Read: What Atlantic readers thought about marijuana in the ’90s

Smoking lots of pot really can rob you of your ambition, and cannabis-use disorder—CUD, or pot addiction—is a real thing that can take away years of your productive life, if you belong to the roughly one-tenth of pot smokers who smoke too much and let cannabis get in the way of other things, like work, study, or family. Problem smokers keep smoking too much for 44 months, on average—“not a small chunk to take out a lifetime, especially a young lifetime,” Kleiman wrote. For that reason, Kleiman thought states should legalize pot in ways that would minimize excessive use. First, don’t let distributors advertise or otherwise encourage their customers’ habits. I once lived two blocks from a legal cannabis dispensary, and it took me a year to realize what it sold, so subtly did it market its product. Second, keep prices very high, far higher than the few pennies it would cost to grow and sell a joint. Make pot expensive enough that occasional users barely notice the cost but addicts do and feel spurred to cut back as their bank accounts decline.

Hallucinogens do not seem to have comparable addictive effects. Taking them is not like being a kid on a roller coaster who runs back into the line to ride again as soon as the train coasts to its terminus. The explorer Wade Davis compares the experience of a nose powder used ritually by the Yanomami to being “being shot out of a rifle barrel lined with baroque paintings and landing on a sea of electricity.” I have no idea what this means, but I am certain that the experience is so intense that no normal person would want to get out of the electricity sea, towel off, and stuff himself right back into the rifle barrel. Take enough cannabis, cocaine, or opium, and you’ll sharpen your craving for more. Hallucinogens, however, typically kill off any craving for more hallucinogens for a good amount of time. (Ketamine is an exception, both addictive and able to kill you, if you take too much and choke.)

But what of the possibility that hallucinogens will permanently scramble your brain? As a teenager I heard the tall tale about an acid freak who never came down from his bad trip, and is doomed forever to believe he is an orange. These and similar urban legends do not appear to have been confirmed in the medical literature. But the chances that your trip will be bad, and that you will emerge from your trip shaken and traumatized, are substantial. To make matters worse, hallucinogens tend to warp one’s sense of time, freezing it and making a 10-hour trip feel like a literal eternity, beyond time itself. “Have you ever traveled to the Mountain of Shame and stayed for a thousand years?” Sam Harris, a former psychonaut, once asked. “I do not recommend it.”

Not many people would, I suspect, be so attracted by being shot out of a Rijksmuseum-lined rifle that they would risk a chance of a millennia-long detour in hell. So the appeal of these substances is already limited, and the heedless trippers who use them anyway probably won’t make them into a habit. What of the benefits?