New preliminary research, published in BMJ Supportive & Palliative Care, suggests that medical cannabis may not be an effective long-term treatment for chronic pain patients who report sleeping problems, as frequent users can build up a tolerance to the drug's sleep-promoting effects.
Cannabis use, frequency, and sleep
The new, observational study was led by researchers from the University of Haifa Faculty of Social Welfare and Health Sciences, with additional researchers involved from the Technion Israel Institute of Technology and Rambam Health Care Campus, in Haifa, Israel.
Researchers recruited 128 individuals with chronic pain, all over the age of 50, from the Rambam Institute for Pain Medicine. Of these participants, 66 were medical cannabis users, and all reported having experienced chronic pain that had lasted at least a year.
One in four (24 percent) of the study participants reported consistently waking up early and having trouble falling back asleep, and one in five (20 percent) said that they always found it difficult to fall asleep at night. Twenty-seven percent of the participants reported that is was common for them to wake up during the night.
Data gathered from the responses of the subset of participants that used medical cannabis revealed that, on average, they used the drug for around four years, consuming an average of 31 grams of cannabis per month. The vast majority (69 percent) reported smoking cannabis as their main consumption method, with a further 20 percent reporting the use of cannabis oils or cannabis vape products.
After adjusting for differences in age, sex, pain level, and use of sleep and anti-depressant medications, the researchers compared the difference in responses between the two groups of medical cannabis users and non-users.
The researchers found that medical cannabis use was generally associated with fewer problems waking up during the night, compared to non-use. There were no significant differences seen between the two groups in terms of problems falling asleep or waking up early.
Frequent users may build up a tolerance to beneficial effects
While the researchers observed medical cannabis to have an overall positive effect on promoting better sleep in chronic pain patients, the researchers believe that long-term frequent use can result in the buildup of tolerance to the sleep-promoting effects of the drug.
In fact, frequent medical cannabis use was associated with more problems waking up at night and falling asleep.
“This may signal the development of tolerance,” the researchers wrote in the paper. They also note that more frequent cannabis users may be suffering from greater levels of pain, or be depressed/anxious, and this could be the result of the additional sleep problems.
Due to the observational nature of the study, which relies on patient self-reporting, it cannot conclusively point to tolerance as the cause of these effects.
"These findings have large public health impacts considering the aging of the population, the relatively high prevalence of sleep problems in this population, along with the increasing use of medicinal cannabis,” the researchers concluded.
Dr David Meiri was one of the researchers involved in this new sleep study. Speaking to Analytical Cannabis in September last year, he promoted a more holistic view of cannabis treatment.
“If you look in very specific and narrow window on pain, you would say [cannabis is] not good. If you look how I think you should look on cannabis policy – more holistic and doing other things that are related to pain and depression, sleep, anxiety – now you're treating all of them and the patient is much, much better. If you look just to measure a very, very narrow question, then you will fail.”
