Correlates of placebo response in the treatment of sexual dysfunction in women: a preliminary report.

Introduction: Placebo responses have been large across a number of clinical trials for treatment of women's sexual dysfunction. Studying placebo responses may elucidate predictors of symptom reduction and responsiveness to intervention.

Aim: To determine the correlates of placebo response in participants enrolled in a clinical trial for female sexual dysfunction.

Methods: We analyzed data from 16 women with sexual arousal and orgasmic dysfunction who were randomized to receive 8 weeks of placebo treatment within a larger randomized controlled trial. Using nonparametric correlations, we tested whether age, length of relationship, psychological symptoms, and scores on self-report measures predicted change in sexual function with placebo treatment.

Main Outcome Measure: Female Sexual Function Index.

Results: Consistent with findings from other studies, we found a significant improvement in sexual function scores after 8 weeks of treatment with placebo. We also found that age and length of relationship predicted the magnitude of change in sexual function across treatment. Changes in relationship adjustment, but not relationship adjustment at baseline, predicted the magnitude of improvement in sexual function scores. We observed no relationship between psychological symptom severity and change in sexual function.

Conclusions: Participant age and length of relationship predicted subsequent magnitude of change in sexual function scores during treatment with placebo. In addition, relationship adjustment covaried with changes in sexual function. Our findings suggest that "placebo effects" may represent underlying factors that influence the way in which women respond to the process of treatment.