A standard argument for outlawing drugs is that such substances are “addictive.” As a matter of science, this claim is often over‐​stated: using alcohol, caffeine, cigarettes, or heroin a few times does NOT generate physiological or psychological dependence; such effects kick in only after repeated, long‐​term use (and even then, far from universally). That said, all these substances — and many more — can indeed be addictive.


But a crucial question is: so what? Take the caffeine example. Hundreds of millions of people around the globe — perhaps billions — are addicted to tea, coffee, or diet coke, yet few consider this an issue for health or policy. Why? Because long‐​term, heavy use of caffeine does not seem to have major undesired side effects. Indeed, much of the world celebrates its coffee and tea habit, praising the culinary enjoyment and social interaction that accompanies or even arises from this addiction.


So for those who believe government should ban “harmful products,” the question should not be whether a substance is addictive but whether long‐​term, heavy use harms health, productivity, or other aspects of life. I will not discuss this issue here for alcohol, tobacco, or heroin, other than to suggest that the two substances with the worst sides effects from regular use (cirrhosis for alcohol and lung cancer for cigarettes) are currently legal while heroin, with much less obvious or dramatic side effects, is not. So much for rational public policy.


Instead, as illustration of misguided thinking about addiction, consider this passage from a recent New York Times article:

DELRAY BEACH, Fla. — Three shaky months into recovery from heroin addiction, Dariya Pankova found something to ease her withdrawal. A local nonalcoholic bar sold a brewed beverage that soothed her brain and body much as narcotics had. A perfect solution — before it backfired.

Ms. Pankova grew addicted to the beverage itself. She drank more and more, awakened her cravings for the stronger high of heroin, and relapsed. Only during another stay in rehab did Ms. Pankova learn that the drink’s primary ingredient, a Southeast Asian leaf called kratom, affects the brain like an opiate and can be addictive, too.

Nowhere does the article cite evidence that Kratom addiction has large or common side effects; rather, the article takes as given that addiction is undesirable per se. That makes no sense, as the caffeine example shows.

So if some people prefer Kratom addiction to heroin addiction — or vice versa — why should policy interfere?