While there are still many questions to be answered, existing research suggests that the effects of cannabis on sleep may depend on many factors, including individual differences, cannabis concentrations and frequency of use.
Access to cannabis is increasing. As of last November, 28 U.S. states and the District of Columbia had legalized cannabis for medicinal purposes.
Research on the effects of cannabis on sleep in humans has largely been compiled of somewhat inconsistent studies conducted in the 1970s. Researchers seeking to learn how cannabis affects the sleeping brain have studied volunteers in the sleep laboratory and measured sleep stages and sleep continuity. Some studies showed that users’ ability to fall and stay asleep improved. A small number of subjects also had a slight increase in slow wave sleep, the deepest stage of sleep.
Over the past decade, research has focused more on the use of cannabis for medical purposes. Individuals with insomnia tend to use medical cannabis for sleep at a high rate. Up to 65 percent of former cannabis users identified poor sleep as a reason for relapsing. Use for sleep is particularly common in individuals with PTSD and pain.