Conformity to prototypical therapeutic principles and its relation with change in reflective functioning in three treatments for borderline personality disorder

To examine conformity to prototypical therapeutic principles and its relation with change in reflective functioning in 3 treatments for borderline personality disorder (BPD).Early phase videotaped sessions from a randomized-controlled trial of year-long transference-focused psychotherapy (TFP; n = 27), dialectical behavior therapy (DBT; n = 26), and supportive psychodynamic therapy (SPT; n = 29) were coded using the Psychotherapy Q-sort (Jones, 1985). Ratings were compared to experts' ratings of ideal TFP, DBT, and mentalizing-enhancing principles to quantify conformity to ideal treatments. Reflective functioning was assessed at pre- and posttreatment. Differences among treatments in conformity and its relation with change in reflective functioning were examined.Conformity to TFP and mentalizing-enhancing principles was highest in TFP (ps.01) while conformity to DBT principles was high in DBT and SPT (DBT vs. SPT: p.40), but lower in TFP (ps.01). Larger improvements in reflective functioning were predicted by higher conformity to TFP principles during TFP (p = .04) and higher conformity to mentalizing-enhancing principles during SPT (p = .02).Treatments for BPD differ in conformity to unique principles of specific modalities. Treatments also differ in the processes that predict increase in reflective functioning. The findings point to specificity and multiple pathways in increasing reflective functioning in the treatment of BPD. (PsycINFO Database Record (c) 2019 APA, all rights reserved).