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What Makes Marijuana a ‘Psychoactive’ Substance?

By on January 23, 2013

Summary (click to view)

Psychoactive substance – any substance that acts to alter a user’s brain function
• Cannabis contains chemicals called cannabinoids that act on the human brain
• The most common psychoactive substances include coffee, tobacco and alcohol
• Psychoactive substances are split into 3 categories: stimulants, depressants and hallucinogens
• Marijuana doesn’t fit into any of the 3 groups
• The psychoactive effects of marijuana last for only a few hours after intake – Marijuana is frequently referred to as a ‘psychoactive’ substance, but what does this really mean?

‘Psychoactive’ – A Definition

Coffee is the most widely consumed ‘psychoactive’ substance. Image source

The term ‘psychoactive’ refers to any substance that acts to alter its user’s brain function. Cannabis fits into this category of substances because cannabinoids – the active ingredients found in cannabis – cross the blood-brain barrier after being ingested and act on various parts of the human brain.

For those who’ve never set foot in a biology class, the concept of foreign particles acting on the brain to change the way you think may seem like a terrifying thought, at first. However, one only has to consider the incredible number of everyday substances that fall under the category of psychoactive substances to understand how common such a concept is.

Coffee, cigarettes, beer and sleeping pills all contain psychoactive substances – chemicals that travel through the blood stream to the brain in order to elicit their desired effects.

Marijuana: Stimulant, Depressant or Hallucinogen?

Indeed, the class of substances considered to be ‘psychoactive’ is incredibly large. Scientists have further divided psychoactive substances into 3 groups according to their effects:

Stimulants (examples: coffee, tobacco, amphetamine)
Depressants (examples: opioids, barbiturates, alcohol)
Hallucinogens (examples: psilocybin, LSD, nitrous oxide)

Marijuana is an interesting drug because it doesn’t really fit into any of the 3 categories. Although it does exhibit some mild hallucinogenic effects, it is also thought to be a mild stimulant with effects that mimic that of a depressant. As a result, marijuana tends to be left out of the traditional categories of psychoactive substances.

The Psychoactive Effects of Marijuana

Marijuana exhibits a wide range of psychoactive effects in its user, perhaps due to how widespread the endocannabinoid system is within the human body. The following are just some of the psychoactive effects of marijuana:

Altered perception
• Change in mood
• Relaxation
• Euphoria
• Altered sense of time and space
• Impaired memory (high doses)
• Paranoia/Anxiety (high doses)
• Auditory/visual illusions (high doses)
• Hallucinations (very high doses)

The various effects of marijuana are ultimately a result of how cannabinoids interact with different parts of the brain. Luckily, these interactions are only temporary and will last for no more than a few hours (depending on the method of ingestion).

  • Benjamin Smith; Doctor

    Impaired memory was in apes when they nearly suffocated them to death in a small room with marijuana smoke, had nothing to do with marijuana, you’d forget short term too if you were struggling for oxygen for nearly ten minutes. Other than that, the rest of what you said is simply nonsense.Millions of people take cannabis as medicine every day and should do so without prohibitionist interference like yours. Common sense must prevail revealing the benefits of Cannabis legalization.

    • Hi

      This article isn’t even criminalizing marijuana, it’s strictly informative. So please calm yourself.

    • mutosheep

      Your license needs to be revoked you crackpot

  • Einsteinwasamassmurderer

    There is no psychoactive or brain altering effect of marijuana, unlike LSD or shrooms where you go on a “trip” or alcohol where your brain functions LITERALLY change.

    • Hi

      Not by smoking it, but taking high doses of THC such as extremely potent edibles it can have hallucinogenic effects. That’s why you hear about people eating too many pot brownies and then calling an ambulance thinking they’re dying.

      • pharmerdavid

        Hi hi, you are correct – ONLY when an overdose is ingested does medicinal cannabis have the potential to cause hallucinations, but used correctly it is NOT a “hallucinogenic”drug. This article correctly explains the difference between “psychoactive” and “hallucinogenic”. Personally I’ve overdosed by ingesting too much cannabis a few times, and I never had any hallucinations – just felt horrible and muscles felt paralyzed, and thinking clearly was difficult, but no hallucinations. I’ve also taking LSD, psilocybin, and mescaline – those are “hallucinogenic”. Why does the government ban hallucinogenic drugs? Because they help open our pineal glands, and connect us to Source of Creation…

        • Dmember

          Hallucinogenic drugs ‘help open our pineal glands, and connect us to Source of Creation’? I pretty much doubt that. Why not just read your Bible and get to know your Creator the natural way….

        • mutosheep

          Your anecdote does not change reality. Have fun circle jerking in the matrix you jonestown creep

    • Jane L Stanley

      Yes it does have an affect on the brain Einsteinwasamassmurder because of it’s ability to open up different avenues of learning in the brain. Then their is the euphoric feeling that happens in the brain. It just isn’t brain altering like some of the pharmaceuticals does to our brain functions. This brain altering effect is what makes it great choice for PTSD patients.

      • Dmember

        The pharmaceuticals are not anywhere near brain-altering compared to marijuana. Marijuana is brain-altering every time you use it.

        • mutosheep

          I think we are wasting our time on “pot good, tobacco bad” robot zombie Nazi lemmings

      • mutosheep

        Pot disables learning; it does not enhance it. Freaking crackpot stoners. It is also HORRIBLE for PTSD as is any hallucinogen when not used in a closed therapy session under close supervision. Also, the vast majority of pot being prescribed is inhaled as smoke, which is not healthy. The loss of intelligence, short term memory, and heightened auditory selection are specifically dangerous to PTSD patients. Taking pot to cure PTSD is like taking amphetamines to cure insomnia.

        • dflmnt

          You need a big dose of education. Everything you claim has been scientifically proven false.

    • Dmember

      You’re nit-picking. Marijuana causes enough brain-altering to make it unsafe for use when driving. ‘Tripping out’ is rather extreme, yes, but the psycho-effects of marijuana can also be severe.

  • John Harson

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  • CamMan

    it definitely causes psychoactive effects like explained in the paragraph its anything that changes the brains normal function through a chemical change, it might not create a hallucinations like lsd or psilyciban but it tricks your brain into thinking your hungry, or things seem better or feel better then they seem. which is a PSYCHOACTIVE effect of cannabis. but cannabis is good for you lol. well for me it helps my anxiety eating etc.