Use of Safety Behaviors in Exposure Therapy for Arachnophobia

This study examines the impact of safety behaviors (i.e., unnecessary protective actions) on outcomes of exposure therapy for spider phobia. Researchers will compare exposure therapy with (a) no safety behaviors, (b) safety behaviors faded toward the end of treatment, and (c) unfaded safety behaviors.

Some studies suggest that safety behaviors might undermine the efficacy of exposure therapy (Powers et al., 2010), whereas other studies suggest that there is no difference in exposure therapy outcomes whether or not safety behaviors are used (Deacon et al., 2010). Mixed findings could be explained by the parameters of safety behaviors use, such as whether they are used throughout the full course of therapy or faded toward the end of therapy. This will be the first study to directly compare the impact of faded and unfaded safety behaviors on exposure therapy outcomes. Specifically, researchers will randomize participants with a fear of spiders to receive exposure therapy (a) without safety behavior use, (b) with faded safety behavior use, and (c) with un-faded safety behavior use. Researchers will compare each condition's impact on fear reduction and on the tolerability/acceptability of treatment.

Exposure therapy will involve three, 10-minute trials in which participants encounter a spider. Participants in this group will wear protective gear during the first two trials, and will remove the protective gear during the last trial.

Exposure therapy will involve three, 10-minute trials in which participants encounter a spider. Participants in this group will not wear protective gear during any of the exposure therapy trials.

Exposure therapy will involve three, 10-minute trials in which participants encounter a spider. Participants in this group will wear protective gear during all three exposure therapy trials.

Exposure therapy will involve three, 10-minute trials in which participants encounter a spider. Participants in this group will wear protective gear during the first two trials, and will remove the protective gear during the last trial.

Exposure therapy will involve three, 10-minute trials in which participants encounter a spider. Participants in this group will not wear protective gear during any of the exposure therapy trials.

Exposure therapy will involve three, 10-minute trials in which participants encounter a spider. Participants in this group will wear protective gear during all three exposure therapy trials.

Participants will approach a live, non-poisonous tarantula, placed on the floor, at the opposite end of the room. The participant will walk toward the spider during this test. The test is over when the participant has reached the hardest step that they can complete at that time. During this BAT, investigators will assess fear response behaviorally by recording the most challenging step completed (range, steps 0 -12).

Participants will approach a live, non-poisonous tarantula, placed on the floor, at the opposite end of the room. The participant will walk toward the spider during this test. The test is over when the participant has reached the hardest step that they can complete at that time. During this BAT, investigators will assess fear response subjectively by having participants self report their peak fear level (on a 0 to 100 scale).

Participants will approach a live, non-poisonous tarantula, placed on the floor, at the opposite end of the room. The participant will walk toward the spider during this test. The test is over when the participant has reached the hardest step that they can complete at that time. During this BAT, investigators will assess fear response physiologically by assessing heart rate variability.

Participants will approach a live, non-poisonous tarantula, placed in a clear tank on a table, at the opposite end of the room. The test is over when the participant has reached the hardest step that they can complete at that time. Steps include walking toward the spider and lowering one hand into the tank. During this BAT, investigators will assess fear response behaviorally by recording the most challenging step completed (range, steps 0-21).

Participants will approach a live, non-poisonous tarantula, placed in a clear tank on a table, at the opposite end of the room. The test is over when the participant has reached the hardest step that they can complete at that time. Steps include walking toward the spider and lowering one hand into the tank. During this BAT, investigators will assess fear response subjectively by having participants self report their peak fear level (on a 0 to 100 scale).

Participants will approach a live, non-poisonous tarantula, placed in a clear tank on a table, at the opposite end of the room. The test is over when the participant has reached the hardest step that they can complete at that time. Steps include walking toward the spider and lowering one hand into the tank. During this BAT, investigators will assess fear response physiologically by assessing heart rate variability.

Self-report rating scale in which participants rate the extent that they agree with a number of statements that are representative of having a fear of spiders. Sum total scores will be calculated (range 0-108). Higher scores indicate more severe symptom levels.

Self-report rating scale assessing the level to which the participant believes a number of cognitions/thoughts commonly associated with spider phobia. An overall average rating will be calculated (range 0-100). Higher average scores indicate greater belief in spider phobic cognitions.

Self-report questionnaire assessing feelings of disgust associated with spiders. Sum total scores will be calculated (range 0-48). Higher scores indicate more severe spider-related disgust.

Participants will be given a structured interview to identify whether they meet diagnostic criteria for specific phobia. Responses will be coded dichotomously (yes = has diagnosis; no = no diagnosis).

Self-report questionnaire assessing the participant's perceptions regarding treatment acceptability and willingness to adhere to treatment procedures. Sum total scores will be calculated (range 10-70). Higher scores indicate greater acceptability/adherence.

Self-report questionnaire assessing the participant's perceptions regarding treatment acceptability and willingness to adhere to treatment procedures. Sum total scores will be calculated (range 10-70). Higher scores indicate greater acceptability/adherence.

Inclusion Criteria: Fluent in English Displays sufficiently high fear of spiders, as indicated by responses on (a) a self report questionnaire (the Fear of Spiders Questionnaire) at prescreening, and (b) Behavioral Avoidance Tests at baseline Exclusion Criteria: younger than 18 years old

Powers MB, Smits JA, Telch MJ. Disentangling the effects of safety-behavior utilization and safety-behavior availability during exposure-based treatment: a placebo-controlled trial. J Consult Clin Psychol. 2004 Jun;72(3):448-54. doi: 10.1037/0022-006X.72.3.448.

Deacon BJ, Sy JT, Lickel JJ, Nelson EA. Does the judicious use of safety behaviors improve the efficacy and acceptability of exposure therapy for claustrophobic fear? J Behav Ther Exp Psychiatry. 2010 Mar;41(1):71-80. doi: 10.1016/j.jbtep.2009.10.004. Epub 2009 Oct 24.