Background: Little is known about the "active ingredients" of psychological therapy for Borderline Personality Disorder (BPD) despite a growing evidence base documenting its clinical effectiveness. This information can be used by clinicians to inform service planning and care pathways.Aims: The aim of this study was to review published empirical research investigating the potential mechanisms underlying therapeutic change in Dialectical Behaviour Therapy (DBT) and Cognitive Behaviour Therapy (CBT) for BPD.Method: A thorough search of the PsychInfo, CINAHL Plus, PubMed, MEDLINE and EMBASE databases revealed research into potential mechanisms of change.Results: A total of 52 abstracts were reviewed. After a full text screen of the most relevant studies, 14 met inclusion criteria. Twelve examined DBT and two CBT. Mechanisms of change identified broadly fell into three categories: emotion regulation/self-control, skills use and therapeutic alliance/investment in treatment. Outcomes measured included general mental health diagnoses (e.g. anxiety, depression) and BPD-specific symptoms (e.g. self-harm/suicidality, impulsivity, substance misuse, anger).Conclusion: Further empirically robust research is required to test hypotheses about the influence of the proposed mechanisms on therapeutic change in psychological therapies for BPD.
Keywords: Borderline personality disorder; CBT; DBT; outcomes; therapeutic change.