Abstract
BACKGROUND: Skills training is believed to be essential in dialectical behavior therapy (DBT) and is also offered as a standalone intervention. There is a need to better understand each skills module's separate contribution to treatment outcomes. Several assessment instruments are available, but none of them provides specific information about patients' perceived ability to use skills promoting distress tolerance. The aim of the present study was to develop and evaluate the psychometric properties of a Swedish adaptation of the General Self-Efficacy scale (GSE) for skills use in distress tolerance - the Self-Efficacy in Distress Tolerance scale (SE-DT). METHODS: Cross-sectional and longitudinal data were gathered in a non-clinical (NC) community sample (n = 407) and a clinical psychiatric (CP) sample (n = 46). Participants in the NC sample were asked to complete a set of 19 self-report instruments, including the SE-DT, and 45 participants repeated the assessment after 2 weeks. The patients in the CP sample filled out a subset of eight instruments; twenty patients repeated the assessment after completing a treatment intervention including mindfulness skills and distress tolerance skills or emotion regulation skills. RESULTS: The analyses showed that the SE-DT is unidimensional with high internal consistency (Cronbach's alpha = .92) and good test-retest reliability (intraclass correlation = .74). The SE-DT also showed good convergent and divergent validity, demonstrating positive correlations with general self-efficacy and self-compassion, and negative correlations with difficulties in emotion regulation, psychiatric symptoms, and borderline symptoms. The SE-DT showed sensitivity to change, when pre- and post-treatment assessments were compared (Cohen's d = 0.82). DISCUSSION: This is preliminary evidence that the SE-DT has adequate to good psychometric properties, supporting the use of a total sum score. The results indicate that the SE-DT can adequately measure the construct of self-efficacy with regard to dealing with distress and emotional crises. The instrument enables continued investigation of standalone skills training and the specific contribution of distress tolerance skills to treatment outcomes in DBT. Further studies are needed to investigate whether these results are valid in other populations. In addition, the field would benefit from a common definition of distress tolerance.