JAMA Psychiatry
How powerful is the placebo effect across various mental disorders?
This systematic review and meta-analysis of 90 high-quality RCTs with 9,985 participants found significant improvement with placebo treatment for all 9 disorders, but the degree of improvement varied significantly among diagnoses. Patients with major depressive disorder experienced the greatest improvement, followed by those with generalized anxiety disorder, panic disorder, ADHD, PTSD, social phobia, mania, and OCD, while patients with schizophrenia benefited the least.
Study authors note that these findings may help in assessing the necessity and ethical justification of placebo controls.
- MEDLINE and the Cochrane Database were systematically searched in March 2022 for the latest systematic reviews meeting predetermined high-quality criteria for 9 major psychiatric diagnoses.
- A total of 90 RCTs with 9,985 placebo-treated participants were included.
- Symptom severity improved with placebo in all diagnoses.
- Pooled pre-post placebo effect sizes differed across diagnoses, with major depressive disorder and generalized anxiety disorder exhibiting the largest effect sizes, followed by panic disorder, ADHD, PTSD, social phobia, mania, OCD, and schizophrenia.
Source:
Bschor T, et al. (2024, May 29). JAMA Psychiatry. Differential Outcomes of Placebo Treatment Across 9 Psychiatric Disorders: A Systematic Review and Meta-Analysis. https://pubmed.ncbi.nlm.nih.gov/38809560/