Effect of combined multiple contexts and multiple stimuli exposure in spider phobia: A randomized clinical trial in virtual reality.
BACKGROUND
Our previous study indicated that treatment in multiple contexts (MC) improved the outcome of exposure treatment by reducing return of fear. This effect was evident when the test was conducted immediately post treatment. In the present study, we conducted a treatment analogue study where we investigated whether an exposure to multiple stimuli (MS) and a combination of both MS and MC would further improve treatment efficacy in the short and long terms.


METHOD
Spider-phobic patients (N = 58) were randomly allocated to one of four groups. Each group received virtual reality (VR) exposure treatment in either one or four different contexts and was exposed to either one or four different spiders. All participants completed both a VR test with a novel spider in a novel context and an in vivo behavioral avoidance test (BAT) pre-, post-treatment and at follow-up.


RESULTS
Short-term but not long-term return of fear was attenuated by multiple context exposure in VR. Long-term effect of fear attenuation was observed only in the MS single context group. In the BAT, the multiple stimuli condition seemed to be more beneficial in both the short and long term. Notably, there was no evidence for superiority of the combined multiple stimuli and contexts condition.


CONCLUSION
Change of contexts during exposure significantly reduced return of fear post treatment; however, similar results could not be observed with a follow-up test. The implementation of multiple stimuli during exposure seems to have both short-term and long-lasting beneficial effects on the treatment outcome. We recommend further investigation of this phenomenon and introduce further possible improvements to our paradigm.