Your brain on pot

Because pot has become legal in some states, researchers are scrambling to understand how it affects the brain. As such, the bottom line is that much research is still needed, however, one thing is abundantly clear:

Pot is messing with your brain. Here are two key ways that come up over and over in the research:

First, brain dopamine levels

DID YOU KNOW? New research has found that people who smoke marijuana over a long period of time produce less of a chemical (dopamine) that is linked to motivation, learning, reward and pleasurable emotions. Dopamine deficiency is present in a number of neurological conditions, including Parkinson’s Disease and attention deficit hyperactivity disorder. To be clear, in the short term, pot will spike dopamine and lead to positive feelings, but in the long term, the body won’t make the same amount of dopamine if it thinks it will get dopamine from another source. But these effects don’t last forever—if you quit using marijuana, the dopamine levels can go back to normal. 


THC (tetrahudrocoannabinol) is the primary psychoactive component of pot. There is substantial evidence that THC alters the brain’s reward system by decreasing the brain’s dopamine levels. 

Yes, pot lowers your dopamine levels. What is dopamine and why is it important to have regular levels? Dopamine is a neurotransmitter (chemical) in the brain that is linked to feelings such as happiness and pleasure. Therefore, lower dopamine levels change your mood, and not for the better. In fact, low dopamine levels are associated with neurological conditions like Parkinson’s Disease and ADHD. So basically, you do not want to voluntarily lower your dopamine level through marijuana use because you may put yourself at risk for long-term illnesses. Bottom line: Dopamine is an incredibly important factor in well-being and who you are, so much so that you do NOT want to mess with this chemical in your brain! Please refer to the Did You Know at the top of this section. 

Bottom line here: THC alters the delicate balance of brain chemicals.


DID YOU KNOW? Studies consistently show a link between pot use and psychosis. The more the drug is used, the higher the risk.


Second, your short-term memory

Smoking pot damages your short-term memory capacities.

When you use pot, the active ingredient THC can impair the normal functioning of different areas of your brain. In particular, THC can affect the part of your brain responsible for memory formation—the hippocampus. This is why so many people report not being able to recall events while under the influence of marijuana. The hippocampus is not functioning properly.


DID YOU KNOW? “The effects of THC resemble a temporary hippocampal lesion.” In other words, smoking a joint creates the effect of temporary brain damage.

(Source: Marijuana and Medicine published by the National Academies Press,

Moreover, the impact THC has on memory and the brain can also create an altered sense of time so that users do not have a solid understanding of how much time is passing. Yeah. Time warp in real life. Not good when driving or having to coordinate your body movements or even just having to get home on time.

So think about it….

You are still developing and growing (but you knew that already). Along with your body, your brain is also growing. It is wiring connections every second with everything that you do, think and say.

When you grow anything—for instance a plant—you try to give it optimal conditions for growth: nutritious food, water, great soil, plenty of sunlight, fresh air. You want it to thrive. Same thing with your brain. It’s a good idea to give it the best conditions to grow and thrive. Ingesting pot and sending it throughout your body and brain does not allow for optimal growth. It’s a little like placing your beloved plant in the direct line of the exhaust from a car everyday.

DID YOU KNOW? A decades-long study in New Zealand found that adolescents who used pot at least four times a week lost an average of 8 IQ points between the ages of 13 and 38.


For all people, drugs interfere with the brain’s ability to function well. But for teens, because the brain is developing, this effect is even larger with more long-term implications. For example:

  1. Since the prefrontal cortex is not fully formed yet, when you take drugs you are impairing something that is not fully functioning in the first place.
  2. You are generating (growing) brain connections that may begin to make drug use a habit. The pathway from habit to addiction is very short.
  3. You are growing brain cells in a smoke-filled construction zone. It’s unlikely that those brain cells and connections will ever be as good as they could have been without the smoke.

And then there’s tolerance….

Experimenting with pot, or any drug, will have an effect on your brain. One clear example of this is tolerance.

Tolerance is how much of a drug you need in order to feel the effects. Your tolerance goes up when you use a drug a lot—so you need (and sometimes crave) more of it to feel the same effects. This is actually a brain chemical change: a clear example of the reality that smoking pot changes how your brain works. 

BTW, tolerance is also one way pot becomes the “gateway” for more illicit (meaning dangerous, illegal) drug use. When the same amount of pot no longer creates a high, people often choose to move on to other drugs to feel that high, rather than to smoke more pot, more often. Please visit the Addiction Post to read more about tolerance and its cousin, sensitization. In the meantime, read the next post for a some data that backs up the little brain lecture we just gave you;).

Post Question:

Did you know before reading this post that pot use could effect your brain long-term? What concerns you the most about the effects on the brain?

Answer the post question here

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