Rethinking Substance Use Spread in the Platform Era: A Communicable Disease Framework

Substance use has long been understood as spreading through person-to-person transmission. Treatment (secondary and tertiary prevention) is a legitimate priority, but no epidemic, from cholera through COVID-19, has been curtailed by treatment alone. For substance use, prevention infrastructure remains disconnected from the environments in which use now propagates. The communicable disease model, which traces incidence chains and propagation velocity, served heroin outbreak analysis in the 1960s and 1970s but receded as surveillance turned to prevalence estimation. This essay revisits it, as a heuristic, for 2 contemporary cases: cannabis and psychedelics. Both appear to propagate through digital platforms that amplify personal testimony at unprecedented scale, while platform-adapted prevention infrastructure lags. Cannabis normalization appears to have outpaced treatment capacity, with approximately 19 million Americans meeting criteria for cannabis use disorder and service-delivery infrastructure unscaled to that prevalence. Psychedelic use is accelerating amid evolving clinical understanding of its harms. An updated framework anchored in the platform era, pairing transmission cascades with multilevel prevention and health-system response, may supply the primary prevention architecture that populations exposed to commercial and algorithmic promotion now lack. (Am J Public Health. Published online ahead of print November 5, 2026:e1-e7. https://doi.org/10.2105/AJPH.2026.308798).