Medicinal and recreational advocates have long loved the mildly sedative, sleep-promoting qualities of cannabis, but what does the research actually show us? Stoner stereotypes aside, cannabis has a lengthy history as a sleepy plant-companion. Its sedative properties were noted 150 years ago, in early scientific literature, by William Brooke O’Shaughnessy, the Irish physician responsible for introducing cannabis Sativa to Western medicine. Today, sleep scientists continue to target the plant as a possible all-natural alternative sleep aid.
With several decades of sleep research to build on, cannabis for insomnia and sleep remains a popular area of study. Several different cannabinoids seem to play a role in regulating sleep, from the sedative qualities of THC to the dose-dependent regulation of CBD. Researchers now have a much better idea of how cannabinoids help patients get to sleep and stay asleep. There is also a better idea of how long-term use could turn a positive result into a problematic one.
In this first piece on medical cannabis for sleep, we’ll look at the research on the benefits of cannabis for various sleep disorders, including those related to medical conditions like post traumatic stress disorder (PTSD), Parkinson’s disease, and pain. Later in February, we will explore the issues researchers have uncovered about how heavy, long-term cannabis use may negatively affect sleep quality.
How Cannabis and Cannabinoids Impact Sleep
There is a two-way relationship between sleep and the endocannabinoid system. First, sleep directly impacts the healthy functioning of the endocannabinoid system. Second, this system is responsible for the regulation of the sleep-wake cycle of the circadian rhythm. Healthy, normal sleep plays into a healthy and functional endocannabinoid system and vice versa.
With the growing evidence behind this interconnected sleep-endocannabinoid relationship, logically, cannabinoids should influence sleep as well. Cannabinoids, natural compounds found in all varieties of cannabis, seamlessly interact with the endocannabinoid system to affect mood, memory, pain, appetite, inflammation, and also sleep.
By now, there are several critical and systematic reviews published about the nuanced relationship between cannabis and sleep. Beyond the anecdotal reports of cannabis advocates and patients, there is a growing understanding of the therapeutic value this plant may have as a sleep aid.
Long-term cannabis use aside for the moment, “Cannabis, Cannabinoids, and Sleep: a Review of the Literature,” a 2017 literature review, concluded, “Taken together, research suggests that short-term use of cannabis may have a therapeutic impact on sleep, specifically related to sleep onset latency and slow wave sleep.”
Sleep Disturbances Related to Pain
The BMJ Supportive & Palliative Care published “Medical cannabis and insomnia in older adults with chronic pain: a cross-sectional study” in early 2020. The goal of the study was to determine why pain patients tended to prefer whole-plant cannabis to overcome insomnia, compared with pharmaceutical sleep-aids.
The study consisted of 128 patients, all recruited from a pain clinic in Haifa, Israel. Approximately half of the group were already medical cannabis users, and the other half were not. The team of researchers, led by Sharon Sznitman, compared the sleep problems between the two groups of patients.
After controlling for gender, age, pain level, and antidepressant medications, the Israeli-based team of researchers confirmed that the medical cannabis group experienced fewer problems waking up at night, compared with the control group. Cannabis improved the problems patients had waking up at night but notably didn’t have an impact on how long it took to fall asleep. The authors noted frequent (meaning chronic) cannabis consumption had a negative, dose-dependent effect on sleep.
Sleep Disturbances Related to Parkinson’s Disease
Several small studies and case reports have detailed the positive impact of cannabinoids for the treatment of Parkinson’s disease, in particular the ability to improve sleep. Parkinson’s disease is typically characterized by progressively severe neurological degeneration, including sleep-related symptoms like restless legs, sleep talking, vivid dreaming, and difficulties falling and staying asleep.
According to a 2015 paper, “Self-Reported Efficacy of Cannabis and Other Complementary Medicine Modalities by Parkinson’s Disease Patients in Colorado,” some patients reported significant benefits to sleep following medical cannabis use. More than 75 percent of the survey respondents in this study detailed positive benefits to sleep following cannabis use. Although the group was small, the report paves the way for future research on the subject.
A year earlier, in the Journal of Clinical Neuropharmacology, another Israel-based team of scientists at Tel Aviv University discovered cannabis also improved sleep scores among a group of patients with Parkinson’s disease. Their open-label observational study used several assessments (including the Unified Parkinson Disease Rating Scale, visual analog scale, and the Short-Form McGill Pain Questionnaire) 30 minutes after patients used medical cannabis. Although not a primary goal of the initial study, the authors concluded, “There was also significant improvement of sleep and pain scores,” and importantly, they recorded no adverse effects.
Sleep Disturbances Related to PTSD
Another area of cannabis research getting a lot of attention these days is the impact the plant may have for symptoms of PTSD, particularly the effects on sleep disturbances. There have already been scientific explorations into how cannabinoids (in the form of nabilone) improve sleep disturbances for military service members and prison inmates with PTSD. Cannabis seems most valuable for its ability to suppress distressing and disturbing nightmares experienced by those with PTSD.
Published in 2014, “Using cannabis to help you sleep: Heightened frequency of medical cannabis use among those with PTSD” determined that people with high PTSD scores were more likely to rely on cannabis than those with low scores. Of the 170 patients who reported to the study, the primary motivation for cannabis use was to improve sleep.
A literature review from2015 examined research on patients using cannabis to cope with the symptoms of PTSD. Authors Kevin Betthauser, Jeffery Pilz, and Laura Vollmert discovered that “[t]he Data from 4 small studies suggested that cannabinoid use was associated with global improvements in PTSD symptoms or amelioration of specific PTSD symptoms such as insomnia and nightmares.”
Cannabinoids Benefit Sleep for Specific Medical Conditions
As with nearly all areas of cannabis research, there is a dire need for further well-controlled studies on sleep. At the time of writing, most research supports a dose-dependent and short-term benefit for patients, with both THC and CBD. The most benefits may come from improving the quality of sleep and reducing nighttime sleep-disruptions.
There is also a growing scientific basis for cannabis use among patients with medical conditions characterized by nighttime restlessness and sleep disturbances. Patients with PTSD and chronic pain often report preferring cannabis as a sleep aid when compared to other options, like conventional pharmaceuticals.
Although patients and cannabis proponents have been relying on the plant’s sleep-promoting qualities for decades (if not centuries), we are only now starting to understand its biological mechanisms. It will be several more years before scientists iron out the specifics on dose, cannabinoid profile, and duration to perfect this plant-based sleep aid.