Many medical and recreational cannabis users report that cannabis helps them to fall asleep and improves sleep quality, while others report exactly the opposite. One of the issues complicating this field is that for many years cannabis was looked at as a single substance, when it is in fact it contains hundreds of compounds. So, when we talk about cannabis and sleep, we need to be specific about what we mean, which cannabinoids are we discussing? Previously on this site, we discussed how CBD influences sleep, so today we are going to explore in detail the effects of THC on sleep. According to a comprehensive review of the topic published in 2017, “the science behind cannabis use and sleep is still in its infancy.” However, there have been multiple studies and reviews published more recently which are beginning to elucidate the nuances involved in the connection between THC and sleep, as well as dreaming.
The big question on everyone’s mind is does THC, the most commonly sought cannabinoid of the recreational cannabis market, improve or hinder sleep? The short answer based on current research is yes, to both. It is a complicated relationship, especially when we are talking about a plant with many strains that can affect every user differently. Furthermore, the reasons why folks would turn to cannabis to improve sleep vary greatly from person to person, and although weed can help in some cases, in others it can actually harm sleep. To understand this relationship, we will first look at the role THC plays in normal sleep and then look at the conditions which cause sleep issues and how they can be affected by weed.
THC and sleep
Anecdotal evidence going back to ancient India, Greece, and the Middle East demonstrate the long-term application of cannabis is aiding sleep. In a 2017 study, it was shown that early sleep disorders in adolescence were also a predictor for later cannabis and alcohol abuse. However, scientific studies on cannabis and sleep such as clinical trials using polysomnography (PSG) (recording brain waves, O2 levels, heart rate, breathing, and rapid eye movements) did not begin until the 1970s. Over the last four decades, since that research began, we now know that the endocannabinoid system of the body plays a vital role in regulating the circadian sleep-wake cycle.
The main cannabinoid in cannabis, THC, has been found to increase sleep in several controlled studies. It has been shown to reduce sleep latency (the time it takes to fall asleep) in many users. These benefits are most profound in new, or irregular cannabis users, and then decreases with long-term or chronic use, indicating a tolerance effect. Furthermore, several other studies showed that the long-term effects of cannabis use are actually negative for sleep patterns, with decreases in REM sleep, less slow-wave sleep, increased daytime sleepiness, and decreased mental clarity.
Interestingly, some of these effects are actually counteracted by Cannabidiol, or CBD, which has shown to have more complicated effects on sleep. At low doses, it has been shown to act as a stimulant (around 10-20mg for a 68 kg person), and at higher doses (150-200 mg for a 68 kg person) as a sedative. CBD has been shown to have positive effects on those with chronic insomnia and has been shown to possibly mitigate the decreases in REM sleep observed with THC use. A 2006 study on rats found that CBD increased wakefulness, and thus may be helpful when used in the morning to regulate circadian rhythms, and could lead to decreased daytime drowsiness and improved concentration on tasks, particularly in those using THC to aid sleep.
Studies were done using a 1:1 THC: CBD formulation (Sativex®) have found that all sleep indicators were improved at low doses (5mg), including memory and performance on cognitive tests. However, those effects decreased at high doses, and also lead to the ‘hangover effect’ as well as increased sleepiness and decreased memory and cognitive function.
The above information demonstrates how complex the interactions between cannabis and sleep are. Furthermore, more recent studies have indicated that the terpenes and other phytocannabinoids also play an important role in sleep regulation, meaning that different strains of cannabis will affect your sleep differently. Interestingly, a recent survey of medical marijuana patients found that those using high CBD cannabis had fewer sleep improvements and that Sativa strains helped to decrease nightmares better than Indica ones in PTSD patients. However, the main consideration when thinking about how THC will affect your sleep applies to the reason why you are not sleeping, as some issues will be alleviated by THC, and others could actually be exacerbated by it.
