Sleep is one of the many areas where we see medical benefits with cannabis, and it’s one of the most common reasons people use the drug in Canada. Research by the Sleep Foundation found that around 70% of young people who use cannabis report doing so to help with sleep.
Cannabis tends to have a calming and mellowing onset, making it conducive for sleep. But how effective is cannabis really for sleep? What does the evidence say?
People tend to associate falling asleep fast as a metric for sleeping well, which is what happens when you consume cannabis. However, it is important to take the quality and nature of the sleep into consideration. Alcohol is a great example of this – you fall asleep quickly after consuming it, but overall it makes sleep worse. The quality of sleep with cannabis is a little more difficult to determine with mixed findings and a limited amount of research.
One study examined a sample of 21,000 individuals that consume cannabis for sleep. These individuals were more likely to have extremes of sleep duration – 64% were more likely than non-users to sleep less than 6 hours a night, and 76% more likely to sleep longer than 9 hours a night. This would suggest that cannabis users either get more or less sleep than is recommended.
Some research suggests that habitual cannabis users are more likely to suffer from insomnia and sleep problems. Studying heavy cannabis users, measures of greater sleep disturbance have been detected compared to a control group. So, although cannabis helps people fall asleep faster, it may impair sleep quality and throw off sleep cycles.
A study published in 2021 looked to determine the relationship between cannabis use and the subjective expectations of it as a sleep aid in 152 moderate cannabis users. The frequency of use and concentration of THC and CBD were not associated with sleep outcomes. The cohort also had increased expectations of cannabis being a sleep aid and found that over three quarters of participants thought they slept better thanks to cannabis.
Survey studies like this do have their limitations when it comes to reliable results. Especially as it is a self-selecting sample of people that have decided to use cannabis to help with sleep. Thus, they may have other factors affecting the quality of their sleep. Unfortunately like with any cannabis studies, there are a limited number of high quality randomised controlled trials (RCTs) that look at sleep.
A meta-analysis published in 2022 looked at 39 RCTs with a combined total of 5,100 patients. 33 of the studies used patients with chronic pain. From the combined research, 8% of patients saw benefits from cannabis use. As participants were from a population sample where cannabis is already linked to benefits and pain relief, sleep improvements might be an additional benefit that is more effective in this population specifically. It’s also possible that chronic pain patients experience more significant sleep problems than the general public, making it more difficult to treat generally.
Research does suggest that patients with sleep disorders, chronic conditions and mental health issues have better sleep outcomes with cannabis. Again, it might be the case that cannabis is helping with other symptoms that these patient populations are experiencing and sleep is an ancillary benefit that helps them get to bed in the initially with a range of other symptoms impacting on their ability to fall asleep, i.e. pain.
There is optimism around emerging research showing benefits of cannabis for sleep. There is plenty of anecdotal evidence suggesting it works for patients too. However, there is very little data comparing smoking cannabis to ingesting edibles or other forms of administration. It’s important that this needs to be better understood as it may be that a certain dose delivered in a certain way is what helps people sleep better.
A 2022 poll found that 14% of US adults say they use cannabis edibles and they do so for sleep. The evidence is still a little mixed. One study found that teenagers using edibles were more likely to get inadequate sleep. I would say this is far from the ideal sample to be studying as this research should really only look at adults.
Other research has found promising results. A review found that oral cannabis use helped those with chronic pain and anxiety. As edibles have a longer lasting and slow release effect to smoking, this might be why they could work better for sleep.
Clearly the research around cannabis and sleep is a bit of a mixed bag. This isn’t to say that cannabis doesn’t help sleep, the relationship might just be less clear cut with not enough research yet. One thing we know very little about are the long term effects of cannabis and sleep – studies have only looked at a timespan of around 35 days.
Overall, it may be the case that we should take the efficacy of cannabis on sleep with a pinch of salt – this really isn’t that different to other sleep medications though, as the biggest factor in effectiveness is belief.
Katya Kowalski is Head of Operations at Volteface. X @KowalskiKatya.