Abstract

A randomized clinical trial (RCT) was conducted to test the impact of Functional Analytic Psychotherapy (FAP) on individuals diagnosed with borderline personality disorder (BPD) who had finished treatment as usual (TAU) at a public institution in Mexico City. Two groups receiving 8 sessions of FAP (n=26) or Interpersonal Skills training (n=24) where compared. T-test analyses found statistically significant (p< 0.05) and large (Cohen’s d≥0.80) improvements for FAP group participants at post-test compared to pre-test in BPD symptom severity, intimacy, experience of self and emotion regulation. Between groups analysis found statistically significant and large effects in favor of FAP, with the largest differences observed in intimacy. Regression analysis found a reduction in the relation between intimacy and BPD severity before (R2=0.324) and after FAP treatment (R2=0.11). These results suggest FAP’s possible utility as an adjunct treatment for BPD.

Abbreviations: RCT: Randomized Clinical Trial; BPD: Borderline Personality Disorder; FAP: Functional Analytic Psychotherapy; TAU: Treatment as Usual; FIV: Inflated Variance Factor