Written By: Dr. Jonny Lisano, Ph.D.
Sleep: We all need it, but most of us can’t seem to get enough. We’ve all been there, the alarm goes off and you feel like you only fell asleep an hour ago, but could CBD help support natural sleep rhythms?
Cannabidiol, or CBD, is one of the two major phytocannabinoids found in cannabis along with delta-9-tetrahydrocannabinol, also known as THC. However, unlike THC, CBD does not produce intoxicating effects (which you can read more about here in one of our previous blog posts). There are anecdotal claims across the industry and consumers alike that CBD can help support healthy sleep, but what does the research actually say?
What is “Normal” Sleep?
Before we start discussing scientific research on CBD and sleep, we should first discuss the stages of sleep that make up the sleep cycle. There are four general stages of sleep, which can further be divided by the presence of rapid eye movement (REM). These two categories are non-REM, which the first three stages are in, and REM where the fourth and final stage of the sleep cycle occurs.
Non-Rapid Eye Movement
Non-REM Stage 1 (N1): Light sleep
This stage is the transition between wakefulness and sleep. In this stage of transition, brain waves known as “theta waves” first make an appearance. During this stage of sleep, you can be easily awoken by sounds or touch. This is also the stage of sleep where hypnic jerks occur and involuntary muscle contractions can momentarily startle you awake. This stage typically lasts 10-15 minutes per cycle.
Non-REM Stage 2 (N2): Moderate sleep
In the second stage of sleep, theta waves become more prevalent and are joined by two more brain wave complexes. These two new brain waves are known as k-complexes and sleep spindles. It is theorized that k-complexes help with memory consolidation and that sleep spindles aid in filtering out non-threatening sounds and touches to prevent you from being startled awake and disrupting the sleep cycle when your partner is tossing and turning, or when the dog is pacing back and forth across the wooden floor all night. So, while you are not yet in deep sleep it’s much more difficult to wake you up than it would be during N1.
Non-REM Stage 3 (N3): Deep sleep
This stage of Non-REM sleep is commonly referred to as slow-wave sleep or deep sleep. That is because, during this stage of sleep long, slow delta waves become present and characterize the onset of this sleep stage. In this stage of sleep, it is extremely difficult for your body to be woken-up. If you’ve ever been jolted awake in the middle of the night by a loud sound but your roommate or partner is still sleeping peacefully, it’s most likely because they were in the N3 stage of sleep while you were in one of the lighter stages of sleep (N1, N2, REM). This stage of deep sleep is where your body secretes hormones like growth hormone to aid in tissue repair and recovery throughout your body. This stage of sleep is very critical, especially if you live an active lifestyle because this is where the majority of muscle repair and growth occur. So if you are an active individual, getting adequate deep sleep is essential to your recovery process.
Rapid Eye Movement
Rapid Eye Movement (REM): “Dreaming” Sleep
This stage is called rapid eye movement (REM) because during this stage a sleeping individual’s eyes will move back and forth rapidly signifying that dreams may be occurring. The deepness of this stage of sleep is not to the extent of that of N2 or N3 and you can be easily awoken. This stage is often referred to as paradoxical because your brain activity mimics that of being awake but your body is physically inactive. This is because during this stage of sleep your brain prevents your body from physically acting out your dreams, keeping you and anyone sleeping near you safe. This stage of sleep typically lasts in 15-20 minute intervals.
While a complete sleep cycle lasting anywhere from 90 to 120-minutes can include all 4 stages, they do not typically occur in sequential order and then start over for the next sleep cycle. You typically progress in the following order: N1, N2, N3, N2, REM and then either go back to N1 or back to N2 starting the cycle over again. We typically have more deep sleep at the beginning of the night, and more REM sleep towards the end of the night. During a “good night’s sleep” you’ll most likely complete anywhere between 4-5 complete cycles. Also, waking up at the completion of a cycle will lead you to feel more rested than if you are awoken in the middle of a cycle. However, as most of us know this is not always the case. Factors like stress, anxiety, pets, and kids are but just a few factors that can disrupt our sleep habits. You can see below in Figure 1 the difference in the sleep cycle progression during a good night’s sleep and a bad night’s sleep. Panel A of Figure 1 depicts a “good night’s sleep” with no times of awakeness during the night and the majority of time spent in the light (N1, N2), deep (N3) and REM stages of sleep. To the right in panel B of Figure 1, you can see an example of a “bad night’s sleep”, and the interruptions of periodically waking up throughout the night, disrupting the natural sleep stage rhythm.
Sleep data was collected from a 33-year-old female on seperate nights
Research on CBD and Sleep
Questions around CBD and sleep have been gaining in popularity, begging the question “Could CBD help support natural sleep habits, leading to a more restful night’s sleep?” Let’s see what we currently know from the research.
