Should we teach children to say "no" to drugs, or say "know" to drugs?

I believe that teaching children that 'drugs are bad and you shouldn't do them' is a completely ineffective, if well-meaning strategy for preventing drug abuse.

'Just say no' might be effective for young kids, but it's not little one's we're worried about--it's teenagers.

Teenagers are smart, and they know propaganda when they see it (and see it better than anyone else). They will ask questions, and when they can't get straight answers they will find out for themselves, or ask another teenager who has.

If we teach our young adults to say "know", we are teaching them to be informed about drug use. Isn't that the best thing?

For many, knowledge alone will satisfy their curiosity, and for the ones that decide to experiment anyway it will at least give them a basis to use responsibly and reduce the likely hood of tragic misuse. After all, it is ultimately their decision whether or not to use.

So, should we inform teenagers about drugs and responsible use, or try to scare them out of it altogether?

"Just say No!", or "Just say Know"?