Changes in Emotion Regulation During the Course of Dialectical Behaviour Therapy: Effects on Non-Suicidal Self-Injury and Binge Eating Across Two Samples

Dialectical Behaviour Therapy (DBT) has demonstrated effectiveness in reducing harmful behaviours associated with emotion dysregulation, including non-suicidal self-injury (NSSI) and binge eating. It has been hypothesized that the effects of DBT on NSSI and binge eating are the result of improvements in emotion regulation (ER); however, the extent to which changes in ER account for reductions in these behaviours is unclear. The present study leverages two unique clinical samples to examine the degree to which changes in ER influence changes in the frequency of NSSI and binge eating over the course of DBT. Participants included 189 Veterans receiving outpatient DBT and 117 civilians enrolled in a DBT Intensive Outpatient Program. Analyses examined changes in ER, binge eating and NSSI over the course of treatment, as well as the extent to which NSSI and binge eating frequency were influenced by changes in ER. In the Veteran sample, DBT led to improvements in ER abilities and significant reductions in NSSI and binge eating; however, changes in ER did not account for observed reductions in NSSI or binge eating. In the civilian sample, the effects of DBT on ER, NSSI and binge eating were nonsignificant. Our findings suggest that ER may not be the only mechanism through which DBT exerts its effects on NSSI and binge eating. The effects of DBT on ER and self-damaging behaviours may vary based on factors such as treatment setting, time in treatment and clinical severity of the sample.