We spend more than 25% of our lives in bed, asleep. Sometimes, sleep can seem like an inconvenience in our busy and hectic lives. But without it, we would be in a horrible state. Many of the substances we take can affect the quality of our sleep. We all know that a cup of coffee will make sleep more difficult and a cup of valerian tea will add a touch of sedation. When it comes to cannabis, users report different effects.
Although cannabis seems to help people fall asleep, the plant can disrupt the normal sleep cycle. Many cannabis enthusiasts report that they dream less when smoking frequently, and little research suggests that THC reduces REM sleep.
Let’s take a closer look at the nature of sleep and how cannabis fits into it.
The effects of cannabis on the REM phase
Anecdotally, cannabis users tend not to dream when they use it extensively. There is not much research that explains why this can happen; scientists have only taken a brief dive into the subject.
A study conducted in 1974 and published in the journal Psychopharmacologia involved a small sample of five volunteers who slept in a laboratory for 8-15 consecutive nights. Each subject received a dose of 20 mg of THC before sleep. The researchers monitored their brain activity and eye movements throughout the night and eventually found that THC decreased the time spent in REM sleep. The researchers also tested the withdrawal effects of THC for 4-6 consecutive nights. Subjects had mild insomnia and there was no marked recovery from REM sleep.
One year later, a supportive study showed similar results. Researchers recorded the brain activity and rapid eye movements of experienced cannabis users who received either THC or placebo. The researchers found that THC administration significantly reduced eye movements during REM sleep. There was also a decrease in the duration of REM sleep. During the withdrawal phase, eye movements and REM sleep duration increased. Apart from the impact of THC on REM sleep, the study also showed that sleep duration in stage 4 increased with THC. The same stage of sleep decreased during weaning, but only during the first night.
Several other studies conducted around the same time have shown similar results, but the jury is still out. Better quality research using larger sample sizes and administration of full-spectrum extracts would increase reliability. For these reasons, the evidence remains inconclusive.
Dr. Timothy Roehrs, a sleep researcher, commented on the issue, saying: The literature on whether or not cannabis affects REM sleep is extremely weak and equivocal,” adding: “Some studies have shown that it suppresses REM sleep, some studies have shown that it does not.
He also says that he and a colleague at Wayne State University School of Medicine have found evidence that contradicts the popular view that cannabis suppresses REM sleep.
In the design of the study that was done, cannabis was smoked in the morning and afternoon, and some days it was active cannabis, and other days it was a placebo [with] 0.4 % THC or something like that,” he says. The active cannabis used in the study contained about 3 % THC.
Roehrs says there was no difference in the amount of REM sleep in patients who smoked active cannabis or placebo.
Does Cannabis prevent dreaming ?
There is no clear answer to this question at this time. Based on limited research, THC appears to affect brain activity and eye movement, which means a reduction in REM sleep duration. However, more recent research by Roehrs contradicts these findings.
Anecdotal evidence reports a reduction in dreaming after heavy cannabis use. Combined with older research, this makes it plausible that THC reduces REM sleep in some people. It is likely that THC – and cannabis as a whole – affects different people in different ways. It is a chemically complex plant, and each variety has different levels of cannabinoids and terpenes that can affect sleep. Besides, variables