One of the teachings of Buddha was called The Middle Way. It’s simple: strive for equality between polarities. For example, on the parenting continuum, authoritarianism harshly scolds children, makes them obey out of fear. On the other end, hands-off parenting leads to more drug use, and less academic achievement. Authoritative parents take the best of both, leaving out the cruelty and disinterest.

Where am I going with this? Views of marijuana used to be very  negative. Now, they are quite positive. Ironically enough, weed was much, much more safe when it was most stigmatized.

These days, marijuana is far from a relatively harmless cup of coffee. That’s mostly speaking for THC, and cannabinoids that act similarly.

For starters…

So let’s address the elephant in the room. Is smoking a bit of bud every now and then harmful for people who have issues with emotional wellness (my term for “mental health”)? The short answer: yes, it likely worsens symptoms. However, I am bias against marijuana. That’s why hard evidence – well-conducted studies themselves – are posted in support of my position. That said, not all of the effects are negative. In the right situation, for the right person in the right dosage, marijuana can be invaluable.

I’m switching gear now. The following study is amazing. Why? Because a systematic review is one study made out of many other smaller studies. It makes a conclusion based on a general trend. But here we have a well-conducted systematic review study of 68 other systematic reviews on health and harm of marijuana. The image generated considers tens of possible harms.

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“Summary of evidence. Each dot represents a systematic review. Each third represents the conclusion about harm: the bottom third is no evidence of harm, the middle third is inconsistent evidence and the top third is evidence of harm. Reviews are organized within each third based on quality such that higher quality are near the top of the respective third and lower quality reviews are near the bottom. Some reviews reported on multiple outcomes and are represented accordingly.”


Again, these are straight studies, not opinions. Some are of greater quality than others. But still, we have about 14 possible, significant medical issues that arise for long-term users; when used in adolescence; and about 12 medical problems from acute use, which overlap.

As in the other pages, a summary of conclusions will precede more detail and source links.

  1. Long-term
    1. Directly physical
      1. Neurotoxic (to the hippocampus) (3)
      2. Neurotoxic (reduces gray matter) (3)
      3. Toxic to fetus in pregnancy (2)
      4. Impaired neurocognition (2)
      5. Respiratory issues (2)
      6. Heart issues (2)
      7. Neurotoxic to white matter
      8. Neurotoxic (to the amygdala)
      9. Neurotoxic (to prefrontal cortex)
      10. Increased incidence of brain and lung cancer
      11. Reduced health outcomes on many different levels
    2. Directly mental
      1. Increased incidence of mood and psychotic disorders
      2. Dependence
  2. Use in Adolescence
    1. Directly physical
      1. Neurotoxic (to the hippocampus) (2)
      2. Neurotoxic (to white matter of corpus collosum)
    2. Directly mental
      1. Much greater risk of a psychotic disorder (3)
      2. May act as a gateway drug to more harmful substances (2)
      3. Significantly decreases academic achievement (2)
      4. More severe side effects (2)
      5. Greatly increases incidence of cognitive issues
  3. Acute Effects
    1. Directly physical
      1.  Increased incidence of car accidents (2)
      2. Increases activation of frontal and anterior cingulate cortex
      3. Ingesting toxins when smoked
      4. Lack of evidence for epilepsy
      5. Lack of evidence for glaucoma without significant side effects
    2. Directly mental
      1. Significantly impairs cognition (3)
      2. Increased incidence of suffering a psychotic episode in healthy people (2)


But that’s not at all to say that marijuana is a useless plant. It can fulfill many different functions.

* Also applies to use when young, during substantial growth of the brain

Sources:,,, Uppers, Downers, All Arounders: Physical and Mental Effects of Psychoactive Drugs,,, Ben Komor, Dr. Laura Wray-Lake