Factors influencing the success of exposure therapy for specific phobia: A systematic review

Although Exposure Therapy (ET) is the first-line treatment of Specific Phobia (SP), there is no clear consensus on which factors influence its success, and thus on how to conduct it most efficiently. This review summarizes the current state of research regarding this topic. N = 111 studies were in accordance with our eligibility criteria: participants had at least symptoms of SP, the intervention was ET and the study investigated a factor influencing its success. Best evidence for positive effects was found for low trait anxiety, high motivation and high self-efficacy before the ET, high cortisol levels and heart rate variation, evoking disgust additionally to anxiety, avoiding relaxation, focusing on cognitive changes, context variation, sleep, and memory-enhancing drugs. These factors may be conceptualized as modulating different aspects of learning as suggested in current models of ET that focus on inhibitory learning mechanisms. Limitations lie in the great heterogeneity concerning operationalization of factors and success. Based on these findings, we make suggestions for improvements in ET conduction and which factors should be researched in the future.