Why do open-label placebos work? A randomized controlled trial of an open-label placebo induction with and without extended information about the placebo effect in allergic rhinitis

摘要

BackgroundSeveral studies demonstrated that placebo treatment may have a significant impact on many different symptoms. While in the traditional view concealment of the placebo is essential, recent studies report intriguing evidence that placebos may work even without deception. For example, it has been demonstrated that open-label placebos can improve symptoms in allergic rhinitis. However, the mechanisms of how placebos without concealment work remain unknown.