The influence of therapeutic expectancy/demand on self-efficacy ratings

If expectancy/demand manipulations influence self-efficacy ratings independent of therapy effects or if outcome effects can be shown to be independent of efficacy ratings, questions would be raised about the mediational role of self-efficacy in the change process. Speech-anxious subjects underwent a single session of repeated in vivo exposure versus imaginal placebo under neutral versus positive therapeutic instructions in an effort to separate the effects of expectancy/demand and active therapy ingredients. Efficacy ratings and self-reported outcome were found to be significantly influenced by the expectancy manipulation, whereas no behavioral measures were influenced and heart rate outcome was due to an expectancy by treatment interaction. Canonical correlation analyses revealed significant associations between changes in efficacy ratings and self-reported anxiety but no relationships to behavioral and physiological measures. Although therapy did not have a separate main effect, precluding unambiguous conclusions regarding efficacy's mediational role, the possible influence of therapeutic expectancy on efficacy ratings was documented.