Enhancing Exposure Therapy for Snake and Spider Phobias

This study tests whether exposure therapy for fear of snakes or spiders is enhanced by the addition of a brief fear retrieval trial prior to treatment, and the use of compound extinction during treatment. The goal of the study is to determine whether these behavioral techniques enhance the efficacy of exposure therapy, one of the most empirically supported treatments for anxiety disorders. Individuals between the ages of 18-65 with elevated fear of spiders or fear of snakes are randomly assigned to one of four treatment conditions (1) standard exposure therapy, (2) exposure therapy with fear retrieval augmentation, (3) exposure therapy with compound extinction augmentation, and (4) exposure therapy with fear retrieval and compound extinction augmentations. All participants undergo an online prescreen and a face-to-face screening assessment to determine eligibility and baseline (pre-treatment) symptom severity. Participants additionally complete assessments directly after treatment (post-treatment), and approximately one week after treatment (follow-up). The pre-treatment assessment occurs 1-14 days prior to treatment, the post-treatment assessment occurs during the treatment visit as soon as the treatment procedure is complete, and the follow-up assessment occurs within a window of 6-14 days after the completion of treatment. Participants complete two behavioral approach tests (in the treatment context and in the generalization context) at pre-treatment, post-treatment, and follow-up. Participants complete a battery of self-report questionnaires at pre-treatment and follow-up.

Inclusion criteria

• Age 18 to 65.
• Speaks English fluently.
• A score of 70 or higher on the Fear of Snakes/Spiders Questionnaire.
• Demonstrates avoidance during behavioral approach tests (defined as inability to put palm flat on the bottom of a tank containing a snake/spider, and inability to touch a snake/spider with a bare finger).

Exclusion criteria

• Unstable dose of psychotropic medications during the 4 weeks prior to baseline assessment.
• Currently receiving exposure-based treatment for snake/spider phobia.
• Currently at risk for suicide.