Marijuana’s Affect on the Amygdala Explains it’s Effects on Anxiety, Brain Damage on PET Scans

marijuanaOh do I get tired of hearing all the pro-marijuana folks argue about it’s virtues (it’s natural, it helps my ….. this that or the other … it’s my medicine,…it’s better than alcohol which is legal, it helps my anxiety, it helps me sleep, etc.)

Problem is it is also the leading cause of anxiety, depersonalization, and that can happen the first time you try it, the 10th time of the 1000th time. There is no guarantee, just because you are ok with it now, that you will always be ok.  Often once brain damaged, it is a struggle to get your normal brain back.  Taking THC or marijuana is like playing roulette with your brain and mental health.  The very conditions you are “treating” with THC, like anxiety or insomnia, are the very conditions it creates.  Try stopping and if it’s difficult, that is all the more reason you should.

The first study (which you can read here… )  “Multiple Mechanistically Distinct Modes of Endocannabinoid Mobilization at Central Amygdala Glutametergic Synapses,” demonstrated the mechanism by which THC alters the stress response and emotional learning.  What studies are showing is that we all have an internal endocannabinoid system that regulates anxiety by dampening the excitatory signals that involve the neurotransmitter glutamate. Acute and chronic stress and emotional trauma can reduce the natural internal buffering of the endocannabinoids resulting in anxiety. Marijuana works to reduce stress short term by the external application of cannabinoids thus reducing (for a time) anxiety and the stress signal, but paradoxically, chronic use down-regulates the receptors which increases anxiety.  Like most addictions, the initial desired effects of the drug eventually disappear leaving you worse off than you were when you started.

In a second study (found here… ) PET scans of cannabis users showed a 20% reduction in CB1 receptor activity, showing the brain damage caused by the chronic use.  Thankfully this study showed the damage to be reversible when participants stopped using cannabis.

Results of the study show that receptor number was decreased about 20 percent in brains of cannabis smokers when compared to healthy control subjects with limited exposure to cannabis during their lifetime. These changes were found to have a correlation with the number of years subjects had smoked. Of the original 30 cannabis smokers, 14 of the subjects underwent a second PET scan after about a month of abstinence. There was a marked increase in receptor activity in those areas that had been decreased at the outset of the study, an indication that while chronic cannabis smoking causes down regulation of CB1 receptors, the damage is reversible with abstinence.

If you are pregnant, think long and hard about the damage you are causing your unborn child.  The third study (seen here… ) shows permanent neurobehavioral and cognitive impairments from the binding of THC to the fetal brain, with repeated exposures disrupting the endocannabinoid signaling and has the ability to rewire fetal brain circuits. If you are the dad or other adult around a pregnant woman, you have no idea the damage you are causing, and don’t expect the pregnant woman to do what you can’t do.  Sorry to sound “Big Daddy” here, but I’ve seen too much damage not to make a strong statement on this point.  You only get one chance in the womb to do everything you can to minimize harm and maximize the nutrition for your growing baby.

Even if marijuana (pot, THC) is legal, that does not mean it is safe.  This study, (found here… ) “Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users,” adds to many others showing that earlier onset of frequent pot use triggers earlier psychosis (schizophrenia, bipolar, psychotic episodes). The study looked at more than 400 adults who were admitted to the hospital for their first psychotic episode.  Those who started using cannabis at age 15 or younger or who preferentially smoked high potency cannabis more often had earlier onset of psychosis than those who started after age 15.  Male users of cannabis had their first psychotic episode at average age of 26 compared to age 30 for non-users.  For women cannabis users, the first episode was at 29 compared to 32 for non-users.

Just as alcohol and tobacco are associated with significant health problems for frequent users and abusers, cannabis is associated with significant psychiatric morbidity. As states and governments look at the question of legalization, the bigger question should be whether or not legalization increases or reduces the use and abuse of this health hazardous product.

In the study published in the periodical Schizophrenia in 2013, (which you can find here… ) brain abnormalities and memory problems were found in individuals in their early 20’s, two years after they had stopped smoking marijuana suggesting there is persistent damage to important regions of the brain. Memory-related structures of the brain appeared to shrink and be collapsed inward, possibly reflecting loss of neurons/ brain cells.

