State cannabis laws and digital advertising exposure drive young adult cannabis and delta-8 THC use through shifts in risk perceptions and use motives.
Cannabis policy researchers, advertising regulators, public health communication specialists
What the researchers found
Legal cannabis states saw lower DICP use motives but higher cannabis-only use frequency. More restrictive delta-8 laws increased cannabis-only (vs. both) use. Digital cannabis ads lowered risk perceptions and increased use, motives, intentions, and consequences. These associations were mediated by use motives and risk perceptions. Higher use frequency mediated associations with consequences.
Why it matters
This is among the first studies to trace the full causal chain from cannabis policy and marketing through psychological mechanisms to actual use behavior and consequences — showing exactly how and why these upstream factors affect downstream harm.
The numbers in context
3,437 participants across two waves. Legal vs. illegal states: lower DICP motives, higher cannabis-only use. Digital ads associated with lower risk perceptions, higher use motives, higher use intentions, more consequences. Frequency mediated law/advertising effects on consequences.
How the study worked
Two-wave longitudinal survey (2023-2024) of 3,437 US young adults aged 18-34 (~50% past-month cannabis use by design). Multivariable regressions with parallel mediation assessed direct and indirect associations across state laws, advertising exposure, risk perceptions, motives, use, and consequences.
What this study cannot tell us
Self-reported survey data. ~50% past-month cannabis user sampling design may overrepresent users. State law assignment is cross-sectional even with longitudinal individual data. Digital ad measurement may not capture total exposure.
How to read the evidence
Longitudinal design with mediation analysis and large sample provides strong correlational evidence, though observational design limits causal conclusions.
When this study was published
Published 2026 with 2023-2024 longitudinal data, capturing the rapidly evolving DICP market.
The bigger picture
The mediation through risk perceptions and motives suggests that how young adults think about cannabis — not just access — drives behavior. This means counter-advertising and education could be as important as legal restrictions.
Questions still open
- Could counter-messaging campaigns effectively raise risk perceptions? Do delta-8 restrictions push users to unregulated markets? Would standardized cannabis marketing regulations reduce use consequences?
Common questions
Do cannabis laws actually affect how much people use?
Does cannabis advertising influence use?
Read the original research
A longitudinal mediated examination of legal, commercial, and individual determinants of cannabis and derived cannabis use behaviors and consequences among US young adults.
Addictive behaviors, 172, 108526
Citation
LoParco, Cassidy R; Rossheim, Matthew E; Wang, Yan; Yang, Y Tony; Paichadze, Nino; Cavazos-Rehg, Patricia A; Berg, Carla J. (2026). A longitudinal mediated examination of legal, commercial, and individual determinants of cannabis and derived cannabis use behaviors and consequences among US young adults.. Addictive behaviors, 172, 108526. https://doi.org/10.1016/j.addbeh.2025.108526