(PS8-C62) The Dynamic Relationship Between Interpersonal Emotion Regulation and Borderline Personality Disorder Symptoms: Interactions with Three Brief Interventions

Emotion regulation difficulties and interpersonal dysfunction are key criteria for borderline personality disorder (BPD)(Lazarus et al., 2014; Linehan, 1993; Rosenthal et al., 2008). While dialectical behavior therapy (DBT) is the gold-standard treatment for BPD(Kliem et al., 2010; Linehan, 1993), DBT is lengthy and resource-intensive, hence diminishing its accessibility. Clarifying the effects of specific treatment components can streamline this treatment. Given the predominant role emotion regulation difficulties play within BPD, and the bidirectional relationship with interpersonal difficulties(Haliczer et al., 2021; Herr et al., 2013; Linehan, 1993), DBT emotion regulation skills may be a central component of treatment. Prior studies examining interpersonal emotion regulation difficulties in BPD have found greater interpersonal emotion regulation (I-ER) difficulties are associated with higher BPD symptoms; thus, I-ER may be an important mechanism to examine. The present study aimed to investigate the effects of I-ER and three treatment conditions (DBT emotion regulation and interpersonal effectiveness compared to an interpersonal psychotherapy module) on BPD symptoms. We hypothesized that six weeks of the DBT interpersonal skills module would decrease BPD symptoms. Moreover, we hypothesized that I-ER would be associated with BPD symptoms across treatment. Participants (N=84) were recruited from a university campus and surrounding community (M_age=25.1, SD=9.3, 98.7% female, 66.7% white) and met criteria for both BPD and recent recurrent self-injurious behaviors during a clinical diagnostic assessment. Participants were randomly assigned to receive a six-week module of emotion regulation, interpersonal effectiveness, or a non-skill-based control. Self-report measures of I-ER and BPD symptoms were collected at week 0, 3, and 6 of the treatment intervention. Multilevel models revealed there were no significant main effects of DBT conditions compared to the interpersonal condition on BSL-23 scores (ps >.573). However, there was a main effect of DIRE venting (b=.003, SE=.002, p=.048) and trend level main effect of DIRE reassurance seeking (b=.01, SE=.01, p</em>=.053) on BSL-23 scores during treatment. Consistent with these findings, reliable change indices demonstrate there were no differences across groups between baseline and treatment completion (p = .680), such that 22–33% of participants made reliable change on the BSL-23 between conditions. Our findings support that I-ER difficulties are associated with higher BPD symptoms during brief skills-based interventions. Future research should examine the interaction effects between I-ER and treatment on BPD symptoms over time.