"The data from the present meta-analysis, including 1459 patients with clinical pain, suggest that placebo responses contribute significantly to the pain reduction seen in cannabinoid randomized clinical trials," the investigators led by Filip Gedin, PhD, a post-doctoral fellow at the Karolinska Institute in Solna, Sweden, write.

The researchers speculate that the sheer amount of media attention surrounding cannabis trials may have contributed to a strong positive bias toward the efficacy of cannabinoids in pain therapy.

The findings were published online November 28 in the JAMA Network Open.

https://www.medscape.com/viewarticle/985360

This outcome is something I have long thought to be true based upon my experiences with patients who try CBD products for everything from pain relief to sleeping issues. The initial reaction is positive for many but the effects are sustainable. This has led me to the same consensus as the study points out; high and positive expectation driven by media causing placebo effect.