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How Does Marijuana Affect Dopamine?

By on December 4, 2012

Summary (click to view)

  • Dopamine is a chemical used by the brain in transmitting signals
  • Dopamine is responsible for feelings of happiness and pleasure
  • All substances of abuse cause a release of dopamine, which is part of the addictive nature of drugs
  • THC also causes a release of dopamine in the brain
  • During withdrawal, dopamine levels will temporarily decline
  • Long-term use of cannabis does not impact overall dopamine levels 
  • Dopamine pathways of the human brain. Image source. – Despite all of the shortcomings and health hazards associated with using drugs, there’s no arguing the fact that drugs – including everyday substances like alcohol and caffeine – make their users feel good, at least in the short run.

    This reinforcing and dangerously addictive quality of drugs can be attributed to an essential chemical in our brain called dopamine.

    What is Dopamine?

    Dopamine belongs to a class of chemicals known as neurotransmitters, which are chemicals used by the brain in transmitting signals. But dopamine is not just any neurotransmitter…

    All substances of abuse share at least one thing in common – they cause a release of dopamine. Why is this important? Because dopamine is also known as the “feel good” neurotransmitter and is responsible for feelings of happiness and pleasure. As a result, dopamine plays a large role in the addictive quality of drugs.

    In addition to inducing pleasurable feelings, dopamine also influences the following functions:

  • Sleep
  • Mood
  • Attention
  • Working memory
  • Cognition
  • Voluntary movement
  • Motivation
    Low levels of dopamine have been linked to disorders such as ADHD and Parkinson’s Disease as well as problems with addiction (i.e. addictive personalities).

    How Does Marijuana Affect Dopamine?

    Early research seemed to suggest that cannabinoids – the active constituents of marijuana – did not increase dopamine levels like other drugs do.

    Although thought-provoking, the findings would later be dismissed as inaccurate and an overwhelming amount of evidence now confirms that THC – one of the cannabinoids found in marijuana – does in fact cause a temporary increase in dopamine levels.

    This rise in dopamine is mediated by CB1 receptors and occurs at a region of the brain known as the nucleus accumbens. Scientists believe that increases in dopamine at the nucleus accumbens are responsible for the reinforcing and rewarding properties of all known drugs of abuse.

    Dopamine and Cannabis Withdrawal

    Withdrawal occurs when a person stops taking a drug after a period of sustained drug intake. The result is a negative emotional state that enforces drug seeking and cravings.

    Studies have shown that during withdrawal from many common drugs, dopamine levels fall below their normal (i.e. baseline) levels – contributing to the negative emotional state of withdrawal. This decrease in dopamine has been observed during cannabis withdrawal as well.

    Dopamine and Long-term Cannabis Use

    Studies have linked the long-term abuse of substances such as alcohol, cocaine and heroin with a decrease in the brain’s overall production and release of dopamine. Cannabis users can breathe easy, however, as a study published in 2012 found that long-term cannabis consumption does not result in permanent changes in dopamine levels.

    • Lewis Parker

      “overwhelming evidence” directs you to a government-monitored website.
      You should be ashamed of yourself.

      • themclauchlins

        Pubmed is a library of medical studies using the medline database. Many well conducted studies with numerous authors are indexed in this library. If you are concerned about the bias in the individual studies, you must follow the money. Finding the source of the funding and critically appraising the article for the intent and the quality of the study will give you more information.

        For the particular article you have been so critical about, the grant funding looks to have come from the National Institute of Health and Health and Human Services, which would be government funding. However, the authors come from Department of Anatomy and Neurobiology, University of Maryland School of Medicine. I think this looks to be a legit study, done on mice, that shows there is an effect of cannabinoids on the dopamine level.

        You should be ashamed of yourself for jumping to conclusions!

    • chris9465

      Hahaha any website about any drug that brings you to a DOT GOV website is a lie…….nothing true here just more government BS and propaganda the author is a fraud

    • Jane Peters

      Man made drugs are the ones that are harming people.

    • Will

      Why are people claiming this article is full of lies? It’s a fact that smoking/consuming marijuana releases an abnormal amount of dopamine in the brain which is why you feel “high” when you smoke it. It’s not neccesarily a bad thing the same chemical is released by your brain when you eat chocolate. The other people are just jumping to conclusions because they probably don’t even know what dopamine is. The only thing I would assert is false is the claim that you can become addicted to marijuana.

      • Karol

        well I’d say that eating chocolate is a bad thing as well, but that’s another discussion…

    • Larry

      The comment in the final paragraph overstates the study’s findings:

      “Chronic cannabis abuse or dependence, of mild severity, is not associated with the same magnitude of [dopamine] alterations observed in other addictions.”

      The researchers could only draw conclusions about the effects of “mild” use. The study noted that some individuals were unable to stay off marijuana long enough to qualify as participants. As a result, it’s inconclusive what the harm may be on these heavy users.

      The study also caveated that there may be an impact from use during adolesence. That bit requires further study.

      This article’s assertion that “[c]annabis users can breath easy” is premature.

      • Lynn Boostedt

        I smoked pot for a long period of time. When I stopped I was irritable for a couple days. I didn’t smoke for years. Pot is not the same physical addiction as other drugs. Opioid dependence is more of a physical dependance. I don’t smoke pot and I haven’t for a long time. I don’t drink alcohol either. As soon as pot is legal you can bet I will treat my brain to some elevated dopamine. You don’t have to. That’s your choice. But know this you don’t have a right to choose for others. People don’t OD from pot. Cannabis is more of a want to then a want than a need to.