Millions of Americans use marijuana to sleep, but new study raises troubling questions

Marijuana may be making sleep quality worse, despite its widespread use as a sleep aid, a recent Northwestern Medicine study found.

The findings of the study, which included 1,266 participants, showed that both lifetime and recent cannabis users objectively had worse sleep quality, although they did not report their sleep to be worse.

Participants were monitored for almost 35 years, from young adulthood into middle age, with scientists tracking their use of cannabis over time.

AMERICA HITS MAJOR MARIJUANA MILESTONE AS DAILY WEED USE SURPASSES DAILY DRINKING

In middle age, participants wore a sleep monitor on their wrist for a week and filled out surveys about their .

This allowed researchers to compare objective and subjective reports of participants sleep.

"Our data do not support the belief that cannabis is helpful as a sleep aid," said senior study author Mercedes R. Carnethon, Ph.D., as Northwestern Now reported.

"As increasingly available and accepted, it's important to better understand its long-term associations with health behaviors such as sleep," Carnethon added.

Among all participants, a greater lifetime exposure to marijuana was linked to worse objective sleep quality.

Those who had a higher cannabis usage over time were generally asleep for a lower percentage of the night and experienced more sleep disruption.

Similarly, recent cannabis users were more likely to have more sleep fragmentation and lower sleep efficiency, compared to people who never used the substance.

The study also found there was a much higher chance that recent cannabis users would sleep longer than eight hours per night. 

The study discusses the differences between objective and subjective reports of sleep quality.

"What makes this study particularly interesting is that participants who used cannabis demonstrated objectively poorer sleep, yet their own assessments of sleep quality did not reflect those differences," Alfred Joshua, M.D., a board-certified emergency medicine physician based in California, told Fox News Digital. (He was not involved with the new study.)

"In other words, someone may believe marijuana is helping them sleep, while objective measurements suggest otherwise." 

Researchers considered multiple outside factors including age, race, sex, smoking frequency, alcohol consumption, and more.

Even with these factors taken into account, the study found a consistent correlation between cannabis use and poorer objectively measured sleep.

The mode of cannabis consumption, such as smoking versus taking edibles, was not considered.

"It is not surprising that the actual quality of sleep of these subjects, after chronic marijuana use, is poor compared to those who do not smoke marijuana because people who claim that they need to smoke marijuana before they go to sleep, in order to relax, are only kidding themselves," board-certified psychiatrist Carole Lieberman, M.D., of California told Fox News Digital. (She, too, was not affiliated with the new study.)

"It is more a psychol