Listening to Prozac but Hearing Placebo: A Meta-Analysis of Antidepressant Medication

  title={Listening to Prozac but Hearing Placebo: A Meta-Analysis of Antidepressant Medication},
  author={Irving Kirsch and Guy Sapirstein},
  journal={Prevention \& Treatment},
Key MethodMean effect sizes for changes in depression were calculated for 2,318 patients who had been randomly assigned to either antidepressant medication or placebo in 19 double-blind clinical trials. As a proportion of the drug response, the placebo response was constant across different types of medication (75%), and the correlation between placebo effect and drug effect was .90. These data indicate that virtually all of the variation in drug effect size was due to the placebo characteristics of the…

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