More on evidence of psychosis and marijuana

BBC NEWS | Health | Cannabis 'disrupts brain centre'

This report indicates that some very specific experiments with THC should really be putting the final nail in the coffin of the the arguments against there being cause and effect between marijuana use and schizophrenia.

Also, it notes that:

Experts are concerned that street cannabis is becoming increasingly potent. It is thought that average THC content has risen from 6% to 12% in recent years.

This increase in potency is highly disputed by some, but I presume "the experts" do have some proper basis for the claim.

An increase in THC sounds to me like a more plausible explanation for the danger of hydroponically grown marijuana, rather than it being due to the pesticides and other chemicals used while it is growing.