Drug control policies, like gun control policies, tend to be driven by irrational fears rather than a calm assessment of the facts. When Congress banned marijuana back in 1937, the few legislators who had heard of the plant knew it as the "killer weed" supposedly responsible for horrifying homicides. Several years before Congress banned LSD in 1968, Timothy Leary and Richard Alpert observed that "psychedelic drugs cause panic and temporary insanity in people who have not taken them." The Drug Enforcement Administration imposed an "emergency" ban on MDMA back in 1985, after it became clear that people were having fun with it at parties and dance clubs, and only now is it beginning to emerge again as a legitimate psychotherapeutic catalyst. When states began banning Salvia divinorum in 2005, legislators were trying to protect the youth of America from a psychedelic herb that was not nearly as dangerous as they supposed and in any case never became very popular.

This year various drug scares influenced public opinion and public policy. These five stand out.

5. Ice, Ice Baby

A study of children who were prenatally exposed to methamphetamine, published online by the journal Pediatrics in March, prompted alarming headlines that recalled the "crack baby" panic of the 1980s and '90s. "'Meth Babies' Show More Behavior Problems," Reuters announced. "Mom's Meth Use During Pregnancy Causes Kids' Behavioral Problems," reported CBS News.

But just as the warnings about crack babies handicapped for life by their mothers’ drug use turned out to be wildly overblown, there was less to this study than the press coverage suggested. The researchers, led by Brown University psychologist Linda LaGasse, claimed to have identified “an important public health problem” that could “place tremendous burdens on society” based on small differences in test scores that may not even have been caused by meth exposure. As with the "crack baby" research, the major weakness was failing to account for all of the relevant differences between women who use a notorious drug when they're pregnant and women who don't.

Next: Got those caffeine jitters.

4. Energy Drink Crisis

Two years ago sensational reporting about the allegedly unique hazards posed by alcoholic energy drinks led to a federal crackdown that forced the reformulation of malt beverages like Four Loko, which no longer contain caffeine. That change did not satisfy crusading journalists such as New York Times business reporter Barry Meier, because it turns out that ordinary energy drinks still contain caffeine—enough to kill you, maybe. If you consume all 18 servings in a bottle of MiO energy drink concentrate, Meier reported on October 23, you will get 1,060 milligrams of caffeine—"more than enough, health specialists say, to sicken children and some adults, and even send some of them to the hospital." Meier also has suggested that two 24-ounce cans of Monster Energy drink, containing substantially less caffeine than two 16-ounce cups of Starbucks coffee, pose a deadly threat to consumers.

Next: Whatever happened to the real stuff? 

3. Fake Pot, Real Law

This year Congress banned "cannabimimetic agents" used to make synthetic marijuana, a.k.a. K2 or Spice. It was not clear which harm tied to fake pot was decisive: Was it goat shooting or dog eating? But it was clear that the new law aimed to remedy a problem created by an old one. Although the fear that little-researched compounds meant to simulate the effects of THC might pose unknown risks was not fanciful, the logical alternative—legalizing the much better known plant for which these products substitute—was never considered. Except by 21 members of Congress and millions of voters in Colorado and Washington.

Next: Is high school more high than it used to be?

2. The Kids Today: Always More Stoned Than Ever

Survey data indicate that almost half of Americans have tried pot by the time they graduate high school. But more powerful than the average teenager's urge to smoke pot is the average drug warrior's urge to warn that more teenagers are smoking pot than ever before. Last May the Partnership at Drugfree.org (formerly the Partnership for a Drug-Free America) announced that "heavy marijuana use" by teenagers was "up 80 percent since 2008." That press release generated stories with headlines like "Study: Teen Marijuana Use on the Rise," "Pot Use Soars Among Teens,Survey Finds," and "Survey: Teen Marijuana Use Surging"—even though the study cited by those articles, the Partnership Attitude Tracking Survey, actually showed that marijuana use by teenagers remained essentially unchanged between 2010 and 2011.

Drug czar Gil Kerlikowske argues that medical marijuana laws and efforts to legalize recreational use encourage teenagers to smoke pot by sending "the wrong message." That theory has never fit the facts very well, whether you look at cannabis consumption trends in relation to the enactment of medical marijuana laws or compare states with such laws to states without them. Now the latest Monitoring the Future Study indicates that marijuana use has declined among eighth-graders and 10th-graders while remaining steady among 12th-graders even as pot tolerance has hit record highs. Conversely, pot smoking by high school students remains substantially below the levels recorded in the late 1970s, when the idea of legalizing marijuana was much less popular.

Next: So powerful you don't even have to take it.

1. Face-Saving Drug Ban

For a month last summer, major news outlets accepted and propagated the idea that synthetic stimulants sold as "bath salts" were responsible for a grisly attack in which one man chewed off most of another's face on Miami's MacArthur Causeway. The story gave us classic headlines like "Bath Salts, Drug Alleged 'Face-Chewer' Rudy Eugene May Have Been On, Plague Police and Doctors" (CBS News) and "New 'Bath Salts' Zombie-Drug Makes Americans Eat Each Other" (Russia Today).

Rep. Charlie Dent (R-Pa.) jumped on the story like Rudy Eugene (above left) did on poor old Ronald Poppo. "When they learn about this face-chewing situation in Florida," Dent  told Roll Call in early June, "hopefully that will change a few minds." Dent was referring to the debate over his proposed ban on stimulants used in "bath salts." Apparently he got his wish, because a few weeks later Congress approved the Synthetic Drug Abuse Prevention Act of 2012, which bans two of those substances, MDPV and mephedrone. On the very same day, toxicological tests revealed that Eugene, a.k.a. the Causeway Cannibal and the Miami Zombie, had not consumed "bath salts" after all.