There has been a long and common association between cannabis and sleep. For thousands of years, cannabis has been used to treat a lack of sleep and insomnia. However, a recent study published in the journal Regional Anesthesia & Pain Medicine suggests otherwise.
They found that adults who used weed 20 or more days during the last month were:
- 64% more likely to sleep less than six hours a night
- 76% more likely to sleep longer than nine hours a night
Here’s an objective look at the pros and cons of this study and what conclusions we can draw.
Why Is This Important?
Undersleeping and oversleeping regularly are associated with several health problems. Those who suffer from sleep problems have an increased risk of obesity, diabetes, high blood pressure, cardiovascular diseases, stroke, dementia, depression, and a weaker immune system. Those who have insomnia for a long time may also experience joint and bone pain.
What Does the Study Say?
The study analyzed the use of marijuana for sleep among 21,729 adults between the ages of 20 and 59. A cross-sectional analysis of adults was undertaken using the National Health and Nutrition Examination Survey data from 2005 to 2018. The study identifies three buckets of sleep:
- Short sleep = under six hours
- Optimal sleep = six to nine hours
- Long sleep = over nine hours
The study found that recent users were more likely than non-users to report short and long sleep.
There does appear to be a dose-dependent effect, with recent and heavy users (those who use cannabis 20 or more times a month) even more likely to be at the extremes of nightly sleep duration. More moderate marijuana use (less than 20 times a month) did not result in short sleep, but people were 47 percent more likely to snooze nine or more hours a night.
People included in the study who used cannabis within the past 30 days were also more likely to have trouble falling asleep or have discussed their sleeping problems with a healthcare professional.
What Can We Conclude From the Study?
Despite the large sample size, the only thing we can say for definite is that using cannabis can somehow affect sleep. The study does not prove a causal relationship between cannabis use and the development of sleep disorders. It’s just as reasonable to say that people suffering from sleep disorders use cannabis as a therapeutic tool.
Sleep disorders can also arise due to other health problems, and cannabis could help treat these. For example, someone who has insomnia due to arthritis and chronic joint pain could find some relief from cannabis. In contrast, another person who uses too much THC and suffers from anxiety may find that cannabis is not having the sleepy effect they desired.
The study found that dosage matters. The cannabinoids and terpenes utilized by a person also count as some types of cannabis that may have more energizing effects.
Cannabis is a complex plant, and not all varieties have the same chemical composition. Someone using cannabis with a greater deal of precision (i.e., they’re a medical patient carefully measuring their dosing and keeping an eye on cannabinoid content) may not suffer from the same side effects. A person can also use cannabis as an alternative to sedatives or even alcohol, which have many problems, including addiction and overdose.
Essentially, there are a lot of confounders that need to be taken into consideration. We could be putting the cart before the horse.
Is There Any Other Evidence Supporting the Study?
To a certain extent, there is some limited evidence. Other studies have shown that:
- Cannabis withdrawal may also contribute to sleep problems — but these studies did not always do the best job of controlling for confounders.
- Cannabis may increase the amount of time in deep sleep — but once again, the confounders are not adequately controlled for, and the results are mixed, with some studies showing a decrease and others an increase in REM stage sleep, alongside the studies being biased.
- One randomized, double-blind, placebo-controlled study found no acute effects of cannabidiol (CBD) on the sleep-wake cycle. However, CBD alone is not necessarily very effective for insomnia. Tetrahydrocannabinol (THC) and cannabinol (CBN) may be more beneficial for insomnia due to their ability to bind with CB1 receptors (CBD doesn’t do this and so cannot directly induce sleepiness on its own).
- Other studies have come to similar conclusions – intermittent and short-term use may help treat insomnia, but regular use for longer than two weeks may be harmful.
- Overuse of THC in those suffering from anxiety may contribute to sleep disturbances rather than solve them — low doses of THC, however, may still help treat insomnia resulting from anxiety.
Although these studies suggest that using cannabinoids can affect sleep, and we know that endocannabinoid signaling is essential in regulating the sleep-wake cycle, there is no hard-and-fast evidence that using cannabis plays a role negative part in all of this.
Is Cannabis Still Useful for Treating Insomnia and Sleep Disorders?
Just as with any medicine, cannabis can be used and misused. There are also many variables and confounders that you have to consider when looking at any medication in the real world. Cannabis, with its hundreds of active compounds in various concentrations, makes teasing apart these variables in a real-world context even more difficult. So, just because some studies show potential adverse effects doesn’t mean there aren’t positive ones. Some of these we have already stated above, but bear repeating:
- Some people may be using cannabis to treat insomnia and replace sedatives effectively.
- Other randomized, double-blind, placebo-controlled, crossover studies have shown that two weeks of nightly sublingual administration of a cannabinoid extract is well-tolerated and improves insomnia symptoms (total sleep time, sleep onset, feeling rested on waking) in 23 of 24 patients.
- Insomnia resulting from other health concerns like chronic pain may be well treated by cannabis (although once again, this study suggests that dosing and tolerance developed from frequent medical cannabis use may reduce its efficacy for insomnia).
- Over-reliance and tolerance building up due to overuse of THC may reduce its efficacy for insomnia — careful dosing, utilizing a variety of cannabinoids and terpenes (e.g., myrcene, humulene, linalool) and, if it doesn’t cause any danger to your health, the occasional tolerance-break may help.
- Research on cannabis and its effect on sleep is still in its infancy. One literature review suggests that CBD may hold promise for treating REM sleep behavior disorder and daytime sleepiness, which is a contrast to its use as a treatment for insomnia, mainly as some people have found CBD to be more uplifting due to its ability to indirectly act as a negative allosteric modulator of the CB1 receptor, which reduces the potency of THC.
- The same study suggests that nabilone (a synthetic form of THC) may help treat insomnia and reduce nightmares associated with post-traumatic stress disorder (PTSD).
- Another study into CBD’s therapeutic potential for treating poor sleep associated with anxiety showed positive results. Anxiety scores decreased for the study duration (at least one month), whereas sleep scores improved for one month but fluctuated after that.
The Botton Line: How Much Cannabis You Use Matters
As there are so many studies showing conflicting results, it seems wise to pick up on specific patterns that can be observed throughout, whether or not the results are positive. Some observations include:
- Cannabis and cannabinoids may help treat insomnia in the short term, and tolerance can form. One can mitigate this by using different cannabinoids other than high doses of THC, careful dosing (i.e., don’t use too much THC), and the occasional break wherever possible.
- Cannabinoids are still a viable alternative to sedatives for more severe cases of insomnia.
- It seems to matter what condition the insomnia is comorbid with — insomnia with anxiety may require less THC, whereas insomnia related to PTSD or chronic pain may require more THC.
- Many studies don’t consider confounders, making it difficult to draw definitive conclusions.
More studies into cannabinoids’ effect on the sleep cycle are certainly merited if we want to find an answer to whether cannabis helps or hinders sleep.