Reviewed by Emily Henderson, B.Sc.May 30 2020

Harm reduction strategies have proven effective for use of opioids, alcohol, and tobacco products.

University at Buffalo and University of Michigan researchers say harm reduction techniques also have the potential for cannabis users – but first, public health practitioners and organizations need to do a better job of making cannabis users aware of those strategies.

Researchers assessed harm reduction awareness by surveying nearly 500 participants at the 2019 Hash Bash, a popular marijuana advocacy event on the campus of the University of Michigan.

The research team has published a series of papers in recent years based on data collected by surveying Hash Bash attendees.

Their latest study, published in Health Promotion Practice, shows that frequent cannabis users aren’t as knowledgeable as they should be about harm reduction strategies, such as not driving within six hours of using cannabis.

And that, the researchers argue, falls more squarely on public health’s failure to properly provide that knowledge.

“Our findings should serve as a wake-up call to public health professionals to integrate harm reduction strategies into practice,” said Jessica Kruger, Ph.D., the study’s lead author and a clinical assistant professor of community health and health behavior in UB’s School of Public Health and Health Professions.

As more states legalize medicinal and recreational use of cannabis, it’s important that public health equip people with proper knowledge about using cannabis. We know that abstinence just isn’t realistic or desirable for some users. We can minimize the costs and risks of cannabis use by creating awareness around harm reduction strategies.”

Jessica Kruger Ph.D, Study Lead Author and Clinical Assistant Professor, Community Health and Health Behavior, University at Buffalo

Fewer than half of the study participants believed that any of the listed strategies reduced the harm of using cannabis. Only 42% identified avoiding use when pregnant as an effective harm reduction strategy. Even less, 36%, identified avoiding driving within six hours of using cannabis as an effective strategy.

“This is really remarkable, given that both of these are common warnings for a variety of psychoactive and pharmaceutical substances,” said co-author Daniel Kruger, Ph.D., a research associate professor of community health and health behavior in UB’s School of Public Health and Health Professions.

He is also a research investigator with the Population Studies Center at the University of Michigan.

About one-quarter of participants believed that using strains with high cannabidiol (CBD) CBD to tetrahydrocannabinol (THC) ratios, using a concentrate or dab without plant material, and putting ice in a bong to reduce cannabis potency were effective harm reduction techniques.

Only using strains with a high CBD to THC ratio has been empirically supported, the researchers note.

Less than half of participants reported using any harm reduction strategy, and 39% reported using no effective strategy.

Although knowledge doesn’t guarantee behavior or behavior change, the researchers note that providing cannabis users with accurate information on the risks and benefits of the drug will at least help users make informed decisions.

They point to two public health campaigns in Colorado, a state where cannabis is legal for adult use. That state’s “Good to Know” campaign educated Colorado residents on new cannabis laws.

The state’s “Responsibility Grows Here” campaign shares information about the potential risks for teens and pregnant and breastfeeding women, and calls on users to consume cannabis responsibly.

“As more and more people have legal access to medical and recreational cannabis, the importance of effective cannabis-specific health education increases,” said study co-author R. Lorraine Collins, Ph.D., associate dean for research in UB’s School of Public Health and Health Professions and a professor of community health and health behavior.