"We did this study because we wanted to understand the reasons why people are using cannabis medically and whether those reasons for use are evidence-based", Kevin Boehnke, a research investigator in the department of anesthesiology and the Chronic Pain and Fatigue Research Center, said in a news release. Researchers compared the symptoms and conditions with a comprehensive review of the scientific evidence: a 2017 report from the National Academies of Sciences, Engineering and Medicine.
That's followed by stiffness from multiple sclerosis and chemotherapy-related nausea, according to an analysis of 15 states published Monday in the journal Health Affairs. But the patients' reasons match up with what's known about the science of marijuana and its chemical components.
As of 2018, 33 states and the District of Columbia have approved the medical use of cannabis, while 10 states have legalized marijuana for recreational use. However, those qualifying conditions vary by state law. The report found that 85.5% of patient-reported qualifying conditions (chronic pain, nausea, and vomiting stemming from chemotherapy, as well as multiple sclerosis spasticity symptoms) were backed up by either conclusive or substantial evidence of marijuana's effectiveness for those conditions, the University of MI researchers reported. However, it should be noted that people could select multiple different kinds of pain, so you shouldn't assume two-thirds of medical marijuana patients do so for chronic pain.
Researchers said it was not surprising that chronic pain was by far the most prevalent qualifying condition for use of medical marijuana, given that 100 million Americans experience chronic pain.
The study did highlight one problem: The many inconsistencies in data quality among the states that have legalized marijuana.
The study included data on medical cannabis license holders in 20 states.
Patients include 37-year-old Brandian Smith of Pana, Illinois, who qualifies because she has fibromyalgia.
She told the Associated Press that on bad days, her muscles feel like they're being squeezed in a vise. She said she has stopped taking opioid painkillers because marijuana works better for her. The findings might surprise some critics who believe most people go to dispensaries to procure marijuana for recreational use.
The U.S. National Institute on Drug Abuse has more about medical marijuana.
The researchers argued that it is time for the federal government to change its classification of marijuana as a Schedule 1 drug under the Controlled Substances Act, which defines it as a drug with no now accepted medical use and a high potential for abuse.
This study provides support for legitimate evidence-based use of medical marijuana that challenges its current federal drug status, Boehnke said.
"Since the majority of states in the USA have legalized medical cannabis, we should consider how best to adequately regulate cannabis and safely incorporate cannabis into medical practice", Boehnke said.