Experts call for look at public health implications of medical marijuana

In this Feb. 14, 2018, file photo, marijuana plants are displayed at a dispensary in Berkeley, Calif.

A bill attempting to legalize medical cannabis in Tennessee gained more support this year than previous years' legislation before ultimately dying, which is why Dr. Michael Warren says it's time to seriously discuss marijuana's potential public health implications.

"We've been looking at this for the last four to five years and fully anticipate that this is going to be back in the future," said Warren, deputy commissioner for population health at the Tennessee Department of Health, who spoke Wednesday at the Chattanooga Clear the Air Conference.

Currently, 30 states and the District of Columbia allow comprehensive medical marijuana and cannabis programs, according to the National Conference of State Legislatures.

In 2017, Georgia Gov. Nathan Deal signed a law expanding the state's medical marijuana program, which began in 2015, to cover six more conditions, including autism, epilepsy and Parkinson's disease.

Tennessee's initial bill created a detailed program through which eligible patients could access limited quantities of cannabis ointment, lotion, transdermal patches, suppositories, nasal spray, tincture, oil or capsules through dispensaries.

But when the original 72-page bill started losing traction, it was reduced to four pages that focused on decriminalizing possession.

Warren said once the bill changed, backing from marijuana lobbyists wavered, leading some to suspect their main goal was to support a money-making industry rather than medicine.

"It makes me wonder, as a health advocate, are we really pushing for something from a health perspective, or are we following in the footsteps of big tobacco?" he said.

As lawmakers across the country forge ahead, many public health leaders are "trying to wrap their heads around what this means for health outcomes," Warren said.

Dr. Elinore McCance-Katz, who directs the federal Substance Abuse and Mental Health Services Administration, recently expressed concern at the National Council for Behavioral Health's annual conference and in a tweet on April 20, the unofficial holiday that celebrates cannabis.

"We need to protect our children from the adverse effects of #marijuana use," she tweeted.

Some public health fears include youth initiation, use during pregnancy, accidental ingestion, motor vehicle collisions caused by impaired drivers and possible effects on disadvantaged populations. And while our understanding of medical marijuana is growing, there remain too many unknowns, Warren said.

"Getting that research funded, actually doing the research, then writing it up, takes time," he said. "I think sometimes there's a hesitancy to be patient with hearing that, but we really need that information to be able to make those good decisions."

He outlined the state department's stance, which supports ongoing, quality research, but highlights three areas where popular opinions - such as marijuana being harmless - often don't align with current literature: the individual benefits of marijuana have been overstated, population harms have been underestimated and marijuana is not a solution to the opioid crisis.

So far, the bills presented in Tennessee require providers to certify patients with qualifying medical conditions - such as cancer, HIV, multiple sclerosis, post-traumatic stress disorder, sickle-cell anemia or hepatitis - to purchase medical marijuana, but don't require a prescription for the substance.

"There really aren't any rules that we have, other than [for the two FDA approved forms], to know how folks could use this or should use this and how we might recommend it," Warren said.

Without a prescription, providers and patients are left guessing when it comes to type, dosing and quantity, which is another concern.

"If you think of us as lobbyists or advocates for health, we're going to be right there saying, 'We need to make decisions based on science. We have to think about the health of the entire population," he said. "That's what we do in public health."

Contact staff writer Elizabeth Fite at or 423-757-6673.