(PS3-86) The Inhibitory Learning Approach to Exposure Therapy: A Comparison of Treatment Outcomes

Exposure therapy is a commonly used, effective therapy for individuals with anxiety and other fear-based disorders (e.g.,  OCD, PTSD). Traditionally, exposure therapy has been conducted in accordance with emotional processing theory (EPT), which focuses on fear reduction as measured by initial fear activation as well as within- and between-session habituation. However, many individuals do not respond to traditional exposure therapy, and some researchers argue that habituation is an unreliable measure of symptom change. Recent literature has suggested that exposure based on an inhibitory learning approach may lead to more successful outcomes following treatment. Despite a strong theoretical rationale supporting this notion, there is a paucity of corroborating data, particularly in a naturalistic treatment setting. The current study aims to assess if the inhibitory learning approach leads to better therapeutic outcomes compared to the emotional processing model of exposure therapy. The sample includes 2,044 individuals (female: 61.4%; male: 37.7%; other: 0.8%) seeking treatment for obsessive-compulsive (68.4%) and other anxiety related disorders (31.5%) at two affiliated clinics in the Southwest region of the United States. Participants underwent an intensive outpatient program, which included CBT with an emphasis on exposure. In September 2019, exposures shifted from being conducted in accordance with the EPT model to the inhibitory learning approach. Symptom reduction, as measured via self-report assessments at pre- and post-treatment timepoints was compared between the two models using an interrupted time series (ITS) analysis. Graphical depictions of the ITS analysis demonstrate that when using traditional exposure therapy models, the average symptom reduction was 42.6%, and following the implementation of inhibitory learning exposures, the trend in symptom reduction scores increases (M=49.3%). Stated differently, participants who were treated with inhibitory learning exposures reported greater reductions in symptoms compared to those who received the emotional processing approach to exposure therapy. This finding demonstrates that the inhibitory learning approach to exposure therapy may lead to greater therapeutic gains than traditional models and underscores the benefit of adopting this approach across settings to promote more successful outcomes.