Induction of Efficacy Expectancies in an Ambulatory Smartphone-Based Digital Placebo Mental Health Intervention: Randomized Controlled Trial

Esther Stalujanis   ^{1, 2} , MSc ;   Joel Neufeld   ³ , MSc ;   Martina Glaus Stalder   ³ , MSc ;   Angelo Belardi   ¹ , PhD ;   Marion Tegethoff   ^{1, 4} , PhD ;   Gunther Meinlschmidt   ^{2, 3, 5} , PhD

¹ Division of Clinical Psychology and Psychiatry, Department of Psychology, University of Basel, Basel, Switzerland

² Department of Clinical Psychology and Cognitive Behavioral Therapy, International Psychoanalytic University Berlin, Berlin, Germany

³ Division of Clinical Psychology and Epidemiology, Department of Psychology, University of Basel, Basel, Switzerland

⁴ Institute of Psychology, RWTH Aachen, Aachen, Germany

⁵ Department of Psychosomatic Medicine, University Hospital Basel and University of Basel, Basel, Switzerland