Extinction Generalization in Exposure Therapy

Patients with anxiety disorders oftentimes express fear responses to more than only one fear-inducing object. The principal aim of this study is to examine whether the beneficial effects of exposure on fear reduction in spider phobia can extend to stimuli which are conceptually similar to spiders (i.e. cockroaches), but have never been presented during the respective treatment.

Fear extinction has evolved as the central mechanism underlying exposure-based treatments. Findings from conditioning studies indicate that fear reduction following a fear extinction procedure can generalize from the extinction stimulus to other conceptually and perceptually related stimuli. This study is aimed at translating these findings to a clinical application and will hence examine whether the basic principles of extinction generalization are applicable to exposure. Patients with spider phobia will either receive two sessions of in-vivo exposure with spiders or no treatment. Prior to as well as after treatment, patient's fear of spiders will be assessed using the Behavioral Approach Test (BATs) and self-report questionnaires. In addition, BATs with cockroaches will be conducted to examine the effects of exposure therapy on extinction generalization.

Two sessions (each session = 60 minutes) of in-vivo exposure treatment (including psychoeducation) with two different spiders. Exposures comprise a hierarchy of 7 steps, to be completed with both spiders.

Behavioral Approach Tests with Spiders and Cockroaches will be conducted at pre- and posttreatment. Here, the closest proximity a participant is able to attain to the spider/cockroach will be measured.

Change in Subjective Fear / Disgust during the Behavioral Approach Tests (BATs) using the Subjective Units of Distress Scale (SUDS)

Subjective Fear / Disgust during the Behavioral Approach will be assessed at the initial and final approach distances to the spider / cockroach during the respective BATs.

During each BAT with spiders and cockroaches, heart rate will be measured. In addition, a 5-minute baseline will be recorded prior to the first BAT at each assessment.

Inclusion Criteria: spider phobia according to Diagnostic and Statistical Manual of Mental Disorders (DSM) -IV criteria Exclusion Criteria: any neurological or neuropsychiatric condition current behavioral or pharmacological treatment any mental disorder that is considered more severe than specific phobia