Incremental Validity of Cognitive-Behavioral Therapy and Acceptance and Commitment Therapy Mechanisms for Anxiety and Panic Symptomology.

Background: acceptance and commitment therapy (ACT) and cognitive-behavioral therapy (CBT) are empirically supported treatments for anxiety and panic disorder (PD), though they differ in their putative vulnerability and maintenance processes. The present study examined the incremental validity of several of these models' proposed core processes, including anxiety sensitivity (AS), dispositional avoidance, experiential avoidance (EA), cognitive fusion (CF), and mindfulness, as well as the interaction of the processes within each model, in the prediction of anxiety and panic symptomology. Methods: a sample of US adults (n = 316) completed self-report measures of AS, dispositional avoidance, EA, CF, mindfulness, anxiety, and PD symptoms. A series of hierarchical multiple regression analyses were conducted. Results: hierarchical regression analyses indicated that AS, dispositional avoidance, and EA predicted anxiety and panic symptoms even after controlling for one another, CF, mindfulness, and demographic variables. Although mindfulness and CF was correlated with anxiety and panic at the univariate level, they did not predict either outcome above and beyond AS, dispositional avoidance, and EA. When interaction terms were added to the models, the interaction between AS and -dispositional avoidance was a significant predictor of panic and anxiety symptoms, whereas the interaction between EA and CF only predicted panic symptoms. None of the interactions that included mindfulness were significant predictors. Conclusions: these findings provide support the independent and interactive predictive value of traditional CBT (AS, dispositional avoidance, and AS-dispositional avoidance) and ACT (EA) processes for anxiety and panic symptoms, but raise questions about the incremental predictive utility of CF and mindfulness.