"I'm happy we're ending our reliance on the criminal justice system to prevent use by minors. That's because it simply doesn't work [...] The best way to prevent underage use is telling kids what the real dangers are."
“You left off these statements from the doctor. I wonder why?
“I’m happy we’re ending our reliance on the criminal justice system to prevent use by minors. That’s because it simply doesn’t work [...] The best way to prevent underage use is telling kids what the real dangers are.””
Those are his personal (political, not medical) opinions.
The statements that I included were the factual statements he made about known medical issues with marijuana (known to be detrimental to brain development in children and teenagers). That is where his expertise is most pertinent.
There are well known detrimental effects of marijuana on adults as well.
Of course, there are well known detrimental effects from many legal substances - alcohol, cigarettes, sugar, etc..
It is good to be aware of them.
Moderate, occasional use of marijuana is safe for the great bulk of people, and effective for some common issues, like anxiety or poor appetite.
Heavy, chronic use however, is known to persistently alter neurotransmitter levels (Dopamine) and brain structure of adults, as well as to impair memory and motivation.
For some adults with borderline psychosis, marijuana (and THC extracts) are potent enough dopamine agonists to shift them over the line. Most anti-psychotic drugs work by limiting dopamine (which marijuana/THC increase).
In fact, anyone will hallucinate (the hallmark of psychosis), if given a large enough dose of THC. Some are simply more sensitive to it.