06.04.14 5:42 PM ET
No, Pot Doesn’t Cause Sleeplessness
If you give the public a marijuana sleep study, they’re going to want a conclusion to come with it.
So when a paper showing a link between poor sleep and early adolescent marijuana use came out—absent a firm conclusion on whether the latter causes the former—we drew our own.
Smoking Cannabis During Adolescence Can Cause Insomnia, read the initial headline on The Daily Mail’s post yesterday. Marijuana Could Turn You Into a Nighttime “Walking-Dead” Zombie, read a similar one in International Business Times. A handful of other stories followed, all either outwardly stating or subtly implying that early marijuana use can (and often does) cause a lifetime of sleepless nights.
But the study—an exploration of sleep problems as they relate to marijuana use—proved nothing of the sort.
Less than one week after the House of Representatives passed the first medical marijuana reform, the question of marijuana’s role in our lives is more important than ever. The dangers associated with the drug should not be buried. But while Congress’ new view on marijuana bodes well for the future of cannabis research, the truth is, it doesn’t make it any easier today.
Home to the only legal source of cannabis for researchers, the National Institute on Drug Abuse dispenses its pot to researchers who overcome the legal and financial hurdles that come with testing an illegal drug. The problem is, few achieve this. As a Schedule I Substance, marijuana is considered to have no medical purpose—so why would we need to study it? As a result of the Controlled Substances Act, doing so requires getting a special license from the Drug Enforcement Administration—both expensive and time-consuming. Few have gotten the necessary approval.
The doctors from this study weren’t one of them.
More an analysis of existing data than a breakthrough experiment, the study looked at marijuana use reported in the 2007-2008 National Health and Nutrition Examination survey (NHANES) responses. With ages ranging from 20 to 59, there were 1,811 participants who reported a history of drug use. The first age that the respondent used cannabis and the number of times respondents had used in the past month were both taken into account. Anyone who’d suffered more than 15 days of disturbed sleep in the past month was considered to have sleep problems.
But while the study undoubtedly shows marijuana use to be associated with sleep problems, it in no way implies that it causes it. The authors of the study made this clear, writing that the results were “not determined to show causality.”
In the aftermath of the study’s release, lead author Dr. Michael Grandner is quick to clarify that his study was not meant to imply that marijuana use is the only factor that caused sleeplessness in the respondents. “We cannot determine that. Actually, all we could document was that the people who endorsed marijuana use also endorsed sleep problems, and they tended to go together, especially if age at first use was under 15 years,” he tells The Daily Beast. “All we can say is that there is an overlap.”
Since the sample was taken from a survey initiated by the Centers for Disease Control to investigate health and related factors in America, it does reflect a nationally representative cross-section of the American population. The fact that the link transcended age group and demographic does speak to its relevance. “This study suggests that people who have sleep problems are likely to have tried marijuana in the past, and that current users have difficulty falling asleep,” says Gardner. “Perhaps marijuana is sedating and relaxing, but maybe it is not effective for insomnia in most people.”
Marijuana’s classification as a psychedelic does raise questions about its use as treatment for insomnia. But Amanda Reiman, policy manager for The Drug Policy Alliance, doesn’t believe this study is a viable option for exploring that question.
Reiman says there are a few things to question about this study. “First, among users, frequency of use was associated with severe difficulty falling asleep. The odds ratio here is 3 percent. In other words, users of marijuana have a 3 percent greater likelihood of experiencing severe difficulty falling asleep compared to non-users,” she tells The Daily Beast. “Also, this study had an extremely large sample size of over 3,000 people. The larger the sample size, the easier it is to detect an effect, even if it is very minor. If the sample size wasn’t over 3,000, this would have never been statistically significant,” she says.
She also points out that, while it let users describe their current sleep patterns, it didn’t provide information as to their sleep history as a whole. “This study does not address the issue that many people who have sleep disorders have had them since a young age, before the age of marijuana use,” she says. “So, it is very possible that those with sleep issues chose to use marijuana in an attempt to improve their sleep, which would show an overrepresentation of those with sleep problems in the marijuana use group.”
Whether or not marijuana improves or hinders sleep is still up for debate. As long as testing marijuana in the U.S. remains this difficult, there it will remain.