How Cannabis Works
There is a fair bit of interest in treating insomnia with cannabis, and the initial research shows that cannabis certainly has a significant impact on sleep. This seems to be in large part because of the way in which cannabis affects the human body’s endocannabinoid system.
The endocannabinoid system is one of the key systems in the human body, and it plays the important role of maintaining our body’s homeostasis (or internal balance). It can stimulate some of our bodies’ most important functions, such as:
Made of three main components, the endocannabinoid system is composed of endocannabinoids, enzymes, and endocannabinoid receptors. The endocannabinoids are chemicals produced by the human body, but interestingly, they have a lot of structural similarities to the cannabinoids in cannabis. When functioning properly, these endocannabinoids bond with endocannabinoid receptors (referred to as CB1 and CB2 receptors), which are found throughout the body on the surface of cells. Then, enzymes break down endocannabinoids, and clear them from our system.
Interestingly, the endocannabinoid system can also be stimulated by phytocannabinoids (some of cannabis’s active ingredients – usually just called cannabinoids). These molecules can also activate CB1 and CB2 receptors to stimulate these crucial bodily functions and restore balance. This is how cannabis can offer so many diverse and medicinal health benefits.
When it comes to sleep, activating these receptors could be particularly helpful, since endocannabinoid system signaling seems to regulate some aspects of our sleep. For instance, researchers have noted that the activation of CB1 receptors tends to induce sleep.
Studies on mice have also found that CB1 activation was associated with changes in the stability and length of non-rapid eye movement sleep (NREM) stages, which are crucial for getting a good night’s rest.
In addition, researchers also tested whether CB1 signaling was necessary for sleep homeostasis — the way in which humans account for lost sleep by sleeping more deeply and for longer periods when they are behind on rest. To do this, mice subjects were sleep deprived and had their CB1 signaling blocked. Still, blocking CB1 did not seem to reduce the amount of rebound NREM sleep after deprivation. When they were allowed to sleep, these mice still slept longer to account for the lost sleep. The authors say this work supports the idea that endocannabinoid signaling via CB1 is necessary for long and stable NREM sleep stages, but may not be necessary for sleep homeostasis in general.
So it’s clear that endocannabinoid signaling — particularly via CB1 — plays an important role in sleep regulation. Still, it’s not clear from this research exactly how cannabis might affect the sleep of humans when used to treat insomnia. For that, we will need to look at the clinical research.
Insomnia & cannabis
When it comes to cannabis and insomnia, there is a long history of people utilizing cannabis for better sleep. Since ancient times, people have noticed the sedating effects that come with some types of cannabis and have utilized it as a sleep aid.
Recent surveys of cannabis users also report similar trends. One 2018 survey of 1,000 cannabis users who purchase recreational cannabis found that 74% used marijuana to help them sleep, with 84% stating that it helped. Importantly, more than 83% also said they had reduced or stopped taking other sleep aids after switching to cannabis.
Still, the research on cannabis and sleep is still in early stages and experts are conflicted on whether it is a helpful solution, or one that may have long term negative effects. The dearth of research in this important topic is in large part due to the regulatory and legal status of cannabis until recently.
Some research points to cannabis’ ability to decrease the time it takes to fall asleep. For example, one study on physically healthy insomniacs tested the effects of THC on sleep patterns over a six week period. They found that THC significantly decreased the time it takes healthy insomniacs to fall asleep, and decreased the amount of time subjects woke up in the first half of the night.
In this study, subjects did experience one adverse effect — a hangover or continued high the next day. Since this increased with increased dosage, researchers recommended doses lower than 30mgs of THC.
Other research suggests that lower doses might be better for other reasons as well. One study found that cannabis has a dose dependant effect on the time it takes to fall asleep — decreasing time to sleep at lower doses, but increasing it at higher doses.
In addition to dose, strain and chemical composition may also have an effect on how cannabis impacts sleep. In one study, researchers examined cannabis strain preferences among cannabis users with sleep disturbances, and found that there were some notable trends. Those using cannabis to alleviate nightmares, for example, preferred sativa’s to indicas, while those who had current insomnia and also took longer to fall asleep tended to prefer strains with higher CBD. We should probably take any research on sativa/indica distinctions with a grain of salt, since it is often noted that the sativa/indica distinction doesn’t really mean much in terms of genetic or chemotype differences — this does point to the fact that some chemical profiles may work better for one aspect of sleep regulation, while another profile might work better for others.
Both these factors, along with genetic differences among medical marijuana users, might help to explain why some studies report benefits for sleep, while others say it might cause problems.
For example, some researchers argue that while THC may help some get to sleep faster, it could negatively impact sleep overall. One survey that supports this idea found that cannabis users tended to have more sleep disturbances than those who didn’t use cannabis.
Studies have also indicated the CBD could be helpful for sleep. A 2017 review of the literature found that CBD might be helpful for the treatment of both REM sleep behavior disorder (where people act out their dreams physically during REM sleep), and excessive daytime sleepiness.
While more research needs to be done to understand the different ways that cannabis can affect sleep, most of the reviews of the literature say that there is evidence that cannabis can help — particularly for those with sleep issues related to other conditions. For example, the National Academy of Sciences meta-review on cannabis from 2017 reported finding moderate evidence that cannabinoids can improve short-term sleep outcomes in patients with sleep disturbances associated with obstructive sleep apnea, fibromyalgia, chronic pain, or multiple sclerosis. So integration of cannabis into their regimen could help in multiple ways, including helping improve their sleep, which indirectly may improve their outcomes for the underlying condition, while also alleviating symptoms of chronic pain and other symptoms they may have.
A 2017 review from University of Pennsylvania agrees that cannabis can improve sleep for those with obstructive sleep apnea, and chronic pain, and also notes that cannabis may reduce nightmares associated with PTSD.
Still, both reviews caution that more research is sorely needed. While there is good evidence to point towards cannabis’ helpful abilities for sleep, we need more clinical trials on patients with insomnia to develop reliable cannabis treatments.