Examining the role of cognitive fusion and experiential avoidance in predicting anxiety and depression

Objectives Acceptance and Commitment Therapy (ACT) proposes that cognitive fusion and experiential avoidance are inter-related processes underpinning distress. This study investigated whether worry, rumination, and stressful life events on the one hand and anxiety and depression on the other hand were mediated by cognitive fusion and experiential avoidance (bidirectional serial association). Design A questionnaire design was conducted cross-sectionally in a clinical sample (study 1; N = 57) and cross-sectionally and longitudinally in a non-clinical student sample (study 2; N = 106 and N = 97 respectively). Methods Participants completed measures of worry, rumination, stressful life events (predictors), cognitive fusion, experiential avoidance (mediators), anxiety, and depression (outcomes) at T1. In study 2, anxiety and depression were measured again 6 weeks later. Results In the clinical sample, the bidirectional relationship between experiential avoidance and cognitive fusion accounted for a significant proportion of the association between rumination and depression, and stressful life events and anxiety and depression. The association between worry and anxiety was mediated by cognitive fusion → experiential avoidance only. In the non-clinical sample, in both cross-sectional and longitudinal analyses, cognitive fusion independently mediated the association between predictors and outcomes, as well as the experiential avoidance → cognitive fusion pathway. Conclusions The bidirectional association between cognitive fusion and experiential avoidance was most predictive of distress in the clinical sample. In the non-clinical sample, cognitive fusion and the experiential avoidance → cognitive fusion pathway demonstrated more explanatory value. Given the cross-sectional nature of most of the data, the findings provide theoretical (as opposed to empirical) support for the models tested. Practitioner points Interventions designed to reduce cognitive fusion may be a useful early intervention for sub-clinical anxiety and depression. Interventions focused on reducing both cognitive fusion and experiential avoidance may be helpful for individuals presenting with clinical anxiety and depression. Individuals presenting with particularly high levels of experiential avoidance may benefit from initial work defusing from difficult thoughts, as an inroad for reducing experiential avoidance, anxiety, and depression. Likewise, those with rigid cognitive fusion may benefit from initial work around acceptance skills to create a context that better supports defusion.