Smoking heavy amounts of marijuana as a teenager could lead to sleeping problems as an adult, according to a recent study by the University of Colorado Boulder.
The study, published by the National Library of Medicine National Institutes of Health, compiled data from over 1,800 twins, surveying sleep habits, marijuana use and mental health from their teenage years to adulthood. According to CU, researchers found that nearly one-third of the study's participants who regularly consumed marijuana before turning eighteen had insomnia later in life.
"People tend to think that cannabis helps with sleep, but if you look closely at the studies, continued or excessive use is also associated with a lot of sleep deficits,” says Evan Winiger, a CU graduate student and lead author of the study.
Regular teenage marijuana users could have double the risk for "short sleep," or sleeping fewer than six hours a night on a regular basis, according to the study, which calculated the rate of short sleepers among marijuana users at 10 percent, compared to 5 percent of non-users.
Despite finding a correlation between regular marijuana use and sleeping problems, the study stopped short of determining why smoking pot might be linked to insomnia.
Winiger suggests that our body's endocannabinoid system — the set of receptors that pick up THC, CBD and other cannabinoids for their mind-bending or therapeutic effects — is flooded with cannabinoids when we consume marijuana, which could throw a wrench in our body clocks. “One theory is that these receptors are being desensitized or disturbed from all the cannabis use at a time that the brain is still developing, and that leads to waking issues later,” he adds.
However, the study points out that genetics could also play a role in our sleeping habits, and that people with sleeping disorders could be turning to marijuana for help, making the conclusion murkier. “It is possible that sleep problems could influence cannabis use, cannabis use could influence sleep problems, or common genetics could be responsible,” the study reads.
CU researchers could have more clarity on the subject in a few years, when a separate $5.5 million study headed by the university will finish monitoring how alcohol, cannabis and other substance use during adolescence affects the psychological health and social functioning of 2,500 sets of twins now in their twenties.