Nearly half of adults in the United States who use cannabis mainly smoke it, but about 1 in 7 use it in nearly every form available, a behavior tied to daily cannabis use and increased addiction risk, a new study shows.
Cannabis can be consumed through smoking, vaping, eating, or dabbing, a practice in which people heat cannabis concentrates and inhale the vapor. According to recent national survey data, about 43.8 million people in the US ages 12 and older (more than 15 percent) had used cannabis in the past 30 days.
Led by NYU Langone Health researchers, the study showed that 48 percent mainly smoked, 21 percent both smoked and vaped, 17 percent mainly used edibles, and 14 percent, the "polymodal group," used cannabis in nearly every form.
Published online August 8 in the journal Addictive Behaviors, the work showed that about half of the polymodal group used cannabis every day. By comparison, 28 percent of those who mostly smoked, 31 percent of those who smoked and vaped, and about 13 percent of those who mostly ate edibles used cannabis every day. Cannabis use disorder, the clinical term for related addiction, followed the same pattern, affecting about 67 percent of polymodal users versus 36 percent of those who primarily smoked, 47 percent of those who smoked and vaped, and 15 percent of those who mainly consumed edibles.
"Our findings suggest that using cannabis in multiple forms may be a red flag for heavier use and symptoms of addiction," said study lead author Omar El-Shahawy, MD, PhD, MPH, an assistant professor in the Department of Population Health at NYU Grossman School of Medicine. "Asking patients not only whether but how they use cannabis could help clinicians identify when a fuller assessment may be warranted."
In the first national study to examine how these methods naturally cluster, the researchers analyzed data from 17,732 adults who reported using cannabis in the past month on the 2022–2023 National Survey on Drug Use and Health. The authors used a statistical approach that grouped participants based on their reported patterns.
The results also revealed that types of cannabis users varied demographically. Nearly 1 in 3 people in the smoking-and-vaping and polymodal groups were young adults ages 18 to 25, compared with about 1 in 6 of those who mainly smoked. More than half of the edibles group were women, and edibles were especially prevalent among college graduates. Since the researchers did not examine why participants chose particular methods of cannabis use, the reason behind these patterns remains uncertain, said Dr. El-Shahawy.
Another key finding was that people who smoked cannabis were more likely to also smoke cigarettes, compared with those who mainly vaped or used edibles. Both cigarette and cannabis smoke involve combustion (burning), which can be hard on the lungs, so doing both may add to their overall health risks.
"The strong tie between smoking cannabis and smoking cigarettes is of concern because this subset of people are breathing in a wider range of chemicals via combustion, and their lungs are at risk," said senior author Joseph J. Palamar, PhD, MPH, a professor in the Department of Population Health at NYU Grossman School of Medicine.
"Public health messages about cannabis still focus mostly on smoking, but people now use the drug in many different ways," said Dr. El-Shahawy. "For younger adults, that means talking about the risks of vaping and combining multiple forms, while for people who prefer edibles, the message is to 'start low and go slow' because the effects take time to kick in."
According to Dr. El-Shahawy, the team next plans to examine why people choose one method over another—for example, whether those who favor edibles are using cannabis for pain or sleep.
The researchers cautioned that the findings rely on the participants' self-reports of their cannabis use and that some use may have been underreported. In addition, the study could not establish cause and effect.
Funding for the study was provided by the National Institutes of Health grant R01DA055675.
In addition to Drs. El-Shahawy and Palamar, NYU Langone researchers involved in the study were Mohsen Abbasi-Kangevari, MD, MPH; Michelle He; and Xiaoying Zheng. Another study co-investigator was Neal Doran, PhD, at the University of California, San Diego.