In our push as a society to legalize marijuana, will this result in more or less intoxicated drivers on the road?  We already have 25% of teens who smoke marijuana acknowledging driving under the influence of marijuana. You can learn more about that here…

We now have a new cannabinoid to worry about: K2/ Spice which resulted in 28,531 emergency room visits in 2011.  These synthetic cannabinoids are frequently associated with psychosis.

In the study published in the journal Neuron, (and found here… ) schizophrenia symptoms were found to be linked to a faulty “switch” connecting  two important regions of the brain, the insula and the lateral frontal cortex. Drug use, particularly cannabis and stimulants are 3- 4 times (300-400%) more likely to go on to develop psychosis or schizophrenia.






Dr. Paul



  • People seek drugs like cannabis because they are missing necessary chemicals in their brains which their bodies should be producing. Gut & Psychology Syndrome (GAPS) explains this. The people who have psychotic episodes/schizophrenia after smoking marijuana are GAPS patients. Correlation is not causation. It is likely these patients are self-medicating an imbalance that was already there before the marijuana.

  • Concerned about Marijuana? Why?

    True, when your body is still developing you don’t need to introduce things that will slow you down. But after responsibility kicks in, you need something to combat the caffeine, sugar, fat, and mulitple other toxins that you consume from the atmosphere alone (Gas, oil, methane, carbon monoxide all have death rates when consumed).

    Marijuana is not a toxin. It has 7,000 years of recorded medical history from Ghengis Khan to the Egyptians, from Ancient Greece and Ancient Chinese, to George Washington and Queen Victoria. It was even on the U.S. Pharmacopeia in 1850.

    It wasn’t until America started a crude “War on Drugs” which in reality was a “War on Race” did marijuana become something negative. Now all of the sudden because colored races are seen smoking this substance is it now illegal to do so. Big Industries like Tobacco, Pharmacueticals, and our privatized Prison system pay good money to continue the false propoganda, but its all a lie.

    These studies do not convine me that marijuana is at fault. These studies also have very little participants. How can you conclude anything, especially psychosis, after only studying 400 people? The medical studies that conclude in a benefit from using marijuana as medicine usually study over 10,000 people before coming to a conclusion, and take into effect that other drugs, alcohol, and toxins being used come into play when conducting a study.

    I’m looking for research that can prove marijuana is a negative substance for our society, and this does not convince me.

  • And your point? We’ve all heard the extensive lists of reactions to presciption drugs…some FAR more dangerous. Why is it that the stuff doctors get perks to sell are acceptable but this isn’t?

  • Aimee

    People who are pro-marijuana have no idea what they are talking about. I was a long term smoker (17 years) and it ruined my life. I was lazy, unmotivated, did not make money, developed health problems including psychosis and my life became a total mess. When I quit, I went through absolute hell. Marijuana causes your adrenal glands to over work, which causes adrenal damage and that is the major problem which you have to deal with when you stop smoking. It can take from 3 months to a year for your adrenal glands to normalize. Adrenal fatigue makes you feel anxious, tired, moody, irritable, you have chest pain, heart pulpitations and you suffer from sleeplessness. When you suffer when you stop using something, surely it is common sense that the substance is not good for you???!!!!
    Our bodies are perfectly made machines and it deals with anxiety better in it’s natural state. When we put all kinds of substances into it, it messes up our chemical balance completely and then we need substances even more.
    It really pisses me off when people are so airy fairy about it and say it comes from a plant which is natural…so does heroine.
    Wake up and think about this when you are not stoned!!!!!

  • VetReporter

    Find me the LD50 for cannabis- then we can re-visit your anti-marijuana, reefer madness paranoid statements that warn us that a terrible depressive change can happen…at ANY TIME. Oooh, sounds scary huh? Just like the “Just Say No” campaigns we shoved down children’s throats in the 80’s – it’s based on single study critical reviews, anecdotal ‘evidence’ and the opinions of medical professions who apparently hate a natural, effective and safe alternative to pharmaceuticals.

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