The Link Between Marijuana & Dopamine

Based on medical research
MarijuanaBreak Staff MarijuanaBreak Staff / Updated on June 19, 2019

Marijuana & Dopamine

If you are a marijuana consumer, you might find that the plant increases your level of dopamine in the short term. The result is a wonderful feeling of euphoria where you believe just about anything is possible. Things are more humorous (almost everything in fact) and you feel at ease with yourself and the world.

However, new research has revealed something disturbing: long-term, heavy marijuana usage could reduce your levels of dopamine. Low dopamine levels are associated with a variety of medical issues including depression, fatigue, and mood changes. This is big news as an estimated 78 million Americans have tried marijuana – 55 million in the last year and almost 23 million in the last month. More importantly, of the 9.5% of adults that admitted marijuana use in a 2014 National Survey on Drug Use and Health, about one-third reported marijuana addiction symptoms.

What is Dopamine?


Although dopamine has been studied for over 60 years and has been the subject of an estimated 110,000 research papers, it is still a source of disagreement amongst neuroscientists.

Dopamine is a neurotransmitter that acts as a chemical messenger and transmits signals between the brain’s neurons (or nerve cells).

There are different neurotransmitters in different parts of your brain, and there are two main areas of the brain that produce dopamine: the ventral tegmental area and the substantia nigra. The actual combined area of these brain parts is less than the size of a postage stamp, but they produce dopamine which relays the signals that ultimately travel through the brain.

Once the brain cells that make dopamine die off, the result is a raft of problems. For example, drug addiction and Parkinson’s disease have both been linked to a lack of dopamine. Thus, many Parkinson’s patients have to take a drug in order to increase their dopamine levels so they can move about normally.

How Are Marijuana & Dopamine Linked?

Marijuana strains and phobia

Dopamine is the chemical responsible for activating the pleasure centers in your brain. When you smoke marijuana in the short-term, have sex, or eat/drink something you love, the pleasure you feel is caused by heightened dopamine production. The reason why illicit drugs are so addictive is that they activate this pleasure pathway, and you become hooked on the sensation before you even know it.

Short-term marijuana use is known to increase dopamine in your brain indirectly. While the cannabinoids contained in weed don’t act on the dopamine neurons directly, they do act on the body’s endocannabinoid system (ECS), which temporarily suppresses GABA inhibitors. GABA neurons are neurons that inhibit dopamine production – when they’re suppressed, dopamine production increases.

Endocannabinoids (the cannabinoids that are produced naturally by the body) play a huge role in our daily functions. A 2013 study by Dubreucq et al., for instance, looked at mice that had been born with no cannabinoid receptors. The researchers found that these mice used their exercise wheels up to 30% less often than healthy mice.

Marijuana Is Awesome for Dopamine Production in the Short-Term

Additional studies show that THC is more effective than CBD in terms of positively impacting dopamine in the short-term. A 1997 study on rats by the author French discovered that THC – the psychoactive compound of cannabis – stimulated dopamine neurons in the midbrain. It took almost 20 years for a study to show the same effects on humans, but the recent 2016 study by Bassong et al. accomplished exactly that.

French also conducted a similar study using CBD instead of THC, and found that there was no evidence of cannabidiol increasing the dopamine in reward pathways. In simple terms, the effect of THC on dopamine explains why you feel so good during and after a smoke. Overall, the new research suggests that marijuana users might want to cut down on use or risk long-term dopamine damage.

Does Marijuana Cause a Long-Term Reduction in Dopamine?

While the strongest body of evidence has appeared only recently, there have been studies on the effects of long-term marijuana use on dopamine for decades. A 1998 study by Jentscha et al. discovered that regular weed usage over a long period reduced the level of dopamine in the brain’s prefrontal cortex. This area of the brain is associated with complicated tasks such as memory, planning, and decision-making.

It was a 2016 study led by Professor Oliver Howes, however, that dropped the dopamine bombshell. While other prior studies had found links between heavy long-term cannabis use and anxiety, depression, and schizophrenia, researchers were unable to pinpoint the causes of these associations. Howe and his team believed they found the answer when they reviewed a host of previous studies on how THC affects the brain.

The authors of the study concluded the review by suggesting:

“THC exposure produces complex, diverse, and potentially long-term effects on the dopamine system.”

Moreover, they went on to say:

“these include increased nerve firing and dopamine release in response to acute THC, as well as dopaminergic blunting associated with long-term use.”

According to the authors of the study, the findings explain why long-term weed users are at greater risk of suffering from mental health problems. Howes was also critical of animal studies, saying they are far too short to offer any real insight. The team was also concerned about the existing gaps in marijuana research, particularly in regard to a lack of studies on what happens to our dopamine system once we stop using marijuana.

Final Thoughts on Marijuana and Dopamine

While it is important not to panic when hearing about the latest research surrounding the link between marijuana and long-term dopamine reduction, it should provide weed smokers with plenty of food for thought. We always advocate smoking responsibly, and this review of a long list of studies should only serve to strengthen our warning.

