“Across product characteristics, only higher THC levels were independently associated with greater symptom relief and prevalence of positive and negative side effects. In contrast, CBD potency levels were generally not associated with significant symptom changes or experienced side effects.”

https://www.ncbi.nlm.nih.gov/pubmed/30804402

https://www.nature.com/articles/s41598-019-39462-1

“Notorious psychoactive chemical THC more important for therapeutic effects in cannabis than previously believed. Contrary to popular media-reports and scientific dogma, the psychoactive chemical, tetrahydrocannabinol or “THC,” showed the strongest correlation with therapeutic relief and far less evidence for the benefits of relying on the more socially acceptable chemical, cannabidiol or “CBD.””  https://news.unm.edu/news/notorious-psychoactive-chemical-thc-more-important-for-therapeutic-effects-in-cannabis-than-previously-believed

“THC more important for therapeutic effects in cannabis than previously believed”  https://medicalxpress.com/news/2019-02-thc-important-therapeutic-effects-cannabis.html

“THC found more important for therapeutic effects in cannabis than originally thought” https://www.sciencedaily.com/releases/2019/02/190226112353.htm

“Study: Patients Find More Relief In Marijuana‘s Physchoactive Compound THC Than In CBD.” https://www.forbes.com/sites/javierhasse/2019/02/27/study-patients-find-more-relief-in-marijuanas-physchoactive-compound-thc-than-in-cbd/#384ee158717a