When asked why people smoke marijuana regularly, many will reply that it helps them fall asleep.
Insomnia and other sleep disorders are very common in industrialized countries, with stress, worry, noise, light pollution, illness, and many other factors playing a part.
As people search for solutions to their sleep problems, marijuana is often considered, particularly with the rise in the availability of medical and recreational marijuana over recent years.
But does this perceived increased ability to fall asleep actually lead to more rapid and deeper sleep? If so, will it stay as effective after chronic use, and what about the possibility of dependency?
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Additionally, for those who follow the science behind cannabis, the question of which compounds in weed are responsible for the onset of sleepiness may arise. Is it possible to take a cannabidiol (CBD) only product and experience benefits to sleep quality without the “high” feeling?
In this article, we will explain what researchers have found with regards to cannabis and cannabinoids in relation to sleep.
Cannabidiol, also known as CBD oil or hemp oil, is a non-psychoactive cannabinoid found in the Cannabis Sativa plant.
Cannabis sativa is the plant to which both marijuana plants and industrial hemp plants belong. While the same plant, marijuana plants have been bred to have higher levels of THC (tetrahydrocannabinol), the psychoactive compound found in weed, and hemp plants higher levels of CBD, a non-psychoactive compound that has recently been the center of attention for many who desire the therapeutic benefits of cannabis without the mental alterations.
THC and CBD belong a class of over 80 cannabinoids found in cannabis, along with hundreds of other compounds. Cannabinoids specifically are being targeted for the treatment of a wide variety of illnesses, with numerous therapies existing that are either a combination of these phytocannabinoids or synthetically produced cannabinoids.
The therapeutic benefits of cannabinoids in our bodies are believed to be largely thanks to the Endocannabinoid System (ECS).
Our bodies produce their own cannabinoids, termed endocannabinoids. These endocannabinoids act on cannabinoid receptors found throughout our peripheral and central nervous systems. To maintain balance, our bodies also produce metabolic enzymes that break down these endocannabinoids.
There exist two cannabinoid receptors: CB1 and CB2.
CB1 receptors are found in the brain areas associated with energy homeostasis, emotion, motivation, and motor control.1 Additionally, CB1 receptors are found in the adipose (fat) tissue, skeletal muscles, heart, liver, pancreas, GI tract, and reproductive system.
CB2 receptors are involved in regulating the immune response, with their expression mainly throughout immune tissues and cells.
THC has an affinity for CB1 receptors, which is believed to be the reason for THC’s impact on our neurocognition.
CBD has little affinity for either the CB1 or CB2 receptors but instead acts through a variety of other mechanisms. One of these is through the inhibition of FAAH, an enzyme that breaks down the endocannabinoid anandamide. By inhibiting FAAH, CBD can lead to increased anandamide levels in the body.
With the wide variety of roles of the ECS, the promise of targeting this system for future therapeutic approaches for those suffering from a wide array of diseases is of interest to both scientists and the general public.
As medical marijuana and Cannabis sativa products, such as CBD hemp products, have been gaining increased legality and becoming more widely available, research into this area has taken off, as have personal accounts of these products helping with a wide variety of symptoms.
Findings from published scientific studies of CBD and sleep have shown contradictory results. (2)
Differences in methodologies, such as how the CBD was administered (oral CBD, injectable CBD, etc), the quantity of CBD, or variables in test subjects may explain these and other differing results.
Here we will review relevant research findings along with detailed methodologies in order to see if there is a pattern to help guide consumers in the right direction as to the use of CBD for sleep.
Numerous animals studies have found CBD to encourage alertness in healthy subjects.
In a 2008 study published in Behavioral Neuroscience, the effect of CBD injected into certain brain areas on sleep quality and wakefulness was examined. (2)
Rats were injected with either a control vehicle, CBD at 10 µg/µl, or CBD at 20 µg/µl at 7:00 into one of two wake-inducing brain areas, the dorsal raphe nuclei or the lateral hypothalamus. For the next 4-hours during the light period of the day, sleep-wake recordings were taken every 12 seconds, along with measures of sleep quality, such as delta, theta, and alpha frequency bands.
