Placebo effects in spider phobia: an eye-tracking experiment.

Several eye-tracking studies have revealed that spider phobic patients show a typical hypervigilance-avoidance pattern when confronted with images of spiders. The present experiment investigated if this pattern can be changed via placebo treatment. We conducted an eye-tracking experiment with 37 women with spider phobia. They looked at picture pairs (a spider paired with a neutral picture) for 7 s each in a retest design: once with and once without a placebo pill presented along with the verbal suggestion that it can reduce phobic symptoms. The placebo was labelled as Propranolol, a beta-blocker that has been successfully used to treat spider phobia. In the placebo condition, both the fixation count and the dwell time on the spider pictures increased, especially in the second half of the presentation time. This was associated with a slight decrease in self-reported symptom severity. In summary, we were able to show that a placebo was able to positively influence visual avoidance in spider phobia. This effect might help to overcome apprehension about engaging in exposure therapy, which is present in many phobic patients.