We humans are fascinated by dreams. Think about it: how many times has someone struck up a conversation with you – whether a family member around the breakfast table or a colleague in the office – seemingly itching to tell you about their “weird” dream? Even those of us who aren’t particularly interested in hearing about the dreams of others have more likely than not exposed our friends, family, and colleagues to similar anecdotes. So, whether you are the kind of person who simply shakes off a dream as soon as you wake from your slumber or the type to spend hours researching its meaning, there is no denying that dreams remain a topic of significant interest in most – if not all – societies around the world.

“But how is this relevant to cannabis?”, I hear you ask. Well, you may have heard contrasting reports on how cannabis consumption affects your dreams. Does it make you have increasingly bizarre dreams the more you smoke? Or does it stop you from dreaming altogether? We’re taking a look at the research and evidence so far to better understand how cannabis use affects our dreams.

Cannabis and sleep

For many consumers – whether recreational or medicinal – cannabis is an important part of their night-time routine. This may simply be because it is the most convenient and less disruptive time to partake. On the other hand, some people may use cannabis at night specifically to help them to get to sleep. A number of studies have concluded that cannabis can help to induce sleep and even improve sleep quality.

For example, in one study of people with insomnia and other sleep disorders, 71% of participants reported a subjective improvement in their sleep or condition after initiating medical cannabis treatment. But cannabis hasn’t only proven useful in sleep conditions. A multitude of studies that focused on various other conditions, from depression to inflammatory bowel disease, have also found that cannabis had a secondary benefit on sleep quality. People with conditions for which pain is a major symptom may also report that cannabis helps them to get to sleep.

On the other hand, other studies have suggested that this potential benefit may be short-lived. But enough about sleeping – what about dreaming?

Why do we dream?

While some dreams can seem to last a lifetime, they can actually only occur within a specific window in our sleep. This is known as Rapid Eye Movement or “REM” sleep. This period of the sleep cycle occurs approximately 90 minutes into our sleep and, for the average person, makes up only around 20-25% of our total sleep. REM sleep is activated by the release of acetylcholine – a neurotransmitter found in the brains and bodies of many animals – and other chemical activity in the “pons” region of the brain stem. During REM sleep, there is also a notable absence of some other neurotransmitters, including histamine, norepinephrine, and serotonin.

The truth is, we still don’t know exactly why we dream – but there are a number of interesting theories: some scientists believe that dreaming helps us to consolidate memories or process our emotions while others think it has more to do with expressing our sub-conscious desires or preparing ourselves for facing potential dangers. Whatever the reason, our dreams can be incredibly diverse, ranging from the terrifying to the whimsical to the outright bizarre. So, how does cannabis – if at all – influence our dreams?

The link between cannabis and dreams

Various sources, including a 2019 study by researchers from Swansea University, suggest that cannabis can suppress REM sleep. The study monitored both cannabis users and non-users, asking them to report on their dreams at regular intervals in the night and upon waking in the morning. They found that, while users and non-users reported no significant differences in sleep quality, cannabis users demonstrated significantly longer sleep latency and less REM sleep overall. Interestingly, cannabis users also reported “higher bizarreness” in their dreams.

Another study also identified a lower occurrence of REM sleep in cannabis users. This may explain, then, why many cannabis users report that they dream very little, and even not at all. Nonetheless, the actual reason for this effect is still not fully understood. But this suppression of REM sleep – and potentially of dreaming – can apparently have a negative effect.

According to Dr. Rubin Naimen, an expert from the University of Arizona’s Center for Integrative Medicine, we are in the midst of an epidemic of REM sleep deprivation. As it turns out, REM sleep is actually very important for memory consolidation, and those of us that don’t get enough of it may well be at risk of leaving a lot of what we learn throughout the day unprocessed. And it isn’t just cannabis that can affect our levels of REM sleep. Other drugs, including alcohol and tobacco, have also been found to reduce REM sleep.

However, some people speculate that – for some people – the absence of dreams might actually be a good thing.

Cannabis, anxiety, and PTSD

A number of anxiety conditions, including post-traumatic stress disorder (PTSD), can often be associated with the occurrence of nightmares. These dreams can be traumatic and triggering for the individuals experiencing them, and result in the worsening of other symptoms. Therefore, it has been theorised that the apparent dream-suppressing quality of cannabis could be a potential solution. As a 2019 editorial found, both THC and nabilone (a synthetic analogue of THC) have been found to reduce the frequency of nightmares and improve other PTSD-related symptoms.

While these findings offer a promising route for investigation and the potential development of useful treatment options, more research is needed to fully understand the links between cannabis use and PTSD. Similarly, as with most aspects of cannabis research, our understanding of how cannabis affects REM sleep and dreaming still remains significantly underdeveloped. 

Your dreams after taking a break from cannabis

The good news (hopefully) is that the potential loss of dreams triggered by regular cannabis use is reversible. However, you may get more than you bargained for. Many anecdotal reports suggest that taking a break from cannabis can make your dreams come back – in a big way. This is likely due to the sudden re-ignition of your REM sleep cycle, resulting in more vivid and intense dreams. While this might seem like a positive, some people also report a higher frequency of nightmares during this time – so it’s up to you to draw a conclusion on the benefits…