Effects of therapeutic relationship, expectancy, and credibility in breathing therapies for anxiety.

The authors investigated the effects of the quality of the therapeutic alliance, expectancy of improvement, and credibility of treatment on the outcome of two breathing therapies for anxiety and panic. Data were collected during a randomized clinical trial evaluating the efficacy of two theoretically opposing, end-tidal pCO2 feedback-assisted breathing therapies for patients experiencing anxiety attacks. In this study, five weekly individual breathing therapy sessions were administered for the patients who were experiencing anxiety attacks as symptoms of various anxiety disorders. The outcome of this trial indicated that regardless of the opposing breathing instructions (raise or lower pCO2) used in the two breathing therapies, patients in both treatment groups improved equally after treatment. Nonspecific factors rather than the different directions of pCO2 changes could have played a role in the improvement. Regression analyses showed that for both therapies patient-rated therapeutic alliance was predictive of improvement at the 1-month follow-up, and that patient-rated confidence that the therapy would produce improvement, an aspect of its credibility, accounted for almost half of the variance in improvement at the 6-month follow-up. Thus, two factors usually considered nonspecific were identified to be potent predictors of treatment outcome.