Cláudia Carvalho
Assistant Professor, Instituto Superior de Psicologia Aplicada – Instituto Universitário

Open-label placebo treatment in chronic low back pain: A randomized controlled trial

We performed a randomized controlled trial designed to investigate whether placebo effects in chronic low back pain could be harnessed ethically by adding open-label placebo (OLP) treatment to treatment as usual (TAU) for 3 weeks. Pain severity was assessed on three 0- to 10-point Numeric Rating Scales, scoring maximum pain, minimum pain, and usual pain, and a composite, primary outcome, total pain score. Our other primary outcome was back-related dysfunction, assessed on the Roland–Morris Disability Questionnaire. In an exploratory follow-up, participants on TAU received placebo pills for 3 additional weeks. We randomized 97 adults reporting persistent low back pain for more than 3 months duration and diagnosed by a board-certified pain specialist. Eighty-three adults completed the trial. Compared to TAU, OLP elicited greater pain reduction on each of the three 0- to 10-point Numeric Rating Scales and on the 0- to 10-point composite pain scale (p < 0.001), with moderate to large effect sizes. Open label placebo treatment also reduced disability compared to TAU (p < 0.001), with a large effect size. Our findings suggest that OLP pills presented in a positive context may be helpful in chronic low back pain. Implications of the findings for the clinical practice are discussed.


Cláudia Ferreira de Carvalho, PhD, is a faculty member of ISPA-Instituto Universitário and a licensed clinical psychologist and psychotherapist  in private practice  in Lisbon, Portugal. Claudia received her graduation in Psychology from Oporto University, her MS on Clinical Psychology and Psychopathology from ISPA and her PhD in Health Psychology from Nova University of Lisbon. Her research and clinical interests include placebo effects, clinician-patient communication and empathy and how it affects health outcomes, hypnosis, and suggestibility. Claudia’s recent research focused on open-label placebo and its effect on chronic low back pain, research that has been featured in numerous magazine articles, including Nature, The New York Times and The Times.