A new study has found that millions more Americans are using cannabis and nicotine vapes in states that have allowed recreational marijuana sales. The findings are fuelling concern among experts who warn that today’s stronger cannabis strains and vaping devices could have significant long-term health consequences.

Published in JAMA Network Open, the research analysed data from 55,406 adults across 2013 to 2022. It revealed that monthly cannabis use rose by 3.28% and e-cigarette use by 1.39% after legalisation. This translates to an estimated 7 to 8 million new cannabis users and 2 million new vapers. Crucially, these rises accelerated once marijuana dispensaries opened.

Potency and dependence risks

Lead author Dr Andrew Hyatt, a Harvard Medical School instructor, noted that the rapidly rising potency of cannabis is changing the risk landscape. “While many people can use these substances without harm, we should be vigilant as to the effects on individuals predisposed to problematic substance use and mental illness,” he said.

Cannabis potency has surged dramatically since the 1970s, when THC levels hovered around 1–3%. Today, products in dispensaries often contain 18–23% THC, a level linked to addiction, psychiatric problems, and severe physical reactions such as nausea and uncontrollable vomiting. Experts argue this makes the cannabis legalisation health risks in the US far more concerning than advocates originally suggested.

Nicotine vaping: another pathway

The study also highlighted the link between marijuana use and nicotine vaping. Kevin Sabet of Smart Approaches to Marijuana described cannabis and nicotine as “two inextricably linked addiction pathways.” He warned that nicotine, already highly addictive, can prime younger generations for broader substance use, magnifying the dangers of marijuana legalisation on public health.

Despite this, marijuana advocates downplayed the risks, arguing the rise reflects an adjustment period. Jerry Joyner, host of the “Weed & Whiskey” podcast, insisted that education and responsible use should take priority over “scare tactics.”

A stalled movement

Legalisation efforts have slowed since 2023, with no new states joining the 24 that already permit recreational use. At the federal level, President Trump has resisted lifting the nationwide ban, even as state officials wrestle with rising health concerns and lagging tax revenues. Some states, including Montana, have responded by limiting the THC content of cannabis edibles, particularly after a spate of poisonings among children.

Meanwhile, studies continue to raise red flags. A June report in JAMA Health Forum linked marijuana legalisation to higher rates of opioid addiction among Veterans Health Administration patients, particularly middle-aged and older men with chronic pain.

Balancing risks and choices

Experts say society must reckon with whether increased access to cannabis truly delivers social benefits, or whether the cannabis legalisation health risks in the US outweigh them. Stanford University psychologist Keith Humphreys cautioned that marijuana is no longer a “weak drug used occasionally.” With almost half of cannabis users now consuming daily, the dangers of marijuana legalisation demand closer scrutiny.

Source: Washington Times