Do consider that, in many places in the U.S., anti-drug programs deliver the same ruinous message about all drugs, regardless of their actual dangerousness or potential to harm. When the children exposed to this rhetoric discover that drugs are not uniformly lethal - oftentimes through experimentation - this has the effect of undermining fundamentally the messaging they've heard (while also serving to discredit the person who warned them in the first place - often a police officer or other authority figure).