Many users believe that smoking cannabis helps with sleeping, but science says otherwise.

Smoking marijuana may cause sleep impairment. Photo by Chuck Grimmett.

Contrary to the popular perception that marijuana treats insomnia, a new study has found that heavy smokers report more sleep disturbance than people who use marijuana less often or not at all. The study, published in January 2016 in the Journal of Addictive Diseases, notes that daily marijuana users scored higher on the Insomnia Severity Index and sleep-disturbance measures.

Boston University’s Michael Stein, author of the study, reports:

“Better sleep is one of the positive effects that marijuana users swear by, but there has been relatively little careful research on this topic,” Stein says.

Their research, which employed 98 marijuana users, most of them in their 20s, reported that a third of young adults (ages 18-25) complain of sleep problems, and there is an association between sleep disturbance and marijuana consumption.

“The effects of marijuana on sleep in intermittent users may be similar, in part, to those of alcohol, where improvements in sleep continuity measures have been reported with intermittent use, (but) daily use results in the worsening of sleep,” the researchers write.

Of course, correlation does not imply causation – in other words, even though there is a strong correlation, the study didn’t analyze if the marijuana itself is causing the sleep issues. Also, the sample size is not impressive and the results need to be replicated on more volunteers.

But the study does raise a valid problem. Many of the popular beliefs abut marijuana consumption have no science whatsoever behind them, and this is an issue we should fix. Stein urges for more research on the topic, so that health providers can talk more clearly to marijuana users about effects on sleep, and drug-treatment providers could “meaningfully target sleep” among heavy marijuana users.

Journal Reference: Journal of Addictive Diseases