Marijuana Use Linked to Daytime Sleepiness, Non-Restorative Rest

Studies show--marijuana can make you lethargic and lazy. Previous research has suggested that long-term use of the drug can lower the dopamine levels in your brain or the centers associated with motivation. Yet marijuana use also can disrupt sleeping patterns, despite the drug's ability to make you feel tired.

Researchers from the University of Pennsylvania in Philadelphia found that those with a history of cannabis use reported an increased likelihood of difficulty falling asleep, struggling to maintain sleep, experiencing non-restorative sleep and feeling excessively sleepy during the daytime. In fact, findings showed that for users who started smoking marijuana before the age of 15, they were twice as likely to have severe problems with falling asleep as well as daytime sleepiness or non-restorative sleep patterns.

"Current and past marijuana users are more likely to experience sleep problems," said lead author Jilesh Chheda, research assistant at the University of Pennsylvania in Philadelphia, working with Dr. Michael Grandner, the senior author on the study, via a press release. "The most surprising finding was that there was a strong relationship with age of first use, no matter how often people were currently using marijuana. People who started using early were more likely to have sleep problems as an adult." 

For the study, researchers examined adults from 20-59 years old who responded to the 2007-2008 National Health and Nutrition Survey (NHANES). The information assessed the drug history reported by 1,811 participants and their cannabis use, along with age and number of times they had used the drug in the past month. Sleep-related problems were considered severe if they occurred within the last 15 days per month.

The study results suggest that marijuana use during adolescence may increase the risk of subsequent insomnia symptoms, including stress. However, insomnia may be a potential reason why some continue marijuana use.

 "Marijuana use is common, with about half of adults having reported using it at some point in their life," Chheda added, via the release.  "As it becomes legal in many states, it will be important to understand the impact of marijuana use on public health, as its impact on sleep in the 'real world' is not well known."

More information regarding the findings will be presented Wednesday, June 4, in Minneapolis, Minnesota, at SLEEP 2014, the 28^th annual meeting of the Associated Professional Sleep Societies LLC.