These researchers found that rats in the CBD groups experienced a dose-dependent increase in total time awake and experienced diminished REM sleep and slow wave sleep when compared to control rats during the light period of the day.
In a 2013 study published in the Journal of Psychopharmacology, rats were given 2.5 mg/kg CBD, 10 mg/kg CBD, 40 mg/kg CBD, or a placebo. Sleep recordings were made during light periods and dark periods for four consecutive days: two days of baseline, one day of CBD or placebo administration, and one-day post-test.
The researchers found that the total percentage of sleep during the light period of the test day was significantly greater for the 10 and 40 mg/kg CBD compared to the placebo group. On the day following treatment, REM sleep latency (the time that it took the rats to enter REM sleep) was increased in the 40 mg/kg CBD group and significantly decreased in the 10 mg/kg group when compared to the placebo.
This study found that CBD may increase total sleep time in the light period of the day CBD is administered.
Interestingly, the time it took to reach REM sleep the following day was longer for rats who were given 40 mg/kg CBD and shorter for rats who were given 10 mg/kg CBD. This finding is similar to that of many studies which have found a dose-dependent bell curve, meaning that CBD may become less effective in quantities greater than the most effective dose.
In a 2006 study published in FEBS Letters, researchers examined sleep in rats administered intracerebroventricular (icv) CBD in 10 µg/µl at the beginning of both the light-off and lights-on periods. (4)
Rats who were given a CBD injection during the lights-on period experienced increased wakefulness and decreased REM sleep, with the rats given injections during the lights-off phase not experiencing any changes.
Upon further examination, the researchers found that CBD induced an increase in dopamine release and activated neurons in the hypothalamus and dorsal raphe nucleus, regions of the brain involved in generating alertness.
These findings suggest that CBD may be helpful for those who suffer from disorders that lead to excessive sleepiness.
While most animal studies have found that cannabidiol reduces both REM and non-REM sleep in healthy rats, this pattern may not hold true for those who are suffering from a variety of health conditions.
CBD has been shown to have anti-anxiety and pain-relieving effects, which has led researchers to question if CBD could help those who suffer from sleep disturbances due to conditions with high levels of anxiety or pain.
In 2012, researchers published a study in Neuropharmacology on rats with induced PTSD to determine what effect CBD would have on their sleep.
The researchers found that CBD injected into the central nucleus of the amygdala of rats with PTSD not only led to fewer symptoms of PTSD, but also to an efficient blocking of the anxiety-induced REM sleep suppression found in rats with PTSD.
This study demonstrated that, for certain conditions linked with high levels of anxiety, CBD may have a positive impact on sleep quality. Rather than this effect being through sleep regulation, it appears to be through its anxiolytic effects.
In a 2016 study published in The Permanente Journal, a ten-year-old girl who was suffering from PTSD following sexual abuse was treated with cannabidiol oil when pharmaceutical medications did not offer full relief and induced unwanted side effects. (6)
Over a period of 5 months, the patient received one 25 mg CBD supplement nightly along with a sublingual CBD spray ranging from 6 g to 12 mg as needed for anxiety symptoms.
During this period, a gradual decrease in her anxiety and an increase in sleep quality and quantity were noted. No side effects of the CBD supplement or spray were observed.
The researchers concluded that CBD may be effective at reducing the anxiety and consequent insomnia and sleep disturbances that originate from PTSD.
A study published in 2014 in the Journal of Clinical Pharmacy and Therapeutics studied the effect of cannabidiol on four Parkinson’s disease patients. (7)
REM sleep behavior disorder (RBD) can occur in Parkinson’s patients and is characterized by nightmares and active behavior during dreaming that impairs the patient’s ability to sleep. These four patients were treated with between 75 and 300 mg/day of CBD for six weeks.
