U.S, April 21, 2020 (ANALYTICALCANNABIS) Insomnia is one of the most common sleep disorders in the world. Its prevalence sits between 10-to-30 percent in the general population and climbs as high as 50-to-60 percent for older adults and people with medical or mental ill health.
People with insomnia find it difficult to fall and remain asleep, often to the point where it affects their ability to function in day-to-day life. Its daytime consequences can include fatigue, impaired concentration, memory problems, social dysfunction, and mood disturbances. Insomnia has also been associated with several other chronic health problems, such as heart disease, endocrine dysfunction, and hypertension.
Many casual users of cannabis and CBD products report that the drug is able to effectively disperse their feelings of stress and anxiety, allowing them to relax more completely and sleep more easily through the night.
In a recent survey of 1,000 recreational cannabis customers in Colorado, 84 percent of respondents said that they found cannabis to be “very or extremely helpful,” and a significant portion chose to reduce their use of other sleep aids in favor of the drug.
So, can cannabis really improve sleep so dramatically?
Cannabis for sleep
Looking at the application of medical cannabis in treating insomnia, one 2018 study concluded that medical cannabis consumption “is associated with significant improvements in perceived insomnia with differential effectiveness and side effect profiles, depending on the product characteristics.”
The study used data submitted by 409 people with insomnia via an app, which recorded real-time ratings of perceived insomnia severity prior to and following cannabis consumption. The study found that, on average, users reported an average of a 4.5 point reduction on a 0-10 scale of symptom severity after using cannabis, and that vaporizer use and higher cannabidiol (CBD) contents were associated with greater symptom relief.
In a 2019 review, this time focusing on the use of cannabis in treating symptoms of post-traumatic stress disorder (PTSD), researchers found that cannabis products did appear to reduce PTSD-relate insomnia and nightmares. However, the researchers also noted that “most studies to date are small and of low quality, with significant limitations to the study design,” and so further studies must be carried out before endorsing clinical use.
Tetrahydrocannabinol (THC), the major intoxicating compound present in cannabis, has also been linked to general improvements in sleep quality. A 2008 study found that both smoked cannabis and orally administered THC reduces the amount of REM sleep each night, while increasing the proportion of time spent in stage 4 sleep, the deepest level of sleep. Additionally, the researchers found that acute administration of cannabis also appeared to facilitate falling asleep at night. However, it should be noted that getting too little REM sleep can also be problematic, and can lead to memory problems and mood disorders in some people.
Cannabis as a sleep disturbance
While it’s clear that cannabis does have an effect on sleep, it’s not so clear cut whether that effect is positive or negative. In addition to the studies listed above, there are also several that link cannabis to worse sleep outcomes.
According to a literature review from 2017, preliminary research would indicate that CBD may have therapeutic potential in treating insomnia and THC may decrease sleep latency. However, the review also found that THC may impair sleep in the long-term and CBD could act as a stimulant in high enough doses.
This is consistent with a more recent 2019 study, which concluded that medical cannabis may not be an effective treatment for chronic pain patients with symptoms of insomnia, as frequent users can build up a tolerance to cannabis’ sleep-promoting effects. In fact, frequent medical cannabis use in this study was actually associated with more problems falling asleep and waking up at night.
Marijuana and sleep – is there a genetic basis?
A new study from researchers at the University of Colorado offers another look at the associations between cannabis use and sleeping problems. While cannabis use has been linked to causing long-term sleep problems, the researchers also note that adolescent insomnia has also been linked to a greater likelihood of using cannabis.
“With longitudinal evidence in both directions, it is possible that sleep problems could influence cannabis use, cannabis use could influence sleep problems, or an underlying shared liability such as common genetics could be responsible for their association,” the researchers hypothesized.
The researchers surveyed 1882 individual twins from Colorado, who were questioned on their substance use and their sleeping habits on weekdays. Controlling for sex, current depression symptoms, and prior diagnoses of depression and anxiety, the researchers confirmed that early onset of cannabis use (defined as before 17 years of age) was associated with an increased rate of young adult insomnia.
The researchers also observed both genetic and non-shared environmental contributions to the causation of early onset cannabis use, insomnia, and insomnia with short sleep. This is the first instance reporting a genetic contribution to insomnia with short sleep on weekdays, according to the researchers.
“Our results suggest that the relationship of onset of regular cannabis use with insomnia and insomnia with short sleep on weekdays may also be due to pleiotropic influence of genes on these traits,” the researchers wrote.
The endocannabinoid system may play a large part in this relationship, the scientists hypothesized, as some genome-wide association studies (GWAS) have tied cannabinoid activity to sleep-related variables, such as insomnia and sleep duration.
The researchers also suggested that genes related to circadian rhythm and sleep could play an important role; other GWASs that investigated life-time cannabis use have found significant genes associated with circadian rhythm and other sleep behaviors.
Further research is needed to fully understand the potential developmental impact of early regular cannabis use on adult sleep, specifically on clinically important outcomes such as insomnia, the researchers noted. Further research should also continue to consider the role of genetics in the relationship between early cannabis use and sleep.