Why Cannabis Can Make You Feel Anxious

[This article refers to cannabis that is smoked or vaporized, NOT ingested. Ingesting (edibles) cannabis produces 11-hydroxy-THC in the liver which is more bioavailable than THC and WILL get you substantially more intoxicated and for much longer.]

Most of us have either heard a story or experienced it ourselves; you smoked some (or a lot) weed and now you are feeling anxious and uneasy. You wanted to chill out but now you are paying attention to little details, making you question yourself. 

This can be a troubling side-effect to something we see promoted as an aide for relaxing and chilling out. How is that something Snoop Dogg can practically live off of can make your friend Jessica totally freak out?

To begin to understand how and why cannabis can elicit this anxiety we need to understand how cannabis works in our bodies to get us “high”, and that starts with something called cannabinoids. 

Anandamide & Cannabinoids


These are naturally occurring compounds found in cannabis (and our bodies), thought to have evolved in cannabis for a variety of reasons, some including defending against insects, frost, water loss, ultraviolet light, overheating and attracting pollinators or dissuading prey. 

When ingested by creatures like ourselves, these compounds interact with receptor sites in our brain and body, receptors that play important roles in transmitting information regarding our bodily functions, memory, pain, mood and appetite. 

In our bodies anandamide is the molecule we produce to activate those receptor sites. THC looks so similar that our bodies accept the molecule into that same receptor site to relay it’s message. 

The two most well known cannabinoids are THC and CBD, the former being the intoxicating one. CBD however is non-psychotropic, doesn’t get you high and is present in high quantities in hemp, the fibrous twin of cannabis with only trace amounts of THC. 

So THC binds to the cannabinoid receptors in our brains, thereby releasing the neurotransmitters dopamine, serotonin, and GABA. These three neurotransmitters play a crucial role in our development of drugs that treat depression, anxiety and other psychiatric disorders. 

Brain & Hormone Sensitivity

Boy and Girl Cutout Decals

However, increasing those neurotransmitters can also decrease another one called norepinephrine. For some people this means increased anxiety because of their unique brain’s reaction to a reduction in that neurotransmitter. 

We know that specific brain regions responsible for producing the feelings we experience from consuming cannabis also vary slightly in everybody’s brain. 

These differences, influenced by individual genetics, might lead some to feeling a rush of euphoria while leaving others with an uneasy, panic-stricken feeling from the same strain and THC amount.

Some people even produce more of a certain hormone called pregnenolone that acts as a natural neutralizer of THC, allowing them to adjust quicker after consuming cannabis. And even then, differences in individual metabolism may contribute to whether the high is felt as strong or weak.

Individual Genetics

DNA | New Scientist

Much of what we learn concerning how our bodies and brains will react to specific compounds comes from animal studies. 

One such study found cannabis can produce the positive effects we all enjoy when providing more stimulation to frontal brain regions. The authors suggest that this has to do with large numbers of opioid receptors present there. 

They then hypothesize that those prone to cannabis induced anxiety might have a higher sensitivity to THC in their posterior brain region (back part), known to be the seat of your fight or flight response. 

A researcher from the University of Western Ontario study stated in a release, “Our data indicate that because the reward and aversion are produced by anatomically distinct areas, the different effects between individuals is likely due to genetic variation leading to differential sensitivity of each area.”

Dose Dependence & Sex

Research from The University of Illinois found more interesting factors contributing to cannabis related anxiety. 

The study looked at 42 healthy adults consuming 2 varying doses of THC and then committing to a slightly stressful task. The researchers found that those consuming 7.5mg’s of THC reduced the negative feelings associated with the task, and those consuming a higher dose of 12.5mg’s had the opposite effect.

Another study found higher levels of estrogen can increase a person’s sensitivity to THC, meaning many female’s tolerance levels could be up to as much as 30% lower, increasing both the positive and negative (anxiety) effects. 

Vulnerable Users Beware

Person Leaning on Wall

The largest study ever conducted on the link between paranoia and cannabis in vulnerable individuals (those who reported having paranoid thoughts in the last month – typically half a given population as stated by the researchers) found THC caused paranoid thoughts by shifting the individual’s mood and view of the self.

As stated by Daniel Freeman and Jason Freeman their blog article Cannabis really can trigger paranoia – “THC also produced other unsettling psychological effects, such as anxiety, worry, lowered mood, and negative thoughts about the self. 

Short-term memory was impaired. And the THC sparked a range of what psychologists call “anomalous experiences”: sounds seemed louder than usual and colours brighter; thoughts appeared to echo in the individuals’ minds; and time seemed to be distorted.”

These effects wore off however as THC left the bloodstream, which takes up to 3-4 hours when smoked.

The Neuroscience of “Freaking Out”

The recent scientific discovery of the “salience network” in the brain gives us even more insight into why exactly some people experience intense paranoia under the influence of THC from a neurological perspective. 

This “salience network” in the brain is a network of neurons thought to be responsible for attributing values to our perceptions, helping us focus and respond to our environment, and the disruption of this network can lead to intense experiences of anxiety and paranoia

When ingesting too much THC and thereby disturbing the network, innocent glances from others while walking down the street or sitting at a restaurant suddenly become suspicious glares, leading to the inevitable conspiratorial proclamation “everyone is looking at me and knows I’m high!”. 


We hope this information helps you be more aware of the pitfalls and hurdles one must navigate when wanting to avoid potential anxiety or “freak-out” episodes when consuming cannabis. 

When in doubt we recommend taking it slow with a smaller amount of THC and pairing it with terpenes and CBD that might help modulate the effects towards a less anxious high.