All four patients experienced a fast and substantial reduction in the frequency of RBD events with no reported side effects, leading the researchers to conclude that CBD may be able to control symptoms associated with RBD.
Numerous studies have found that the anxiolytic effects of CBD may help those who suffer from anxiety conditions sleep better, and other therapeutic effects may lead to CBD improving sleep quality in patients with Parkinson’s disease.
More studies are needed to replicate these results and discover if there are other health conditions that cause sleep disturbances which may be mediated with CBD oil and related products, as well as to further understand the mechanisms by which CBD is exerting these effects.
In 2007 published in Chemistry Biodiversity, a summary of Phase I-III studies involving 2,000 subjects suffering from a variety of pain disorders who have taken Sativex was completed. (8)
Sativex is an oromucosal spray consisting of a 1:1 ratio of THC:CBD. Subjective sleep parameter improvement was demonstrated in patients suffering from a wide variety of conditions, including multiple sclerosis, intractable cancer pain, rheumatoid arthritis, and peripheral neuropathic pain.
The findings demonstrated an acceptable adverse event profile with no buildup of tolerance during up to 4 years of Sativex administration.
The answer to this question based on the studies outlined about is that CBD may both improve sleep and reduce insomnia or encourage wakefulness, depending on the situation.
In healthy individuals, CBD appears to work as a wake-inducing agent, which may offer help for those who suffer from conditions with extreme drowsiness. As most of these studies have been on animals, more research is needed on human subjects to confirm if these findings hold true across species.
Contrary to this finding, for those who suffer from certain medical conditions, such as PTSD, where individuals suffer from sleeplessness or insomnia due to anxiety, or Parkinson’s disease, studies show promise of CBD oil in helping to relieve certain symptoms and improve sleep quality.
It is likely due to the pain-relieving and effects of CBD that these patients experienced improved sleep parameters.
Studies on the combination of THC and CBD also offer a hopeful therapeutic role for those suffering from sleep problems caused by a variety of chronic pain conditions.
1. Mouslech Z, Valla V. Endocannabinoid system: An overview of its potential in current medical practice. Neuro Endocrinol Lett. 2009;30:153–179.
2. Murillo-Rodriguez E., Millán-Aldaco D., Palomero-Rivero M., et al. The Nonpsychoactive Cannabis Constituent Cannabidiol Is a Wake-Inducing Agent. Behavioral neuroscience. 2009; 122:1378-82. doi 10.1037/a0013278.
3. Chagas MHN, Crippa JAS, Zuardi AW, et al. Effects of acute systemic administration of cannabidiol on sleep-wake cycle in rats. Journal of Psychopharmacology. 2013;27(3):312–316
4. Murillo-Rodriguez E, Millán-Aldaco D, Palomero-Rivero M, et al. Cannabidiol, a constituent of Cannabis sativa, modulates sleep in rats. FEBS Letters. 2006;580(18):4337–4345.
5. Hsiao YT, Yi PL, Li CL, et al. Effect of cannabidiol on sleep disruption induced by the repeated combination tests consisting of open field and elevated plus-maze in rats. Neuropharmacology. 2012;62:373–384
6. Shannon S., Opila-Lehman J. Effectiveness of Cannabidiol Oil for Pediatric Anxiety Insomnia as Part of Posttraumatic Stress Disorder: A Case Report. The Permanente Journal. 2016; 20(4):108-111. doi 10.7812/TPP/16-005
7. Chagas MH, Eckeli AL, Zuardi AW, et al. Cannabidiol can improve complex sleep-related behaviours associated with rapid eye movement sleep behaviour disorder in Parkinson’s disease patients: a case series. J Clin Pharm Ther. 2014;39:564–566
8. Russo EB, Guy GW, Robson PJ. Cannabis, pain, and sleep: lessons from therapeutic clinical trials of Sativex, a cannabis-based medicine. Chem Biodivers. 2007;4:1729–1743