The bottom line is, it will take years of research on human patients before these findings can be either confirmed or questioned. What we do know, is that studies on animals are all but useless since they take place over a period of weeks and not years. For now, we will wait with bated breath to find out what else the scientific community has to say about marijuana’s link to dopamine.

Article Sources:

  1. Alen
    MJ can be enjoyed responsibly

    I smoked heavy THC for over a year several times a week and developed extreme anxiety after quitting cold turkey. It took me several months of diligent healthy lifestyle, eating heathy and exercising to get back to baseline. While I think MJ isnt as harmful as say alcohol or other hard drugs I do think it shouldn’t be abused and can be enjoyed responsibly.

  2. Angela Ortiz
    Science Students here?

    I think marijuana is great for stoners, and this article is meant for science students. Dopamine or something else, but marijuana definitely gives a great high if dabbed or smoked. Why go into the nitty-gritties of its composition?

  3. Joseph
    23 YO on college

    Been smoking for 3 years daily, sometimes only at night and sometimes during the day, i dont think i have depression but I sure have less dopamine, now that i moved to illinois theres no way i can smoke pot here. I needa mention that i have no issues to sleep, or to study. The only fact i approve about this is that I feel less motivate. But once I go to the gym or I date my gf I feel fine. All my stoner friends I asked em’ if they feel like me, all of em said yes. But they dont care.

    I’ll keep smoking pot but not daily just casually, or when I go to the beach

  4. Noa
    Be Warned!

    I’ve been smoking THC daily for six years and stopped using it 70 days ago. I noticed that I’m having difficulties with decision making and feeling my emotions. I also do not notice any improvements in my mood since stopping the drug. Reading this article further causes me to believe that smoking weed has sever long term side effects on my dopamine system that we might never recover from. To all people considering using this drug as a “natural remedy” I would advice extreem caution. Good luck

  5. TrapKick
    Cannabis and Dystonia

    I’ve been diagnosed with Dystonia which is a severe tightening of muscles. I have had 2 spinal fusion, nerve blocks, taken soooo many drugs and in the past 6 months I started cannabis. It has changed my life. My muscles are relaxed and o feel so much better. If you look at Dystonia it can be cause by a lack of dopamine. I’m working with a neurologist now, but cannabis has been a great troubleshooting tool for me.

  6. Branwen Brown

    and I have been on snri for 5 yrs now,, and they bring me more anxiety and many other issues, I use marijuana to calm these serious feelings,, I can’t face the crowd unless I smoke, I can’t manage the world these days, everything is overwhelming so I Stay away, go where I can keep calm, where the weed at,, Really clear that the meds are worse for me,
    Did any ever consider that perhaps the dopamine levels in people who have been depressed most of their lives are scarcly low, or was already halted in production,, so now when we add some natural cannabinoods we have relief and clarity, yes it makes ya feel like your are capable of pushing through the long list of challenges people face every day,, mostly lack of income to feed ourselfs properly,, with good food we’d all feel better,, but would you call food a drug because it brings pleasure,, no! the way you address this like its a Drug,, could simply be a supplement to the lack of joy one has the chance to obtain.. in this dog eat dog world.

    1. Meme
      Still not convinced. I will always use herb over pharmaceutical.

      Branwen brown.. Well said! With all the money in this world.. Isn’t it telling that NO scientist has concluded a full human test on cannabis. I wonder why that is!? Oh yes.. It brings far too many benefits and would crush Cancer research too. None of these studies advise the previous mental state of the persons being tested and is all too vague. I trust my gut that the good out ways the bad for my own needs.

      Also… “high Street cannabis” that has been mentioned for its high potency and possible added chemicals. Id just like to compare this to your average food and herbs you buy. If you don’t eat organic then its basically the same. Nutrients are added to cannabis for a fuller flower exactly the same as the nutrients and GMOS that are added into your daily foods. There is no difference! Apart from the fact you will NEVER know what your food is sprayed with (they wear protective gear to do this!) And if your close to your supplier, you may know exactly what is being put in your cannabis. Rest assured they wouldn’t need to wear protective gear and a mouth mask like your healthy fruit and veg at waitrose. Unfortunately this corporate greedy world makes it too expensive and difficult to access and diet on whole organic for many reasons £££££…..

  7. Ethan

    I used marijuana on a daily basis for three and a half years and then quit cold turkey. I’ve been struggling with sever anxiety and insomnia over the past 4 months, and have treated with an SSRI for a month now.

    While I am a fan of weed and will probably resume using recreationally one day, I advise against daily use of it.

    1. Ibby
      Weed is bad long term

      @ethan i was abusing weed for 19 years i stopped smoking it 5 months ago since stopping i have suffered severr mentel helth problems depression anxiety overthinking worrying loss of intrest in everything in life. Doctors put me on ssri a month ago was wondering how are you doing now if u could reply be much appreciated thankyou.

    2. David
      SSRIs are dangerous

      @Ethan, studies appear to show weed has fewer and less severe side effects and greater pharmacalogical benefit than SSRIs. A large Harvard studies showed that SSRIs are essentially placebo in benefit but toxic nonetheless.

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