Symposia
Personality Disorders
Maya E. Amestoy, PhD
University of Toronto
Thornhill, Ontario, Canada
Tahira Gulamani, MA
Student
University of Toronto Scarborough
Toronto, Ontario, Canada
Amanda A. Uliaszek, Ph.D.
Associate Professor
University of Toronto
Toronto, Ontario, Canada
Tayyab R, p
p
University of Toronto Scarborough
Toronto, Ontario, Canada
Dialectical Behaviour Therapy (DBT) skills group targets distress tolerance, mindfulness, and emotion regulation as putative mechanisms of action in achieving desired treatment outcomes. Only limited research has demonstrated that these skills improve throughout DBT treatment and little is known as to whether these effects are specific to DBT or are related to other evidence-based group treatments focused on similar populations. The aim of this study was to investigate improvement over time and group differences in these skills in 56 transdiagnostic clients randomized to either a 12-week DBT or positive psychotherapy (PPT) treatment group. Distress tolerance, mindfulness, and emotion regulation were assessed at pre-and post-treatment utilizing the Distress Tolerance Scale (DTS), the observing, describing, awareness, and accepting subscales of the Kentucky Inventory of Mindfulness Skills (KIMS), and the six subscales of the Difficulties in Emotion Regulation Scale (DERS; nonacceptance, goals, impulse control, emotional awareness, strategies, and clarity). Analyses include repeated measures ANOVAs within subscale and predicted by type of group therapy. Results indicated that the only the DBT skills group elicited a statistically significant change in the DTS over time (Cohen’s d = .68); however, a significant interaction was not observed. There were no statistically significant interactions on the observing, describing, awareness, or acceptance subscales of the KIMS. However, only the DBT skills group showed statistically significant improvements in all mindfulness subscales over time (Cohen’s ds = .97, .84, .59, and .73, respectively). With regard to emotion regulation, results demonstrated statistically significant changes in non-acceptance, impulse control, awareness, strategies, and clarity among the DBT group only (Cohen’s ds = .66-.1.17). No significant interaction effects were observed for any of the DERS subscales. While the PPT group did not demonstrate significant levels of change on any of the study variables, this group did exhibit small effect size changes on many variables in the expected direction. These preliminary findings suggest evidence for target validation of the modules of DBT group; likely, this indicates that changes in distress tolerance, mindfulness, and emotion regulation are mechanisms of change in DBT specifically. Positive outcomes in the PPT group are likely due to differential mechanisms. Implications for future research and treatment are discussed.