This is pseudo-science.
The underlying assumption of a chemical basis for mental health is completely unscientific.
If someone is suffering from horrible conditions, there's no reason to expect any drug (including weed) to help. And, when social conditions are unchanged, of course the symptoms will get worse.
The actual solution is fixing the conditions causing the problem.
This "solution" is like telling someone not to take aspirin for a broken arm because their arm is going to be re-broken every day and drugs won't stop that. The aspirin is not the actual problem, even if it's hard on your tummy.
This bullshit aint it. These clowns aren't helping. Just another prohibition cash grab.