It is well established that anxiety can elicit changes in the sleep cycle and disrupt natural sleep habits. A study from 2012 using a rat-model of anxiety found that the injection of CBD into the central nucleus of the amygdala (yes, that means they injected CBD directly into a specific area of the rat’s brain), known as the “fear center” of the brain, blocking the anxiety-induced suppression of REM sleep. In other words, CBD helped increase the duration of REM sleep in rats suffering from anxiety (Hsiao 2012). Yet, there was no significant effect of CBD on overall sleep duration. The implications of this study are hard to determine, however, as it was done in an animal study, and CBD was injected directly into the brain, which makes it difficult to determine whether there are any real-world implications of this. So, what about some other studies that don’t involve brain injections?
Another study published in 2013 assessed sleep duration in rats receiving either 2.5, 10 or 40 mg of CBD per kilogram of body weight. However, keep in mind that due to pharmacokinetics of mammals a 2.5 mg/kg dose of CBD in a rat is not equivalent to 2.5 mg/kg in a human. Instead, the human equivalent doses of 2.5, 10 and 40 mg/kg in rats would be more comparable to doses of 0.20, 0.81 and 3.25 mg/kg respectively. In a 150 lb adult, this would equate to taking doses of ~14, 55, or 220 mg, which are reasonable doses for a human. Interestingly enough, there was no difference in sleep duration in animals receiving the lowest dose of CBD compared to the control group; however, in both of the higher CBD dose groups, there was a significant increase in overall sleep time, suggesting that taking a human equivalent dose of ~55 mg of CBD prior to bedtime could increase sleep duration (Chagas 2013). Yet, as interesting as the results of this study are, like the first study, it was still performed in an animal model and despite the promising results is still not directly applicable to humans.
A case study of an adolescent suffering from post-traumatic stress disorder (PTSD), a severe form of anxiety, found that the administration of 25 mg of CBD prior to bedtime decreased the patient’s sleep scale score from an initial score of 59 to a final score of 38 on the Sleep Disturbance Scale for Children (a score above 50 indicates sleep disorder on this scale). It was also noted that by the end of the case study that the child was sleeping in her own room most nights and reported no side effects from their CBD use (Shannon 2016), but what about the effects of CBD on sleep in adults?
Remember how we learned that when your body enters REM sleep that our body secretes chemicals to keep us from acting out our dreams? Well, there is also a condition called REM behavior disorder (RBD). Individuals suffering from RBD do not secrete the proper chemicals to keep their body from acting out their dreams, and can often cause them to act out vivid or unpleasant dreams through shouts and violent arm and leg movements. Researchers on a study from 2014, assessed if the administration of CBD in individuals suffering from RBD had any changes in their symptoms resulting from this condition. The four participants received anywhere from 75-300 mg of CBD prior to bedtime and saw a significant decrease in the number of RBD related events, and again similar to the previous study did not report any serious side effects (Chagas 2014).
Further, in a relatively healthy population, a study assessed the sleep quality of 25 patients from a psychiatric clinic over the course of a 3-month period using the Pittsburg Sleep Quality Index (PSQI). They found that the administration of CBD right after dinner improved sleep quality from initial assessment to the one-month reassessment, and remained lower compared to baseline till the end of the study at 3-months. Most subjects (>90%) self-administered 25 mg of CBD following their dinner, but some subjects reported using as much as 75 mg (Shannon 2019). The range in doses administered to participants in this study could be due to multiple factors including participant body weight. As we discussed in a previous article, the reason that participants consumed their CBD with a meal is that it can increase CBD’s absorption and bioavailability, which you can read here. Of the 5 studies we have discussed thus far, this is probably the most applicable to those seeking to use CBD products to support natural sleep rhythms.
It is important to note, as we wrap things up for this post, that not all cannabinoids are created equal with respect to sleep. In our role as researchers, we often get asked about cannabinoids for sleep, but THC and CBD have vastly different effects on our sleep architecture. For example, THC has been shown to decrease the time it takes individuals to fall asleep (Tringale 2011), but these subjects also experienced a lower quality of sleep (Ogeil 2015), less time in moderate to deep sleep (Nicholson 2004) and experienced overall less time sleeping (Gorelick 2013), which over the long term can have detrimental effects on our sleep habits. In a different study aimed at understanding user preferences when using cannabis for sleep, some adult participants reported that they preferred a cannabis product with higher CBD and lower THC (Belendiuk 2015) over the long term. At the time of writing this article, there have been no known detrimental effects of using only CBD for maintaining healthy sleep architecture.
While the current research shows promising effects for the use of products containing CBD to promote natural sleep habits, more research is still needed to identify the underlying physiological mechanisms, as well as the direct effects on the four stages of sleep we discussed at the start of this article.
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Disclaimer: Part of our mission is to always present the latest cannabinoid research; however, none of this is intended to represent the safety or efficacy of our products. These statements and our products have not been evaluated by the FDA, and our products are not intended to diagnose, prevent, treat or cure any disease. You should consult your physician or other health care professional before taking CBD to determine if it is right for your needs.