sounds like propaganda, theres plenty of other shit we ingest on a daily basis that they put in our food and water and breathe from the air that could change your brain chemistry. even natural foods change the bodies chemistry depending on the ph of the food itself. I would think it would be more likely a genetic factor. I hear studies have shown that mj actually helps people with bipolar.
and for your brothers, sorry to hear that
maybe they were mentally scarred from thier college initiations???