Author Archives: Janet Maia Martin

Does Marijuana REALLY relieve stress?

Hello everyone! I’m back (:

Well, this is now the end of my fourth week in Paris. There’s only one more week left, HOLY COW! Since I’ve been here, I think I have pretty much adjusted to the culture. I still smile when I see strangers, but I’ve just accepted the fact that they probably will not smile back.

However, there is one part of the culture I haven’t quite adjusted to yet… SMOKING! I heard before traveling here that smoking cigarettes is very common in Paris, and these rumors were not false. In Paris, you will literally see people smoking absolutely anywhere… at the train station, sitting at a restaurant, and I have even seen workers smoking while on duty. In America, smoking is much more moderated. There are designated areas for smoking and non-smoking. Here, smoking is the norm. I am pretty sure I have not seen one “non-smoking” sign since I have been here.

I expected that majority of people would smoke cigarettes, which is true. However, I was surprised by the vast amount of people I have seen smoking marijuana. I have seen multiple people on the train rolling up a joint, or even people walking down the street smoking it with no concerns whatsoever.

One day, a couple of my friends and I decided to head out for dinner. We were going to get Thai food at some restaurant we found on google (yep, still an avid google user).

As we were looking for the restaurant, the navigation led us down some weird side street. On  that street, we walked past a group of young girls sitting on the porch SMOKING MARIJUANA. Honestly, the girls looked no more than 13-14 years old. I was completely shocked. It was basically babies smoking weed.

The babies smoking on the porch. (Not actually, but this is how I perceived it.)

Okay, so this got me thinking. I knew marijuana had become increasingly prevalent in America just from my own experience. Marijuana references can be found all over social media, in music, television… it has really become a major part of pop culture. If you don’t want to take my word for it, The National Institute on Drug Abuse reports that, “Marijuana is the most commonly used illicit drug (22.2 million people have used it in the past month).” They also state that marijuana use is widespread among adolescents and young adults, specifically 8th-12th graders. WHY ARE SO MANY CHILDREN SMOKING!!!

In my experience, any time I have asked someone why they smoke marijuana, they claim that it helps relieve stress. Even in popular music, artists sing/rap lyrics about getting high to relax. I’m sure you all are familiar with Drake, one of the most popular music icons of the decade (I loveeee Drake, so I’m bias. But he really is extremely popular). In his song “Fear”, which has over 6 million plays on youtube, he says, “I been getting high just to balance out the lows.” I personally have seen this one line quoted several times on twitter by tons of people. Also, New Frontier Data’s 2017 Cannabis Perceptions Survey reports that of users, 55% say they use it for relaxation purposes, and 40% say they use it to relieve stress.

This made me wonder, how true is this? And if it is really true, what part does our brain play in making marijuana relaxing?

It was already well known that there are areas in the brain called receptors that are specifically for cannabis (another common name for marijuana) to bind to and create an effect in the body. However, a study by Ramikie et al. (2014) found for the first time that there are cannabis receptors in the Central Amygdala. This was a HUGE deal because the amygdala is the structure in the brain that is involved in regulating anxiety and the stress response. Having cannabis receptors in that specific region could help explain why marijuana users say they take the drug mainly to relieve stress and anxiety.

These receptors in the brain weren’t created intentionally to bind marijuana, though. Our body has its own natural form of cannabis, called endo-cannabinoids, that it releases to bind to these receptors. The receptors are located in various regions of the brain, so when the endo-cannabinoids bind there can be a multitude of effects on pleasure, memory, thinking, concentration, movement, coordination, and sensory and time perception. THC is the major chemical in marijuana, and according to the National Institute of Drug Abuse, it has a very similar chemical structure to one of the body’s natural endo-cannabinoids, anandamide. This similarity in structure allows the THC to trick the cannabis receptors into thinking it is an endo-cannabinoid. The THC binds to the receptors in place of the endo-cannabinoids,  and thus, marijuana can also have similar effects on the body.

Anandamide vs THC

This image shows how THC can bind to the cannabis receptors in place of the endo-cannabinoids, thus regulating many body functions.

Similar to humans, mice also have these cannabis receptors and natural endo-cannabinoids in their brains. Ramikie et al. (2014) wanted to understand the role of endo-cannabinoids, and their effect on the central amygdala. To do this experiment, they used a mouse model and fluorescently labelled the cannabis receptors so that they could be easily visualized using special microscopy techniques. They specifically observed the amygdala, and found that there actually were a significant number of cannabis receptors present in this area. They also found that the amygdala creates and releases its own natural endo-cannibinoids.

