In his 1996 autobiography Dreams from My Father, presidential candidate Barack Obama admitted using alcohol and drugs in high school. Obama was unusually frank compared with Bill Clinton and George W. Bush—to name just two politicians reputed to have used drugs.

Obama raised the issue again in November in Manchester, N.H. In response to a request by Central High School's principal that he reveal his "human side," Obama discussed his high school years in Hawaii: "I was kind of a goof-off. . . . There were times when I got into drinking and experimented with drugs." He added that he had righted himself to become a "grind" by the end of college.

The issue reared its head again recently when an influential New Hampshire Democrat and Hillary Clinton supporter, Bill Shaheen, said Obama's drug use made him vulnerable to attacks from Republicans. Shaheen quickly retracted his remarks, then resigned, but voters' attention was directed to Obama's teen behavior just weeks before the Jan. 8 New Hampshire primary.

Bush and Clinton are likely only the tip of the iceberg of prominent people who have sampled illicit substances. According to the University of Michigan's Monitoring the Future Survey, in 2007 about half of high school seniors had used an illegal drug. As the baseball steroid scandal indicates, drug use is widespread in America.

Of course, alcohol is always with us. In 2007, more than seven of 10 seniors had consumed alcohol, and well over half (55 percent) had been drunk. These figures rise and fall over the years: in 1980, the spring of Obama's eighteenth year, two-thirds of seniors had used an illicit drug and more than 70 percent had consumed alcohol in the previous month.

Presumably few of the more than 110 million Americans who, according to the National Survey on Drug Use and Health, have used illicit drugs volunteer this information. Since the overwhelming majority of them have grown up to be productive citizens, there's no need to know about their youthful misconduct. This is the logic of Republican presidential candidate Mitt Romney: "It's just not a good idea for people running for president of the United States, who potentially could be the role model for a lot of people, to talk about their personal failings while they were kids, because it opens the doorway to other kids thinking, 'Well, I can do that too.'"

Subtracting the approximately 20 million current drug users from the 110-plus million who have ever used, we see that almost 100 million Americans have left drugs behind. Neural research indicates that adolescent brains program kids to try risky behaviors. Can it be good for them to learn that as they mature they can, and will, straighten out and fly right?

This is the opposite of the approach of nearly all school drug education programs. Here the logic is to troop in people who have ruined their lives by their drug use and drinking. But there are reasons to believe that kids reject negative messages from figures like these, and that scare tactics alone don't work. Research on effective drug resistance programs finds that the best ways to prevent substance abuse are for kids to develop skills, feel good about themselves, have positive peers and look forward to their futures.

From this perspective, Obama's message that he briefly stumbled but then righted himself to achieve success may be just what the doctor ordered!