This is anecdotal, but having known schizophrenics, make sure your son stays away from drugs (e.g. marajuana and the like). I had a close friend who attributed his very bad schizophrenic symptoms to an increase in drug use (specifically marajuana). Correlation does not imply causation, but in this case, it's probably not worth the risk.
By "serve as catalysts" do you mean "make more severe," "make more frequent," "make appear earlier in life," or perhaps all of the above, or perhaps something different?
> Several studies have suggested that regular, long-term cannabis use is one of a number of environmental factors that, in combination with certain genetic predisposing factors, may significantly increase a young individual’s chance of experiencing psychosis and developing schizophrenia. However, numbers of people being diagnosed with schizophrenia remained stable over time during which the number of cannabis users increased and average strength rose significantly.