So what exactly does all of this mean? By finding cannabis receptors in the amygdala, and knowing that THC can bind to these receptors, researchers have potentially identified exactly how marijuana regulates stress and anxiety. However, there are down sides to this. When a person smokes marijuana, THC overwhelms the cannabis receptors by quickly attaching to them in place of the endo-cannabinoids. This interferes with the ability of the natural cannabinoids to do their job of regulating bodily functions, which can throw the entire system off balance (Scholastic 2011). So yes, while marijuana’s THC can reduce anxiety, chronic use of the drug down-regulates the receptors, which will actually increase anxiety. Down regulation occurs because over-activation of the receptors causes them to become less sensitive to the cannabis or endo-cannabinoids binding to them, which causes the receptors to need more cannabis in order to regulate natural bodily functions. This can lead to a habitual cycle of increasing marijuana use that, in some cases, leads to addiction.

What is great about this article is that the researchers used a relatively common imaging technique to understand a popular phenomenon. By finding the cannabis receptors within the amygdala, this study introduced ground breaking research that demonstrated how exactly marijuana can potentially regulate stress and anxiety, when used in moderation.  However, this study was limited because it only set out to locate the receptors and see their activity. There should have been a behavioral aspect to the study to determine how activation of the cannabinoid receptors changes behavior. The amygdala has a multitude of functions, and by including a behavioral aspect to the study, we would have been able to see exactly which functions the endo-cannabinoids play a part in.  Going forward, it would be interesting to test the effects of THC on these receptors in mice, and actually observe the effects of different amounts during a stressful situation.

So to answer my earlier question– yes, I guess it is true that marijuana really does relieve stress (when used in moderation). Neuroscience really does have the answer for everything!

Thanks for reading!




Ramikie T, Nyilas R, Bluett R, Gamble-George J, Hartley N, Mackie K, Watana M, Katona I, Patel S (2014) Multiple Mechanistically Distinct Modes of Endocannabinoid Mobilization at Central Amygdala Glutamatergic Synapses. Neuron 81(5): 1111-1125.

“The Science of the Endocannabinoid System: How THC Affects the Brain and the Body” (2011) Scholastic.

Map from Google Maps.

Children Smoking:

National Institute on Drug Abuse:

Drake youtube reference:

New Frontier Data’s 2017 Cannabis Perceptions Survey:

THC & anandamide:

THC & Cannabis receptor:

When You Smile to the World, the World Smiles Back

I have been in Paris for two weeks now, and I am still marveling at the sights and beauty of this new world around me. For anyone who doesn’t know, this is actually my first time out of America, so I have never really experienced culture shock like I have here in Paris. There are so many differences I have noticed, from restaurants only giving room temperature tap water to drink for free, to having to pay for bags in the grocery store, to the language barrier I deal with everyday.

If you know me, you know I am ALWAYS smiling. No matter what I’m doing, or who I’m talking to, 99% of the time I have a huge smile on my face. When I first got to France, we were staying at the Ibis Hotel near the Accent Study Abroad center in the heart of Paris.

As my friends and I were roaming the area, I kept making awkward eye contact with the French people walking, and I noticed something super strange: NONE OF THEM SMILED. It’s regular for me to make eye contact with someone, and even if I do not know them, I smile because where I’m from, that is the polite thing to do. However, I smiled at each and every one of these people, and each of them stared back at me with a blank expression. I honestly thought it was so rude. I immediately turned to my friends and said, “Did you guys notice that nobody here smiles? Isn’t that like human nature to smile at people? French people are so rude.” Even my friends thought that smiling at strangers was just the way the world worked, and even they were confused by this lack of expression from the Parisians. Once I got home, I googled “Why don’t French people smile?” (also if you know me, you know I google absolutely everything). I found a very interesting blog post about how that is just a major cultural difference between Americans and the French. Apparently, French people reserve their smiles for people they actually know. In fact, that actually find it strange when strangers smile at them, and they think it means they are making fun of them (Paridis 2013).

A photo I took walking down the street. Normally, it is pretty normal for people to not smile when they are just walking, but I made eye contact with two people after this photo and smiled, and neither of them smiled back.

