Some issues regarding sleep may be due to those who use cannabis for its psychoactive effects. A study found that daily cannabis smokers had a higher score on the Insomnia Severity Index, a sleep-disturbance measure, than those not using it daily or the control group that never used it.
One of the most common reasons given by people who use cannabis daily is that they want to improve their sleep. Though, the study findings show occasional use doesn’t disrupt sleep, heavy use or daily use can be associated with sleep difficulties. The effect of daily use on sleep patterns seems to mimic that of alcohol use, in the sense that daily use worsens sleep while intermittent use improves sleep continuity. Neurologist and somnologist, Dr Hans Hamburger explains,
“By smoking weed, you suppress the REM sleep, and with that you also suppress a lot of important functions of that REM sleep. One of those functions is reliving the things you have experienced and coming to terms with them, as it were. Processing all kinds of psychological influences is something you do in REM sleep. You also anticipate the things that will happen the next day or the days after that. While you're sleeping, you already consider those and make decisions in advance."
So it would seem that intermittent use of cannabis may be a helpful sleep aid, but heavy cannabis users who take higher levels of THC than is found in industrial hemp can actually be subversive for sleep. CBD oil for sleep, though, has been found to positively influence the sleep cycle by increasing the third phase of sleep, which is the phase in which you are in deep sleep.
People who smoke cannabis often smoke it to get high and for its calming qualities, using cannabis specifically cultivated for very high amounts of THC content. Strains such as skunk are bred to contain as much of the psychoactive compound as possible, with THC levels increasing dramatically over the last few decades due to the popularity of THC’s effects for recreational users.
So it is important for those who use cannabis for sleep to understand that regular use of cannabis plants grown for their high THC content may be prompting further sleep difficulties, rather than aiding sleep.