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

Background Recent guidelines and systematic reviews suggested that disorder-specific psychotherapeutic interventions are first-line treatments for borderline personality disorder. This study is aimed to evaluate changes of brain activity in BPD patients (DSM-5) who received interpersonal psychotherapy adapted to BPD-revised (IPT-BPD-R) in comparison with patients who were in waiting list (WL). Methods Forty-three subjects with a BPD diagnosis (DSM-5) were randomly assigned to IPT-BPD-R (N = 22 patients) or waiting list with clinical management (N = 21 patients) for 10 months. Both groups were tested before and after treatment with the CGI-S, the BPDSI, the BIS-11, and the Autobiographical Interview. Both groups underwent a pre-treatment fMRI run and a post-treatment fMRI run. fMRI task consisted of presentation of resolved and unresolved life events compared with a neutral condition. We analyzed all structural and functional images using Statistical Parametric Mapping 12 software interfaced on Matlab. Clinical data were analyzed with the ANOVA for repeated measures. Patients were recruited from September 2017 and April 2019. Results Clinical results: significant between-subjects effect was found for the four rating scales in favor of the IPT-BPD-R treated group (CGI-S: P = 0.009; BPDSI: P = 0.01; BIS-11: P = 0.031; SOFAS: P = 0.02). fMRI results: Post versus Pre for the contrast unresolved life event condition versus neutral condition showed a significantly decreased activity of the right Temporal Parietal Junction (rTPJ, x = 45, y = -51, z = 36) (P = 0.043) and of the right Anterior Cingulate Cortex (rACC, x = -4, y = 37, z = 8) (P = 0.021). Conclusions: IPT-BPD-R appears to be effective in treating BPD symptoms and these clinical effects are reflected in functional changes observed with fMRI. Brain areas that showed a modulation in their activity are TPJ and ACC, that are involved in mentalization processes fundamental in BPD pathology. The trial was registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) and allocated the code: ACTRN12619000078156.