Schema modes as mechanisms of change in treating borderline personality disorder A model replication study

Objective: Schema modes have been theorized and tested as mechanisms of change in the treatment of personality disorders. We investigated whether schema modes also function as mechanisms of change in borderline personality disorder (BPD) treatment. Method: Data from 494 patients (N = 68 male, N = 426 female) with borderline PD who participated in an international randomized clinical trial on effectiveness of two group schema therapy formats vs treatment as usual were analyzed. Granger Causality was tested partially replicating the model predicting PD severity as derived in Yakın et al. (2020) with generalized linear mixed models, testing within-person relationships over time. Results: The effect of the Healthy Adult, the Vulnerable Child and Detached Self-Soother as an Avoidant Coping mode on PD severity, and the reciprocal relationship between the Healthy Adult and the Vulnerable Child were replicated. Unlike previous findings, the Avoidant Coping mode is not predicted by the Healthy Adult. Moreover, the relationship between Impulsive Child and PD severity was unidirectional. The relationships between Healthy Adult, Self-Aggrandizer, and functioning over time were also replicated, but unlike earlier results, Self-Aggrandizer did not influence later scores of the Healthy Adult. Conclusions: Central relationships in the model were replicated. The centrality of the Healthy Adult and the Vulnerable Child for the treatment of PDs was also applicable to BPD. It appears that these two modes should be primary treatment targets compared to the other modes, unless the avoidant modes block access to the more vulnerable parts of the personality.