Everything we need is supposed to be in the food we eat but due to processing foods to give them a longer shelf life and chemical fertilizers our food is essentially void of nutrients. For example fresh milk from cows starts to ferment within 2-3 days even when refrigerated. Most people are lactose intolerant because lactase is removed from the milk which is what breaks down the lactose. Also cooking food destroys many nutrients such as taurine in meat which was shown in cats that were deficient in it they would be mentally ill and generally unhealthy.
Gotta be careful with Cannabis. THC can accelerate schizophrenia in certain people that are predisposed. A lot of it is grown with chemical fertilizer and who knows what else gangs and cartels are using to get you addicted to it.