 were from Australia and Germany, respectively. Genetic findings linked the short allele of 5-HTTLPR to the elevated borderline personality disorder traits and revealed neuroendocrine alterations. While imaging studies documented structural brain changes in areas such as the dorsolateral frontal gyrus and hippocampus, and reduced volumes in the anterior cingulate cortex and corpus callosum. Electrophysiological studies indicated abnormal cerebral maturation with diminished P300 amplitudes and increased alpha phase synchrony in borderline personality disorder adolescents, particularly during emotional tests. Conclusion: We concluded that while borderline personality disorder symptoms may endure from adolescence into adulthood, existing evidence lacks consistency in neurobiological findings. Differences in the prefrontal cortex, orbitofrontal cortex, amygdala and hippocampus showed potential significance, however, electrophysiological, biochemical and genetic presented insufficient generalizable evidence for adolescents. Longitudinal studies and further investigation are needed.