"IF WE CAN'T shut off the supply," said Newsweek magazine back in 1986, "maybe we can shrink the demand —by somehow persuading drug users to turn off, or never to turn on in the first place." In the spirit of that suggestion former first lady Nancy Reagan urged young people to "just say no" to drugs. This simple, straightforward message, now familiar to every student in America, can't do the job alone. According to Robert Schwebel, a clinical psychologist in Arizona and vice chairman of the School Chemical Abuse Prevention Committee, "Saying no is not enough. Children need to be empowered. Young children need an opportunity to learn positive attitudes and basic life skills. Teenagers need dialogue and discussion with their parents. 'Just Say No' is not very helpful advice considering that rebelliousness is a major correlate of drug use by teenagers." For drug...