Welcome Ksman,

I have read your other posts. Addiction to marijuana is possible (1 in 10 chronic/habitual users, much less in occasional users), but less common than some other substances.
I think that your son's psychosis is more likely a result of the potpourri (synthetic cannabis, a.k.a. spice) than the real marijuana, and that his talking about "needing" THC and CBD may be his way (or belief in a way) of self-medicating what the synthetic stuff does -- or has done -- to him.

If you are not familiar with these substances, I think your best chance of helping your son is to learn the scientific truth about them (not the hype/propaganda). There is a lot of information available on the web, but I would caution you to filter it carefully, as there is as much or more dis/mis-information as credible scientific information floating around out there.

Here are a few articles as starting points, though I would urge you to delve deeper.

Cannabis (drug)
Tetrahydrocannabinol (THC)
Cannabidiol (CBD)
Cannabis dependence

Synthetic cannabis
Spice side effects

Best Wishes,

Doc