Abstract
Dialectical behavior therapy (DBT) is an extensively studied treatment for borderline personality disorder (BPD), with skills use being one of the hypothesized mechanisms of change. Research has previously been hindered by the absence of an appropriate tool to measure skills use, leading to the development of the DBT Ways of Coping Checklist (DBT-WCCL). The DBT-WCCL aims to assess DBT skills use (DSS) as well as dysfunctional coping (DCS), which can be divided into dysfunctional coping in general (DCS1) and blaming others (DCS2). This study evaluated the Dutch version of the DBT-WCCL by examining (1) the dimensional structure and measurement invariance across BPD and non-clinical samples, (2) psychometric properties (reliability and validity), and (3) sensitivity to change. A total of 204 participants diagnosed with BPD and 103 non-clinical controls completed the Dutch DBT-WCCL along with instruments assessing emotion regulation and BPD manifestations. First, when including all DBT-WCCL items, the hypothesized two-factor and three-factor models were not tenable due to substantial content overlap. When factor analyses included only items representing DBT skills or dysfunctional coping, support was found for three subscales (DSS, DCS1, and DCS2). Partial measurement invariance was established only for the DSS subscale. Reliability and known-group validity were satisfactory for all scales, while inconclusive results were found for the concurrent validity of the DSS subscale. Finally, the DBT-WCCL proved to be sensitive to change. In conclusion, our findings largely support the use of the Dutch DBT-WCCL, but warrant caution when comparing samples on dysfunctional coping. Trial Registration: The BOOTS study was registered in the Overview of Medical Research in the Netherlands (NL-OMON21337).