After reading this blog, I began wondering how these cultural differences came about. I started questioning if it was actually weird that Americans just smile at people we don’t even know, or are we just extremely friendly people? As a personal preference, I love smiling. I don’t understand why anyone would not want to smile at people whether they know them or not. Smiling is a universal sign of kindness, so why not share it with the world?

As I was searching this subject (on google of course), I came across a neuroscience research article that proved that smiling can affect the way our brains process other peoples’ emotions (Sel et al., 2015). The study, interestingly enough, was conducted in France in 2015. There were 25 right-handed men and women with normal vision who participated in this study. For the experiment, each participant was shown a set of 90 pictures depicting happy and neutral emotions. In two separate blocks, they asked participants to adopt either a happy or a neutral facial expression during a judgment task of the emotional intensity of the images presented. Previous research shows that intentionally putting on an emotional facial expression is directly correlated with increased activity in the emotional brain network (Kuhn et al., 2011). The participants were also receiving an EEG (a test to detect electrical activity in your brain) while they were performing the judgment task. An N170 is a component of the EEG that shows the neural processing of faces. Literature suggests that the N170/vertex positive potential (VPP) complex is the brain activity shown when people are observing others’ facial features.

Fig. 1 (A) Experimental manipulations: self-neutral block, participants were asked to maintain a neutral expression and relax their face; self-happy block, participants were instructed to hold a happy expression by biting on a pen horizontally with the teeth. Control manipulation: self-control block, participants were asked to purse their lips in order to hold a pen with their lips only. (B) Timeline of the stimuli presentation. (Sel, 2015)

By performing the experiment this way, researchers were able to determine the effect of the participants emotional expression on the brain mechanisms underlying visual processing for the observed facial expressions. If the face processing was independent of the participants emotional expression, then the VEPs (visual evoked potential; brain activity caused by a visual signal which is seen on the EEG) of observing other’s happy and neutral faces wouldn’t be affected by their own facial expressions.

However, as the researchers hypothesized, the results showed that the participants’ facial expression of happiness significantly altered the N170/VPP of when they observed other neutral faces compared to when they observed the neutral face while also having their own neutral expression (evidenced in the difference between the red and green lines in figure 2A below). The results suggest that when people are smiling, they actually observe other neutral faces similarly to the way they view a happy face.

Fig. 2 (A) Grand average VEPs when observing happy faces (green: self-happy condition; red: self-neutral condition) and neutral faces (blue: self-happy condition; black: self-neutral condition). (B) Selected electrodes included in the ANOVA (Sel, 2015)

The results support the hypothesis that intentionally adopting a certain facial expression can change the subjective feelings corresponding to that emotion, which then influences perception of other’s facial expressions. They show for the first time that a person’s happy expression acts as an influence on visual processing, modulating neural activity when one observes neutral faces as compared with happy faces.

One strength of this study is that after the study, they went back and added another control to further validate their conclusions. Based on the way the study was conducted, it can be argued that the effects of self-happy expression on visual processing of others’ facial emotions could just be based on the contraction of facial muscles in general, rather than specifically smiling. To rule out this possibility, the researchers added a control in which the participants had to clench their mouths in a way that prevents smiling, but still contracts facial muscles. The results of the control were the same as they were for the self-neutral expression, which further proves that the effects shown in the VEPs to neutral faces are specific to the participants smile. This reassures that there is a direct contribution of one’s own facial expression of happiness to the way that person visually processes others’ faces.

A weakness I found in this study is that when choosing participants, it is not stated if they ruled out people with certain mood disorders, such as bipolar disorder or manic depression, that could automatically influence how they perceived the others’ emotional expressions. I think that going forward, it would be interesting to specifically test how the effect of smiling can work in people with mood disorders.

As for me, I am completely happy with the results of the experiment. It just goes to show that really, if you smile at the world, the world will smile back at you (at least you will perceive it that way).

Until next time,

Keep on smiling!



Kuhn S, Muller BC, Van Der Leij A, Dijksterhuis A, Brass M, Van Baaren RB (2011) Neural correlates of emotional synchrony. Social Cognitive and Affective Neuroscience 6: 368–74.

Paradis V (2013). Don’t Smile!. French Truly. Web.

Sel A, Calvo-Merino B, Tuettenberg S, Forster B (2015) When you smile, the world smiles at you: ERP evidence for self-expression effects on face processing. Social Cognitive and Affective Neuroscience 10.10: 1316-322.