Psychotherapy credibility ratings: patient predictors of credibility and the relation of credibility to therapy outcome.

Objective: The current investigation examined the relation between credibility ratings for adult psychotherapies and a variety of patient factors as well as the relation between credibility ratings and subsequent symptom change.

Method: A pooled study database that included studies evaluating the efficacy of cognitive and psychodynamic therapies for a variety of disorders was used. For all studies, a three-item credibility scale was administered at session 2. Patient variables at baseline were used to predict early treatment credibility.

Results: Early symptom improvement, age, education, and expectation of improvement were all significantly predictive of credibility scores at session 2. In one combined multiple regression model controlling for treatment, study, and early symptom change, age, education, and expectation of improvement remained significantly predictive of credibility scores. Credibility was predictive of subsequent symptom change even when controlling for age, education, expectation of improvement, and early symptom improvement.

Conclusions: These findings suggest that age and education, in addition to expectations of improvement and the amount of early symptom improvement, may influence the patient's perceptions of the credibility of a treatment rationale early in the treatment process and that credibility ratings predict subsequent symptom change.