Exploring the effects of cannabis health warnings on protective health intentions among US adults in legal recreational states

Background: As cannabis policy trends toward liberalization, assessing cannabis health warning effects becomes increasingly important. This study investigated underlying mechanisms accounting for the effectiveness of cannabis health warnings on protective health intentions. Method: A sample of 1,095 adults (21+) living in legal recreational US states who reported using cannabis in the past 12 months participated in an online experiment. Participants were randomly assigned to view cannabis health warnings that described risks of impaired driving, mental health, and smoke exposure and varied pictures and text (vs. text-only) attributes in warnings. Outcomes were message reactions (cognitive elaboration, fear, and hope), attitudes and beliefs (perceived severity of cannabis harms and perceived susceptibility to cannabis harms, and perceived response and self-efficacy to prevent cannabis harms), and protective health intentions (information-seeking about cannabis health effects and having interpersonal discussions about cannabis harms with family, friends, and medical professionals). Results: MANCOVA results showed no significant differences between text-only vs. pictorial attributes on protective health intentions; thus, warning conditions were controlled and analyzed using structural equation modeling (SEM). SEM results showed that attention to cannabis health warnings (text-only or pictorial) elicited higher cognitive elaboration, fear, and hope-an emotion associated with coping actions that motivate positive expectations of future events. These outcomes, in turn, were associated with greater perceived severity and susceptibility and greater perceived response efficacy, respectively. Hope, perceived severity, and perceived response and self-efficacy were independently associated with greater intentions to seek information about cannabis health effects and to discuss cannabis health harms. Conclusion: Attention to warnings impacted emotions, attitudes, and protective health intentions. Fear is commonly associated with health warning effects, and our results suggest that hope is also an important factor. This research contributes to understanding the effects of cannabis health warnings and can inform regulatory agencies that mandate warnings on cannabis products.