The results have been decidedly mixed.

But now state-funded researchers have launched a new campaign, backed by what they hope will be two secret ingredients: mountains of science and hours spent around the state listening.

The campaign is called The Tea on THC, and its roots stretch back to 2021, when the Colorado Legislature tasked the Colorado School of Public Health with studying the effects of high-potency cannabis. The first phase of that process — a lengthy review of hundreds of studies on the subject — produced a 2023 report that summarized the findings to that point. A complex data dashboard continues to add new studies to the analysis.

The Tea on THC represents the second phase of this research project: Turning the data into effective public health messages. The campaign especially focuses on messages that caution about potential negative mental health consequences from using high-THC marijuana.

“This campaign lays out what we know and what we don’t to help the public make the best-informed decisions possible,” Dr. Jonathan Samet, the former dean of the Colorado School of Public Health, who worked on the project, said this month during a campaign kickoff event. “Importantly, it encourages people to talk to each other openly and respectfully about cannabis use.”

SCIENCE AND POT

Samet’s acknowledgment of the unknowns is appropriate because there is still much to be learned.

It’s been barely a decade since Colorado’s first recreational pot shops opened — the first in the country. Since then, the cannabis industry both locally and nationally has undergone rapid transformation, developing and introducing both higher-potency marijuana buds but also concentrates and edible products that, combined, now make up nearly half of the market.

This kind of accelerated evolution makes it difficult for careful, time-consuming science to catch up — especially because the federal prohibition of marijuana meant that, until recently, a lot of research pot came from a single source notorious for producing low-quality cannabis.

“Today’s marketplace, the science lags what’s in it,” Samet said.

When the School of Public Health released the report on its findings last year, researchers concluded there was at best only limited evidence to support many of the potential effects of consuming high-THC cannabis, either good or bad. That includes questions like whether high-THC cannabis helps with pain or sleep or whether it worsens intellectual functioning.

THE RISKS

The area of concern with the strongest evidence had to do with mental health. Researchers concluded there is moderate evidence that frequent use of high-THC cannabis can lead to worse mental health and psychosis, especially among those who are already at-risk.

Studies subsequently added to the analysis strengthened that concern, said Greg Tung, one of the School of Public Health researchers who worked on the review.

“That’s one of the strongest areas,” he said. “Specifically within that broad umbrella, psychosis and psychotic disorders is one of the negative outcomes that has started to emerge with studies consistently showing an association between high-concentration product use, greater frequency, earlier initiation and psychotic disorders.”

Given this evidence — even if it is still somewhat murky — the research team decided it needed to move forward with a public health campaign focused on educating teens, as well as pregnant women and new mothers, on the risks of using high-THC cannabis.

“We’re not here for a definitive answer just yet, but doing nothing isn’t an option,” Cathy Bradley, the School of Public Health’s current dean, said. “We have to inform. We have to use the best evidence we have and go forward.”

But, as Colorado’s history with cannabis PSAs shows, deciding how to do them is the bigger challenge.

STONER HUMOR FAILED

In 2014, shortly after the first recreational cannabis shops opened in Colorado, state officials tried their hand at a public health messaging campaign aimed at encouraging responsible use of the drug.

They went with stoner humor.

In commercials showing befuddled cannabis users trying to light grills not connected to propane or trying to watch televisions they had neglected to secure to the wall, the state sought a new way to talk to the public about the potential harms of a newly legal substance. (The campaign specifically tried to prevent drugged driving.) But the ads were criticized for being condescending.

Next came a high-concept messaging campaign targeted at teens that featured human-scale rat cages installed across Denver as a way of warning about the dangers of marijuana use for a developing brain. (Campaign name: Don’t be a lab rat.) Those were promptly vandalized and ridiculed — so much so that at least one city balked at installing one.

Then came another 180 — a campaign featuring hoedown music where listeners were told cannabis PSAs by a guy speaking in a folksy, rhyming twang. (That one may have actually worked.)

Colorado’s struggles are hardly unique. Public health campaigns around drugs are notoriously difficult to do well. Done poorly, they can backfire.

All of this is to say that the team from the School of Public Health had its work cut out for it in designing an ad campaign that people would actually take seriously.

Enter: A Denver health care consulting firm and a former Denver Bronco.

STRONG MESSAGE

Brandon Lloyd played 11 seasons as a wide receiver in the National Football League, including parts of three seasons in Denver, during one of which he led the league in receiving yards.

During much of his career, he said he used cannabis to cope with the stress and pressures of playing in the spotlight. His cannabis use continued into his post-playing career, when the loss of that fame led to new emotional challenges.

Lloyd said he stopped using cannabis about four years ago as he embraced a life filled with vigorous exercise, connection with friends and self care.

“All those tropes about marijuana not being addictive were just so false,” Lloyd says in a video recorded for The Tea on THC campaign. “The high-concentration marijuana was incredibly addictive.”

Llyod’s story shows one way that the campaign approaches its messaging — in addition to claims backed by studies, the campaign also wants to use personal experiences to drive home the concerns around high-THC cannabis.

The campaign also features videos of teens talking about their experiences with marijuana, as well as a mother whose son died by suicide after developing psychosis.

“It’s not another hot take on the cannabis industry,” Lloyd said at the campaign kickoff event. “We are actually a group of individuals who are sharing our stories, and we know that we’re not alone.”

AVOIDING PROPAGANDA

The campaign’s messages also came about after many hours of listening to teens and adults talk about what kind of words and warnings resonated with them.

To create the campaign, the Colorado School of Public Health worked with a consulting company called Initium Health. James Corbett, the firm’s leader, said these listening sessions helped the campaign dial in its message to different audiences.

This was especially true for teens, who were wary of what they viewed as propaganda and wanted the autonomy to make up their own minds. Hence the campaign’s rather bland tagline: “Get the facts.”

“Most of the things I thought would work, they told me the opposite,” Corbett said. “As soon as I start saying ‘Don’t,’ that’s a problem. As soon as I start using even ‘Know the risk,’ some of our testing said for youth it had to be just the facts, not even ‘Know the risk.’

“Conversely, with moms, our data said that ‘Know the risk’ meant more.”

As a result, a poster targeted at nursing mothers specifically uses the phrase “Know the risks,” while the posters targeted at teens do not.

Corbett said the campaign will continue to do follow-up research to see if its message is landing or whether it needs to be tweaked.

The campaign may also expand to focus on other audiences, such as older Coloradans. Or it could take on a regional component, with messages dialed into specific parts of the state.

Bradley, the School of Public Health dean, said it is important for this campaign to push forward and find success in how it communicates about cannabis.

“We’re asking the questions that must be asked,” she said, “and starting conversations that are long overdue.”