Acceptance -based emotion regulation, perceptions of control, state mindfulness, anxiety sensitivity, and experiential avoidance: Predicting response to hyperventilation

Acceptance- and mindfulness-based approaches to anxiety have recently received increased attention and empirical support. Little is known, however, about the mechanisms of such interventions and further study is needed to determine the conditions under which such approaches are warranted. The current study experimentally investigated two possible mediators (i.e., perceived control; mindfulness) of acceptance based coping instruction on fear responding in nonclinical participants who underwent voluntary hyperventilation. Selected relationships between experiential avoidance (EA), anxiety sensitivity (AS), coping strategy choice, both mediators, and anxious responding were also examined in a no instruction comparison condition. It was expected that participants in the acceptance condition, compared to the no instruction group, would exhibit less avoidance behavior and subjective anxiety in response to hyperventilation. An increase in perceived control was predicted to mediate the relationship. The alternative mediator hypothesis was that increased state mindfulness (i.e., curiosity; decentering) or increased emotional willingness would mediate the effect. In the no instruction condition, AS and EA were expected to be positively associated with fearful responding as well as the utilization of avoidance-based coping strategies, which were in turn expected to be positively associated with subjective distress. An association between lower levels of mindfulness and perceived control and elevated levels of AS and EA was anticipated. Despite significant change and/or between-group differences in measured mediators, the acceptance coping manipulation did not produce any significant between-group differences in indexes of fear of avoidance. Exploratory analyses indicated, however, that use of acceptance coping was prospectively associated with decreased behavioral avoidance of the second hyperventilation across the sample. Though both the acceptance manipulation and use of acceptance-based coping were positively associated with facets of state mindfulness (i.e., decentering), the post-hoc effect of acceptance-based coping on avoidance was mediated by a willingness to experience emotions and symptoms during initial hyperventilation. Modest support for most of the no instruction group hypotheses was indicated. Experimental findings were discussed in terms of the comparison group, which used predominantly acceptance-based strategies, and the relatively unselected college student sample. Implications and findings were discussed with an emphasis on acceptance-based coping, state mindfulness, perceived control, and avoidance-based coping.