The Link Between Marijuana And Dopamine

Although cannabis might not be physiologically addictive, the effects it has can still be linked to some form of dependence. Seen as it's not chemically addictive, cannabis won't have as harsh of withdrawal symptoms as alcohol, tobacco or any illegal drugs. But what it may impose on the consumers, is a form of psychological dependence. This results from long-term consumption. Users will get used to smoking weed and it becomes hard to stop once you roll up daily. This is because of the relationship cannabis has with a chemical in our brain called dopamine.

WHAT IS DOPAMINE?

This is a neurotransmitter that takes part in our brain's reward system. It will respond to pleasurable stimuli. Dopamine is released during things that are good for us like eating, sex and sleep. Many drugs will target the increase of the dopamine level because it makes us feel happy for no reason at all. It also helps us regulate mood and emotional responses that will trigger anticipation before an action we enjoy. This is why you feel a slight achievement satisfaction when high. Your brain actually believes you just did something good for yourself (and in a way, you did).

On the other hand, the lack of dopamine can also be very, if not more dangerous. This is associated with people who enjoy taking risks, referred to as "adrenaline junkies". People get addicted to dopamine as they experience so little. This can also be dangerous for different reasons. You'll be more prone to involving yourself in dangerous activities. Another danger of a low dopamine level is that it can lead to Parkinson's disease. It happens because the disease will lead to a decrease the dopamine-producing neurons. So, whether the disease causes this or the disease is caused by the decrease, the result is unfortunately the same.

HOW DOES IT INTERACT WITH CANNABIS?

Like many drugs, marijuana in the short-term will increase the dopamine level in the brain. This happens in an indirect way. Cannabis does not purposely do this. What THC does, is bind to CB1 and CB2 receptors in the brain. Dopamine neurons do not contain any cannabinoid receptors, therefore cannabinoids cannot act directly on this. What is interesting, is that GABA neurons are used to limit the dopamine neurons in the reward pathways. But these GABA neurons do contain cannabinoid receptors which in turn inhibit them. And just like in mathematics, two negatives will equal a plus. By inhibiting what inhibits dopamine neurons, cannabinoids indirectly increase the dopamine level in the brain.

This function is already carried out by our endogenous cannabinoids. And this is, why a lack of these chemical compounds can also be dangerous. It can lead to symptoms of depression and anxiety. In a 2013 paper^[1], mice born without cannabinoid receptors ran around 30% less in the running wheel than those who had normal brain function (yes, time spent in the running wheel is supposed to measure happiness in mice. Don't ask me.). The researchers concluded that the endocannabinoid system is responsible for the everyday release of dopamine during activities.

SHORT AND LONG-TERM EFFECTS ON THE BRAIN

It appears that we can't refer to the relationship between cannabis and dopamine. THC has a different effect on dopamine than CBD. What you read above was all about THC. Because CBD does not actually interact with CB1 or CB2 receptors, it's impossible that it would cause the same effects. A study^[2] looked into this in 1997 and came to the same conclusion.

A 2016 paper^[3] also stated: "Acute THC administration causes increased dopamine release and neuron activity, whereas long-term use is associated with blunting of the dopamine system." This is fairly easy to understand. Before our body gets used to it, we experience an increase in dopamine. When the system realises it's always going to be fed external cannabinoids, it slows down the production of its own. This is the case with most substances and their effects on the body.

What is interesting regarding cannabis and when comparing it to other substances, is what happens after stopping consumption. The Department of Psychiatry from the New York State Psychiatric Institute compared^[4] the brain of past marijuana consumers with that of a non-consumer control group and the results were surprising. After a certain period of time, the dopamine receptors in the brain's reward system had returned to the norm. These could not be differentiated from the control group.

ONLY THE FUTURE WILL TELL

Unfortunately, there isn't enough information out there for any decisive conclusions, but research is coming. A lot of information is still based on clinical animal studies, which have a lot of limitations when it comes to real-world applications. Humans are also thought^[5] to have a genetic component that influences this relationship between the marijuana plant and dopamine.

Hopefully, with the legalization happening at a global scale, we'll start seeing more research going into this relationship. And especially the relationship with the different cannabinoids.