Medical cannabis patients may have a tricky side effect to overcome: tolerance. A recent study from the Rambam Institute for Pain Medicine in Haifa, Israel found that pain patients may develop tolerance to the sleep-inducing effects of cannabis over time, making it harder for patients to fall asleep over the long term.
Medical Cannabis and Sleep
Medical cannabis patients often have chronic diseases that interfere with their ability to get restful sleep, pain among them. Pain is one of the most common reasons patients try medical cannabis, with two-thirds of patients using the plant to manage their chronic pain.
In the study, researchers discovered that cannabis patients were less likely to wake up during the night than their non-consuming counterparts.
But, there’s a catch.
The efficacy of cannabis as a sleep aid may depend on how often the herb is consumed, how long the patient’s been consuming it, and how much they’re taking. The more cannabis the patients consumed, the study suggests, the more likely the consumer experienced difficulty falling asleep and difficulty staying asleep.
The study was a small one, following 66 cannabis patients at a specialized pain clinic. These patients were compared to 62 of their non-consuming counterparts on three different factors: difficulties falling asleep, staying asleep, and waking up too early.
All of the consuming participants in the study used the herb for an average of four years, and all patients were over the age of 50.
But, while medical cannabis consumers faired better on sleep scales overall, this potential benefit appears to change as patients increase the amount of cannabis they consume.
Cannabis Tolerance and Sleep
The difference in sleep quality “may signal the development of tolerance,” the researchers suggest. Although, the study authors were quick to admit that the patients who took cannabis more frequently might also be in greater amounts of pain, which is more likely to affect their sleep.
Tolerance develops when consumers lose sensitivity to the effects of cannabis compounds. In early cellular studies, scientists observed that the cell receptors that respond to cannabis compounds—called cannabinoid receptors—temporarily stop responding to these same compounds after consuming high doses of the herb for extended periods of time. (Other experimental research suggests that these receptors begin to regain sensitivity in as little as two days after abstinence.)
In some cases, losing sensitivity to the plant can be beneficial. For example, many cannabis patients have difficultly with the intoxicating side effects of THC when first beginning medical cannabis treatments. Over time, however, these side effects decrease as tolerance develops.
Cannabis care providers may experience a trade-off, however. While tolerance may be desirable in some cases, tolerance may also cause the patient to lose sensitivity to the therapeutic effects that are most desirable, like quality sleep. This trade-off may be especially important to consider among aging patients, as sleep quality tends to decline with age.
While this small observational study is far from authoritative, it may be worthwhile for care providers to continue to assess sleep quality in long-term cannabis patients.
This study was published in BMJ Supportive and Palliative Care.