By Pat Anson, PNN Editor

The psychoactive ingredient in marijuana -- tetrahydrocannabinol (THC) – is more effective than cannabidiol (CBD) in treating chronic pain and other medical conditions, according to a new study that challenges the widespread belief that THC is harmful and has limited value in medical cannabis products.

Researchers at the University of New Mexico used the Releaf App, a mobile software program, to analyze self-reported data from over 3,300 people who logged their responses in nearly 20,000 user sessions to a variety of cannabis products, including natural dried flower, edibles, tinctures and ointments.

Dried flower was the most commonly used product and was generally associated with greater pain relief than other cannabis products, regardless of the amount of THC.

"Despite the conventional wisdom, both in the popular press and much of the scientific community that only CBD has medical benefits while THC merely makes one high, our results suggest that THC may be more important than CBD in generating therapeutic benefits,” said Jacob Miguel Vigil, PhD, a professor in UNM’s Department of Psychology.

“In our study, CBD appears to have little effect at all, while THC generates measurable improvements in symptom relief. These findings justify the immediate de-scheduling of all types of cannabis, in addition to hemp, so that cannabis with THC can be more widely accessible for pharmaceutical use by the general public.”

Hemp is a strain of marijuana that was legalized by Congress in the 2018 Farm Bill. It has very low levels of THC, but is being grown commercially as a source for CBD.

UNM researchers found that indica strains of cannabis were more effective than sativa strains in treating pain and insomnia. Both strains have substantially higher levels of THC than hemp, but are illegal Schedule I controlled substances under federal law.

“Only THC potency levels showed independent associations with symptom relief and experiences of both positive and negative side effects, with higher levels (of THC) resulting in larger effects,” Vigil said.

Researchers say the relative weakness of CBD in treating symptoms may be due to inaccurate labeling of CBD content in cannabis products, which is a widespread industry problem. It’s also possible that THC simply heightens the experience or awareness of symptom relief.

Vigil published his findings in the journal Scientific Reports. Three of his co-authors developed the Releaf App, which has collected information from cannabis users since 2016. The app is an important data source for researchers, who are currently limited in conducting clinical studies of cannabis because of federal regulations.

Two previous studies by Vigil using data from the Releaf App found that cannabis provides significant relief from a wide range of symptoms associated with chronic pain, including insomnia, seizures, depression, anxiety and fatigue.