Anti-phobic and Safety Behaviors in the Treatment of Acrophobia

This study tests whether a single session of exposure therapy may be enhanced by the addition
of one of two augmentation strategies, including engagement in anti-phobic actions and fading
of safety behaviors. Because utilization of safety behaviors is functionally precluded by
anti-phobic action, the present study design will both replicate and extend prior research by
addressing whether anti-phobic actions enhance exposure therapy beyond the mere fading of
safety behaviors. A total of 100 individuals between the ages of 18 and 65 meeting DSM-IV
criteria for acrophobia (fear of heights) will be randomly assigned to one of four conditions
including (1) standard exposure therapy, (2) exposure therapy with safety behavior fading,
(3) exposure therapy with safety behavior fading and anti-phobic actions, and (4) a wait-list
control condition. All participants will complete an online prescreen and face-to-face
screening assessment to determine eligibility and pre-treatment symptom severity.
Participants will also complete assessments at post-treatment and 1-month follow-up
assessments. Subjective fear during two behavioral approach tests (in the treatment and
generalization context, respectively) conducted at pre-treatment, post-treatment, and 1-month
follow-up assessments will serve as the primary measure of treatment outcome. Additionally, a
battery of self-report questionnaires will be completed at pre-treatment, during treatment,
at post-treatment, and at a 1-month follow-up assessment.

Inclusion Criteria:

1. Age 18 to 65.

2. Fluent in English (written and spoken). This is required because assessment
instruments are validated only in English.

3. Meet DSM-IV criteria for specific phobia, natural environment type, with acrophobic
concerns, based on the Composite International Diagnostic Interview (CIDI-Auto; World
Health Organization, 1997).

4. Report moderate fear or avoidance (i.e., a score of 30 or higher) on a modified
version of the Acrophobia Questionnaire (AQ; Cohen, 1977).

5. Exhibit at least moderate fear (i.e., a fear score of 50 or higher, where 0 = no fear
and 100 = extreme fear) during two behavioral approach tests (BATs) consisting of
ascending two moderately challenging flights of stairs.

Exclusion Criteria:

1. Medical condition(s) which may prevent safely climbing or descending stairs or walking
for more than 15 minutes at a time (It will be necessary to walk to different sites for the
behavioral approach tests).