Cannabis appears to help induce sleep but it does not seem to promote sleep continuity, according to new preliminary research published in the journal Drug and Alcohol Dependence.

“Cannabis use (medical and recreational use) probably has an impact on sleep but the research is very limited. It is theoretically possible that cannabis may both have positive and negative effects on sleep,” said study author Sharon Sznitman, a senior lecturer at the University of Haifa School of Public Health.

“There is an increase in people using cannabis and on top of that we have an ongoing epidemic of sleep problems in the general population. The combination of these factors make me extremely motivated to conduct research into the effects that cannabis has on sleep. My hope is that my research can help improve sleep in the general population and thereby improve public health.”

The researchers asked 54 regular cannabis users to complete a survey via their smartphones each morning for 7 consecutive days. The survey collected data such as the number of minutes it took to fall asleep the previous night, the number of times participants’ woke up, at what time participants’ used cannabis the previous evening, and at what time they fell asleep.

A shorter time between cannabis use and sleep start time was linked to falling asleep faster. However, it was not associated with less nightly awakenings. In other words, those who used cannabis right before bedtime tended to report that it took a shorter amount of time to fall asleep, but there was no evidence that they woke up less frequently in the middle of the night.

The findings indicate that “while it is possible that cannabis induces sleep it may not help maintain sleep. Pending further evidence of the effects of cannabis on sleep, cannabis users with sleep problems should be provided with evidence-based alternatives to improve sleep, e.g., pharmacological and behavioral treatments,” Sznitman told PsyPost.

The study provides some new insights into the relationship between sleep and cannabis use. But there is still much that is unknown.

“We do not know if there are sleep inducing effects that are reduced upon long term and/or heavy use. We do not know if the effects of cannabis on sleep are better than other more conventional and evidence-based treatment options. We also do not know if there are specific types of cannabis strains or cannabinoids that are particularly helpful or harmful for sleep. These and many other questions need to be answered before we can begin to potentially promote cannabis as a sleep aid,” Sznitman explained.

“I think it is very important for the general public to understand that despite a lot of media attention to the sleep inducing effects of cannabis, we have very little research that examines this. Cannabis may have important effects on sleep. These may be beneficial (and my current research are suggestive of sleep inducing effects) as well as detrimental depending on type of use.”

“It is, for instance, possible that people who use cannabis (for medical or recreational purposes) long term may develop tolerance to the sleep inducing effects. Pending further evidence of the effects of cannabis on sleep, people with sleep problems should be provided with evidence-based alternatives to improve sleep, e.g., pharmacological and behavioral treatments,” Sznitman said.

The study, “Is time elapsed between cannabis use and sleep start time associated with sleep continuity? An experience sampling method“, was authored by Sharon R. Sznitman, Tamar Shochat, and Talya Greene.