An examination of mindfulness as a predictor of treatment outcome in dialectical behaviour therapy self-help for binge-eating disorder

Background: Binge eating disorder (BED) is the most prevalent eating disorder and is associated with significant psychosocial impairment and medical complications. Most individuals with BED do not receive evidence-based treatment (EBT) and face barriers, such as stigma and limited access to resources. Dialectical behaviour therapy (DBT) is one of the few EBTs for BED and conceptualizes binge eating as a maladaptive emotion regulation strategy. A self-help version of DBT has been developed to increase treatment accessibility with promising results. However, little is known about the mechanisms through which DBT self-help (DBT-SH) works for BED. Mindfulness is a core tenet of DBT and warrants investigation as a potential mechanism of change. Mindfulness skills training in DBT for BED aims to enable individuals to practice awareness and acceptance of internal experiences, which may allow them to engage in more adaptive emotion regulation strategies. The goal of the present study was to examine mindfulness as a predictor of change in DBT-SH treatment outcome for BED. Method: The current study is a secondary analysis of data from a randomized controlled trial (RCT) of DBTSH for BED. Seventy-one adults meeting criteria for BED were randomized to 12 weeks of DBT-SH or an active self-help control condition. Binge-eating frequency, eating disorder psychopathology, mindfulness, and global distress were measured at baseline, post-treatment, and 3 months post-treatment. Results: Improvement in mindfulness did not differ between DBTSH and the active control condition. There was a significant association between improvement in mindfulness and reduction in eating disorder psychopathology from pre- to post-DBT-SH treatment with a medium effect size. Contrary to expectations, there was no significant association between improvement in mindfulness and reduction in binge-eating frequency. Baseline mindfulness did not predict changes in binge-eating frequency or eating disorder psychopathology. Discussion: The findings of the current study suggest that mindfulness may have more of an impact on the cognitive aspects of eating disorder psychopathology than on binge-eating behaviour. Methodological limitations such as a relatively small sample size and low statistical power may have impacted results. Further research is needed to clarify the role of mindfulness in DBT-SH outcome for BED. Future research on the integration of mindfulness-based and behavioural treatment approaches could provide a more effective treatment for BED.