Unfortunately it's hammered on so hard, and without nuance, that kids will discard it with the other half-truths that are told. And also the tendency for families to cover up and hide any "shameful" facts like uncle Jim having spent some time in a facility, that kids might not know at all that there's a family history.
DARE is one of the reasons I started smoking cigarettes. The only time the teacher was ever actually honest was when he described the effects of nicotine. Everything else was half-truths and scary lies.