Sleep problems and THC
People can have trouble sleeping for many different reasons, and as medical marijuana becomes more widely available some of them are turning away from traditional sleep aids or analgesics and looking towards THC for relief. The science on how cannabis affects these issues is still developing, but here is what we know so far
Chronic Pain – one of the leading causes of sleep-related issues in the world today is chronic pain and inflammation, affecting about 20% of adults. This is often associated with a range of issues such as rheumatoid arthritis, cancer treatment, immune disorders, and more. One group that is particularly affected by this are MS sufferers, who tend to have both chronic pain, sleep apnea, and other sleep issues. It has been found that taking CBD can reduce pain and inflammation, with users reporting better sleep. However, in studies using 1:1 CBD to THC tinctures and PSG indicators no benefits were found. The synthetic THC, Nabilone, has been shown in clinical trials to improve sleep in chronic pain patients. Although studies have found THC does not improve sleep quality, the fact that it is most commonly used by patients for the treatment of choric pain probably means that, indirectly, this is its most useful property regarding sleep.
Nightmares/PTSD- In individuals suffering from PTSD, nightmares are a very common source of insomnia, leading to decreased mental abilities, sleepiness, and an overall decrease in quality of life. THC has been shown to reduce REM sleep, leading to a decrease in nightmares, improving the quality of sleep for those suffering from PTSD. Although, it should be noted that more studies are needed to confirm the benefits and the long-term risks of heavy cannabis use in PTSD patients.
Sleep Apnea – Obstructive Sleep Apnea affects around 9% of Americans and is the most common form of sleep-disturbance due to breathing disorders. Studies in both rats and humans have shown that THC has therapeutic potential in the short-term treatment of sleep apnea, however, no long-term studies have been completed.
Opioid Use- one of the leading causes of accidental death in America today is due to prescription opioids, with America consuming around 70% of the world’s supply. Opioid use is very high amongst cancer patients, and sleep lab studies have shown that the long-term use of opioids actually lead to more pain disturbed sleep, prolonged time to falling asleep, and reduced the length of stages 3 and 4 sleep (deep sleep) and REM sleep; contributing to depression and even enhanced pain sensitivity. A 2017 study found that users of medical marijuana were able to reduce their dependency on opioids, anti-anxiety medications, sleep medications, and alcohol that are commonly used to aid sleeping. The effect was quite significant, with about 76% of opioid users reducing the number of pills taken. This has long term implications for the health and wellbeing of patients on these drugs.
Negative effects of cannabis on sleep
Several reviews and studies also pointed out the issues with cannabis use for sleep, most notably the decreases in sleep quality associated with long-term use, and difficulties sleeping following withdrawal from cannabis.
Although the short-term benefits of THC on sleep are well established, the long-term implications indicate the reason for concern. In sleep lab studies, long-term cannabis use was associated with decreased sleep quality in many of the same ways that alcohol affects sleep patterns. This has been attributed to a decrease in the expression of various sleep cycles necessary to maintain proper memory, cognitive function, wakefulness during the day, and ability to wake up in the morning. Users notice a decrease in the experience and memory of dreams, which has been explained by a reduction in REM sleep, which is vital to neurological wellbeing.
Cannabis withdrawal has been indicated to decrease sleep quality in many long-term users, including difficulties in falling or staying asleep, strange dreams, and insomnia in about 36 to 76 percent of people. Studies using PSG techniques have confirmed this loss of sleep quality, proving that it is not just a habitual response to cessation. These symptoms usually occurred for about 4-14 days, but in some patients lasted as long as 46 days, often causing those trying to quit cannabis to relapse. These conditions were found to be effectively controlled by taking the prescription sleep medication Zolpidem in one study, but that should only be used temporarily, as it also has negative long-term side effects and potential for dependence.
So, although the science of THC and sleep is still in its infancy, there are several take-home messages that the current literature indicates. The first is that the short-term use of THC increases sleep quality in healthy individuals, especially at small doses. Strains high in THC should be used for sleep, and those high in CBD are better suited for daytime to regulate wakefulness. For normal users, care should be taken not to develop a dependence on THC for sleep, but for those with medical conditions it can be an effective long-term treatment that reduces dependency on more dangerous and addictive synthetic drugs.