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Marijuana Can Cause This Awful Side Effect, Study Suggests

This will surprise you.
FACT CHECKED BY Emilia Paluszek

Marijuana's long reputation—both bad and good—is being re-evaluated these days, by the public, lawmakers, and scientists. Public approval of recreational marijuana use has never been higher, and a record 19 states have now legalized recreational use. The growing acceptance has led researchers to take a closer look at the side effects of cannabis, and one new study has found that pot can have an unexpected and potentially dangerous effect on your daily routine. Read on to find out more—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


What The Study Found

Woman in a bed holding her head in pain.

Marijuana is a well-reputed relaxant. But a new study has found that it might be frankly bad for sleep health. According to research published in BMJ, recent marijuana users were 34% more likely to report short sleep duration—less than six hours a night—than non-users.

People who used cannabis within the last 30 days were also more likely to oversleep—meaning more than nine hours a night—compared to non-users.

Recent marijuana users were also more likely to say they had difficulty falling asleep, staying asleep, or sleeping too much during the past two weeks. They were also more likely to tell their doctor they had trouble sleeping.


Heavy Users More Affected

girl in casual clothes smoking an electronic cigarette

Heavy cannabis users (meaning those who used the drug 20 or more days within the past month) were even more likely to report sleep problems. They were 64% more likely to experience short sleep duration and 76% more likely to have long sleep duration than non-users.

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Why That's a Problem

Female doctor in mask making notes in medical card while talking to patient at hospital

"Large population-based studies show that both short sleep and long sleep are associated with an increased risk of heart attacks and strokes, as well as the long-term progression of things like atherosclerosis, diabetes, coronary artery disease and any of the major cardiovascular diseases," the study's lead author, Calvin Diep, told CNN. "It seems with sleep there's kind of this 'Goldilocks phenomenon' where there's an amount that 'just right.'"

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How The Study Was Conducted

Man Smoking On Bright Sunny Day Outdoor

Researchers from the University of Toronto analyzed health data from 21,729 American adults, aged 20 to 59, from the National Health and Nutrition Examination Survey between 2005 to 2018. About 15% of respondents said they had used marijuana within the past 30 days. The study is considered representative of nearly 146 million Americans. 

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Marijuana's "Stimulant Properties" Potentially Bad for Sleep

"There has been a surge of interest in cannabinoids such as cannabidiol (CBD) in recent years as potential sleep aids for primary sleep-wake disorders such as insomnia, restless leg syndrome, central sleep apnea, obstructive sleep apnea (OSA), as well as for sleep disturbances secondary to other conditions such as chronic pain or post-traumatic stress disorder (PTSD)," the researchers wrote. "In contrast to CBD, current evidence suggests that delta-9 tetrahydrocannabinol (THC), the other major cannabinoid present in most strains of cannabis, has stimulant and hallucinogenic properties contributing to sleep disruption."

The researchers said that insomnia is one of the most common reasons people say they use marijuana, but so far there's little scientific proof it can help. "Currently, the only indications with some robust evidence for therapeutic cannabis use to improve sleep duration or quality are OSA, PTSD, and chronic pain syndromes," the researchers wrote.

And to get through this pandemic at your healthiest, don't miss these 35 Places You're Most Likely to Catch COVID.


Michael Martin
Michael Martin is a New York City-based writer and editor. Read more about Michael
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