WEDNESDAY, June 4, 2014 (HealthDay News) -- People who use marijuana may have trouble falling and staying asleep and feel drowsy during the day, new research suggests.
And adults who started using the drug before they were 15 seem to be twice as likely as nonusers to have problems falling asleep, not feeling rested after sleep and feeling tired during the day, the University of Pennsylvania researchers said.
It's possible that people who already suffer from insomnia turn to marijuana as a way to help them sleep, said study lead researcher Michael Grandner, an instructor in psychiatry at the university.
"The type of person who reports marijuana use in the U.S. is more likely to also be the type of person who has sleep problems," he said. "It doesn't mean that one is causing the other."
It's more likely that people with sleep problems and stress may turn to marijuana as a way to self-medicate, Grandner said. "But there is little evidence, outside of anecdotes, to suggest that this will really help fix the problem in the long term," he said.
Rather than turning to marijuana to beat insomnia, Grandner suggests trying treatments that really work.
"For example, the most well-studied treatment for insomnia actually does not involve medications and works well -- it's called cognitive behavioral therapy for insomnia and essentially works by reprogramming your brain to sleep," he said.
Since the study found that those who started using marijuana earlier in life were more likely to have sleep problems, it may be important to help teenagers find healthier and more effective ways to cope with stress, Grandner suggested.
The study didn't prove that marijuana leads to sleep problems, just that there's an association between the two. It was scheduled to be presented Wednesday at the Associated Professional Sleep Societies' annual meeting in Minneapolis.
For the study, Grandner's team collected data on approximately 1,800 U.S. adults who took part in the 2007-2008 National Health and Nutrition Examination Survey. The participants reported how often they had used marijuana in the past month and at what age they began using it. They also reported whether they had any trouble sleeping. The researchers defined severe sleep problems as trouble sleeping at least 15 days a month.
The strongest link between marijuana use and sleep problems was found in adults who started using the drug before age 15. They were about twice as likely to have severe problems falling asleep, the study authors said.
The debate about marijuana has been heating up as it has been legalized in two states and approved for medical use in others.
Study lead author Jilesh Chheda, a research assistant at the University of Pennsylvania's division of mood and anxiety disorders, said in the Sleep Societies' news release: "Marijuana use is common, with about half of adults having reported using it at some point in their life. 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."
The federal government lists marijuana as a "schedule 1 substance" that has no medicinal uses and is a high risk for abuse, according to the U.S. National Institute on Drug Abuse.
Two states, Colorado and Washington, have legalized marijuana for adult recreational use, and 21 states allow its use for certain medical conditions, such as cancer and glaucoma.
Paul Armentano, deputy director of NORML, a group that lobbies for the legalization of marijuana, said the "association reported in this paper of a history of cannabis [marijuana] use and severe difficulty falling asleep is relatively minor and it is questionable whether it holds any real world relevance.
"The ongoing criminalization of cannabis and those who consume the plant is a disproportionate response to what is, at worst, a public health concern -- not a criminal justice matter," he added.
Health concerns about marijuana, particularly its potential use or abuse by young people, are best handled by regulation, public education and age restrictions, "not by criminalization and stigmatization," Armentano said.
For more on marijuana, visit the U.S. National Library of Medicine.