Diazepam binding inhibitor and dehydroepiandrosterone sulphate plasma levels in borderline personality disorder adolescents

Background: Borderline personality disorder (BPD) patients display a complex and heterogeneous clinical phenotype that plausibly implies variable underlying pathogenic mechanisms. A dysregulation of peripheral benzodiazepine receptors has previously been shown in BPD peripheral tissues, implying possible alterations of its ligand, the diazepam binding inhibitor (DBI) or of the downstream products of its activation, i.e. neuroactive steroids. Methods: The aim of this work consisted in assessing, by ELISA, fasting plasma levels of DBI and dehydroepiandrosterone sulphate (DHEA-S), including cortisol and the cortisol-to-DHEA-S molar ratio (CDR), in 17 BPD adolescents versus 13 healthy controls, testing the possibility that clinical scales related to depressive or anxious traits (CDI, STAI-Y) or to disease severity (BPDCL) might be associated with a selective dysregulation of these parameters. Results: DBI plasma levels were unchanged, while DHEA-S ones were significantly increased (approx. 70%) and the CDR decreased in BPD patients. No meaningful correlations with clinical variables emerged. Conclusion: Our results indicate that a dysfunction of the neurosteroid system might be operative in BPD in spite of unchanged DBI plasma levels and that DHEA-S might represent a generalized trait marker for the altered stress response that is associated with this disorder.