Examination of the Benefits of Inhibitory Retrieval Strategies and Associated Mechanisms in Exposure-Based Interventions

Abstract

Exposure therapy is partially based on extinction principles and is considered a core component of treatment for anxiety-related disorders. However, a common limitation of exposure is that fear often returns following successful treatment. Informed by the inhibitory retrieval model, exposure augmentation strategies have been proposed to increase learning and decrease subsequent return of fear. However, the extent to which these inhibitory retrieval strategies enhance human fear extinction and traditional exposure therapy remains unclear. Study 1 critically examines human fear conditioning and exposure-based interventions that compared extinction/exposure with and without an inhibitory retrieval strategy. Findings from this qualitative and meta-analytic review suggest the benefits of inhibitory retrieval strategies translate from human fear conditioning studies to exposure-based therapies. However, it remains unknown which inhibitory retrieval strategies most effectively attenuate return of fear. Study 2 demonstrates that occasional reinforcement is one such strategy that significantly weakens behavioral return of fear at a one-week follow-up, and that mean distress mediates this behavioral change. Study 3 expands upon these findings by examining the comparative efficacy of occasional reinforcement with another inhibitory retrieval strategy, affect labeling. Findings suggest that compared to occasional reinforcement, affect labeling during exposure results in less behavioral approach at post-exposure and follow-up, and this difference is partially mediated by distress variability and within-session habituation. Although studies 2 and 3 provide insight into which inhibitory retrieval strategy may be most promising, these strategies often combine exposure to multiple-contexts and exposure to multiple-stimuli. To clarify which approach may maximize therapeutic effects, study 4 examines the efficacy of exposure to multiple-contexts, exposure to multiple-stimuli, and their combination. Results suggest that exposure to multiple contexts and multiple-stimuli effectively decrease negative threat expectancies but may be detrimental when combined without sufficient repetition. Future directions for translational exposure-based research, including measurement selection and prescriptive indicators for treatment are discussed.