A study published in the BMJ Supportive & Palliative Care suggests that long term medicinal cannabis patients may build a tolerance to the sleep-inducing effects often experienced from cannabis use.
Chronic pain is believed to affect around 19% to 37% of adults in the developed world and is often linked to poor sleep. Sufferers of chronic pain often find that they have trouble getting to sleep, staying asleep and waking up early.
In the study, researchers wanted to determine how medicinal cannabis could impact sleep problems in people aged over 50 who had been experiencing chronic pain for at least a year. All patients were treated at a specialist pain clinic, 66 were using medicinal cannabis to try and help their sleep problems, while the remaining 62 did not use cannabis. Researches measured the pain and sleep quality of the 128 participants using standardised point scoring systems.
66 of the patients had used medicinal cannabis for an average of 4 years, consuming around 31 grams a month. Most participants who used cannabis did so by smoking (69%), with another 20% vapourising cannabis or consuming cannabis oils/tinctures.
Researchers found that when they took into consideration other factors that could potentially influence the patient’s sleep, including; average pain score, age, gender, use of other sleep methods or antidepressants, medicinal cannabis users were less likely to wake during the night than non-users.
However, there were no recorded differences between the two groups in the time it took them to get to sleep, or how often they woke earlier.
In further analysis of sleep patterns of the group who used medicinal cannabis, it was found that frequency of use was actually associated with greater difficulty falling asleep, and waking more during the night.
Researchers suggest that this may signal the “development of tolerance”. They do however acknowledge that medicinal cannabis patients that do use more frequently may do so because they are in more pain, or be depressed/anxious, which may cause their sleep problems.
The drawbacks of the study are the small number of participants, and because it is an observational study no cause can be determined. Also, there were no details provided for the time of day medicinal cannabis was consumed.
The researchers added, ”These findings have large public health impacts considering the ageing of the population, the relatively high prevalence of sleep problems in this population, along with the increasing use of medicinal cannabis.”