Vaping and smoking cannabis have increased over time, with more participants initiating use than quitting.
RT’s Three Key Takeaways:
- High rates of co-use – Simultaneous use of cannabis with nicotine and tobacco products is common, especially among young adults who vape, with dual cannabis–e-cigarette use prevalent across genders.
- Growing and diverse cannabis consumption – Cannabis use increased over time, with more participants initiating than quitting, and young adults using multiple forms such as vapes, edibles, smoked products, CBD, and topicals.
- Public health implications – The complexity, rising frequency, and expanding variety of cannabis products highlight the need for stronger surveillance, research on health effects and contaminants, and targeted education about the compounded risks of cannabis–nicotine co-use.
Simultaneous use of cannabis with nicotine and tobacco products is common among cannabis users—particularly those who vape—according to a new study published in Tobacco Induced Diseases.
Researchers from Columbia University Mailman School of Public Health found that both vaped and smoked cannabis use have increased over time, with more participants initiating use than quitting. Until now, the frequency, patterns, and motivations for cannabis use in early adulthood have remained understudied.
The study reveals that young adults in the New York City area—including those who do not vape or smoke nicotine—use multiple forms of cannabis, such as vapes, edibles, and topicals. Cannabis is the third most commonly used drug worldwide. In 2023, an estimated 61.8 million people—22% of Americans ages 12 and older—reported using marijuana at least once in the past year.
“Cannabis use in the US represents a multifaceted and evolving public health challenge that has, for too long, been overlooked,” said Katlyn McGraw, PhD, postdoctoral research scientist of Environmental Health Sciences at Columbia Mailman School. “We aimed to better understand use patterns and potential exposure to cannabis-related contaminants and associated health effects. Our findings show that cannabis use is diverse, complex, and growing—underscoring the need for further investigation.”
To examine trends in cannabis use and product types, the research team analyzed data from the VapeScan longitudinal study, designed to evaluate subclinical health effects of e-cigarette use. The cohort included 372 adults ages 18–50 in the New York City region assessed between 2021 and 2024, regardless of cannabis use status.
Participants were evaluated at three time points: baseline (visit one), approximately 12 months later (visit two), and approximately 24 months later (visit three). At the first visit, respondents completed questions about cannabis use. A more detailed questionnaire administered at visit 2 assessed longitudinal trends and specific methods of use. Participants were categorized as exclusive cannabis users, exclusive e-cigarette users, non–substance users, or dual users—those reporting daily or some-day use of both e-cigarettes and cigarettes.
At the first visit:
- 34% reported dual substance use
- 4% reported exclusive cannabis use
- 35% reported e-cigarette use without cannabis
- 28% reported no substance use
By the second visit, 59% of participants reported cannabis use:
- 29% vaped cannabis
- 28% smoked cannabis
- 51% consumed edibles
- 32% used CBD products
- 4% used topical cannabis
Frequency and intensity differed by product type. Importantly, self-reported vaped or smoked cannabis use changed between visits: 21% of participants were new users at visit two, while only 6% of those who vaped or smoked at visit one had quit. Rates of dual cannabis/e-cigarette use were similar between men and women.
“Frequent cannabis use is becoming more widespread and will likely continue to rise with changing social norms, policy liberalization, and the increasing availability and promotion of cannabis products,” McGraw noted. “The prevalence of cannabis use among teens and young adults is increasing, as is the variety of products—edibles, concentrates, vapes—adding to the complexity of studying health effects.
“As the third most widely used drug globally, understanding the health implications of cannabis is essential,” says Ana Navas-Acien, MD, PhD, chair of the Department of Environmental Health Sciences and senior author. “Our study highlights the importance of assessing cannabis exposure, including potential contaminants, and underscores that cannabis use is multifaceted. Regulatory policies and shifting consumer preferences further complicate efforts to accurately characterize exposure. Strengthening public health education that informs young adults about the compounded risks of cannabis–nicotine co-use is a first step.”
