From the opioid epidemic and medical marijuana to abortion restrictions and physician-assisted suicide, disputes over the proper uses of medicine loom large in American life. Nowhere is this conflict more apparent than in federal drug control policy, which is premised on a clear distinction between legitimate “medical” uses and illicit “abuse.” Yet the Controlled Substances Act defines neither of these foundational concepts. While it is tempting to imagine medicine’s scope is limited to treating or preventing disease — rendering nontherapeutic drug use “abuse” — in fact medical practice has always included interventions that are not aimed at healing. This trend has only accelerated as medical practice has become increasingly consumer-oriented. From Adderall to Xanax, patients now routinely seek prescriptions not to treat diagnosable illnesses, but to relieve stress, improve productivity, and otherwise enhance quality of life.

As physicians increasingly prescribe psychoactive drugs to help healthy people obtain desirable mental states, distinguishing legitimate drug use from recreational abuse becomes ever more difficult. Having failed to acknowledge this challenge, the DEA, courts, and scholars have not offered a principled way to make this distinction, rendering drug control policy increasingly incoherent. As a result, doctors face criminal prosecution without clear standards governing prescribing, potentially valuable interventions are arbitrarily barred from the market, and millions seek the benefits of drugs without professional medical guidance to mitigate their risks.