This exploratory study explored the sequential mediation effect of the cognitive pathways through which perceived effectiveness of a drug abuse prevention campaign video influence the intention to share the campaign and to engage in preventive behavior, mediated by first-person perception, third-person perception, and risk perception. This cognitive pathway was analyzed using a sequential mediation model. To test this model, an online survey was conducted with a quota sample of 500 male and female in their 20s and 30s. The findings showed positive relationships between perceived effectiveness of the campaign video and first- and third-person perception, risk perception, sharing intention, and preventive behavior intention. In the sequential mediation model, the path mediated by first-person perceptions was significant for sharing intention. In the case of behavioral intention, only the sequential mediation path via first-person perception showed a significant effect, and when third-person perception was used, only a simple mediation effect was found. Practical implications are discussed, suggesting strategies to enhance campaign’s perceived effectiveness and message composition. Theoretically, this study contributes in that it explored the behavioral component of the third-person effect, a topic previously under-explored, and examined cognitive pathways through a sequential mediation model.