Most people forget their dreams shortly after waking. As soon as the eyelids flutter open, an entire evening of vivid adventures and abstract situations shuffle to an end, often leaving only lingering traces of their presence — a fragment of a dress here, the flashing face of a stranger there. While some individuals may be adept at remembering these mysterious nocturnal encounters, for the most part, the dreaming mind remains an enigma.
For those who consume cannabis, the dreaming self may remain even more elusive. The plant, you see, may prevent the sleeping mind from dreaming. Although cannabis has long been used as a meditation aid and sleep-inducer, preliminary research suggests the trance-inducing herb may suppress some forms of sleep consciousness. Of course, however, research on how cannabis affects dreams is far too premature to make any serious assessments.
The Purpose of Dreaming
Dream science over the past several decades provides more and more hints into the true nature of the dreaming mind. While the exact purpose of dreaming is unclear and dreams are particularly difficult to study, it is generally understood that the dreaming mind is also an emotional mind. While logic and rationality dominate during the day, the unique function of the dreaming mind is to help soothe and come to terms with emotional memories.
Most dreaming occurs during rapid eye movement sleep (REM sleep). The REM cycle is the closest sleep state to wakefulness when electrical activity in the brain increases, along with heart rate and breathing. During this time, levels of bodily stress hormones drop to their lowest levels. During the day, the hormone norepinephrine increased in the bloodstream in response to everyday stressors and anxieties. At night, however, norepinephrine levels slowly decrease as the dreaming mind takes over.
Brain scans suggest that the dreaming mind is very similar to the waking mind; visual areas of the brain are highly engaged, as well as areas related to memory and conscious thinking. A primary difference, however, is that the waking mind also responds to stress signals by releasing hormones like norepinephrine for fight-or-flight response. When dreaming, even strong emotions are distanced from this fight-or-flight impulse of the nervous system.
While the content of dreams may be very different than your visual memories from everyday life, it appears that emotional memory processing is a core function of REM sleep. The situations that your dreaming self is exposed to may be abstract or downright weird, but the emotional context of the dream may be what holds real value.
How Cannabis Affects Dreams
If dreams are the brain’s way of de-escalating and filing away emotional memories, then the effects of cannabis on dreams are well worth knowing. Thus far, a multitude of preclinical and small human trials show that cannabis consumption causes a reduction in REM sleep. This reduction is most strongly correlated with THC, although animal research thus far hasn’t determined whether or not the same effect occurs with CBD.
For individuals with recurring nightmares, this could be a positive benefit. Those with post-traumatic stress disorder (PTSD), for example, often demonstrate disturbed REM sleep patterns and may consistently remember their dreams. Healthy sleep is sleep that promotes feelings of restfulness upon waking. If a person plagued by chronic nightmares, it can have a distressing impact on the next wakeful day
In PTSD, patients are unable to delete fear-based experiences from their memories. Already, preclinical research suggests that cannabis medicines may be beneficial for those with the condition, potentially helping patients extinguish fear-based memories during the waking day.
And yet, for the everyday individual, the overall effect of cannabis on dreams remains unknown. Research suggests that the plant does, in fact, reduce dreams and limits the amount of time spent in REM sleep. Given that REM sleep is when the body records and desensitizes emotional memories, it’s possible that reducing time spent in REM may have a negative effect on emotional processing.
The catch? Very little research has been conducted on the aftermath of cannabis consumption on dreaming. Although cannabis is one of the most popular illicit sleep aids in the world, no high-quality or conclusive evidence exists on the impact of cannabis on sleep. Further, the bulk of research on the topic was conducted in the 1970s and 1980s, with isolated cannabis compounds and small participant numbers. As a result, the way in which cannabis affects dreaming and the implications this may have on waking life are simply unknown.
REM Rebound
The human brain does not like to go without enough REM sleep. While quality research on cannabis and dreaming is appallingly absent from the scientific literature, what is known, however, is that dreams come back with a vengeance after a brief period of abstinence from the plant. When regular cannabis consumers abstain from the herb, one of the most common side effects of withdrawal is the resurgence of very vivid and memorable dreams. This phenomenon has a proper name: REM rebound.
During REM rebound, a person is able to reach a state of REM sleep more quickly. They’re also more likely to remain in REM sleep for an extended amount of time. This dreaming rebound most often occurs after a person experiences sleep deprivation. The brain, it would seem, opens the floodgates of emotion once you’ve finally safe to hit the hay.
In terms of REM sleep, does cannabis produce similar effects to sleep deprivation? Without more research on how cannabis affects dreams, it’s hard to say.