How Interpersonal Psychotherapy Changes the Brain: A Study of fMRI in Borderline Personality Disorder.

Background: Recent guidelines and systematic reviews suggest that disorder-specific psychotherapeutic interventions are the first choice in the treatment of borderline personality disorder (BPD). The aim of this study is to examine brain activity changes in BPD patients (DSM-5) who received a revised BPD-adapted interpersonal psychotherapy (IPT-BPD-R) compared with patients on the waiting list.Methods: Forty-three patients with a BPD diagnosis (DSM-5) were randomly assigned to IPT-BPD-R (n = 22 patients) or the waiting list with clinical management (n = 21 patients) for 10 months. Both groups were tested before and after treatment with the Social and Occupational Functioning Assessment Scale (SOFAS), the Clinical Global Impressions-Severity of Illness scale (CGI-S), the Borderline Personality Disorder Severity Index (BPDSI), the Barratt Impulsiveness Scale-version 11 (BIS-11), and the Autobiographical Interview. Both groups underwent pre- and posttreatment functional magnetic resonance imaging (fMRI) testing. The fMRI task consisted of the presentation of resolved and unresolved life events compared to a neutral condition. All structural and functional images were analyzed using Statistical Parametric Mapping 12 software, which interfaces with MATLAB. Clinical data were analyzed using analysis of variance for repeated measures. Patients were recruited between September 2017 and April 2019.Results: In clinical results, for the 4 rating scales, a significant between-subject effect was found in favor of the IPT-BPD-R-treated group (CGI-S: P = .011; BPDSI: P = .009; BIS-11: P = .033; SOFAS: P = .022). In fMRI results, posttreatment versus pretreatment for the contrast unresolved life event versus neutral condition showed significantly decreased right temporoparietal junction (rTPJ: x = 45, y = -51, z = 36) (P = .043) and right anterior cingulate cortex (rACC: x = -4, y = 37, z = 8) activity (P = .021).Conclusions: IPT-BPD-R appears to be effective in treating BPD symptoms, and these clinical effects are reflected in the functional changes observed with fMRI. Brain areas that showed modulation of their activity are the rTPJ and rACC, which are involved in mentalization processes that are fundamental to BPD pathology.Trial Registration: Australian New Zealand Clinical Trials Registry (ANZCTR) code: ACTRN12619000078156.