Hinton, & Gaynor, 2010

Cognitive defusion procedures, as used in acceptance and commitment therapy (ACT), attempt to alter how an individual relates to negative thoughts (without challenging, disputing, or trying to change their content) so as to promote psychological flexibility, the key feature of the ACT model of adaptive functioning. The current study examined the efficacy of three, once weekly, sessions of cognitive defusion (CD) compared to a concurrent waitlist (WL) condition for university students reporting elevated distress, dysphoria, and low self-esteem. Participants (N = 22) were randomized to CD or WL, with the latter offered CD following their WL participation. The combined data from all those offered CD were also compared to a supportive therapy benchmark established from archival data. Intent-to-treat analyses showed large changes in distress, depressive symptoms, self-esteem, defused awareness of thoughts, psychological flexibility, and automatic thoughts favoring CD over WL. These effects were replicated when the WL groups then received CD and persisted (or further improved) at 1-month follow-up. CD within-group effect sizes were also reliably larger than those derived from a  comparable supportive therapy condition. That CD was associated with significant changes in both outcome and process variables is consistent with the existing literature and with the view that cognitive defusion techniques (particularly vocalizing strategies) represent an active component of ACT. Future research employing more stringent concurrent controls, clinical samples, and multi method assessments that allow for temporally sequenced tests of mediators is needed to more fully substantiate the effects of cognitive defusion.