The legalization and decriminalization movements for cannabis have spread from a handful of pioneering jurisdictions to much of the developed world over the past decade.

Psychedelic-assisted therapy — using psilocybin, MDMA, ketamine, and other substances in clinical settings — has moved from fringe experimentation to mainstream psychiatric medicine.

The opioid crisis in North America continues to evolve, with harm-reduction approaches gaining ground against purely abstinence-based policies.

In this context, evidence that humans have been using psychoactive substances for at least 25,000 years — long before any of the social conditions to which drug use is sometimes attributed — arrives with a particular resonance.

It suggests that the impulse to seek altered states is not a product of modernity’s problems.