Applying the Prototype Willingness Model to Day-Level Simultaneous Alcohol and Cannabis Use

Objective: The prototype willingness model (PWM) provides a framework for understanding simultaneous alcohol and cannabis use by highlighting important psychosocial (e.g., attitudes, norms) predictors of and pathways (via willingness and/or intentions) to simultaneous use. We examined both the PWM reasoned and social reaction pathways in relation to simultaneous use. Method: Eighty-nine young adults self-monitored alcohol, cannabis, and simultaneous use and related constructs for 30 days via daily assessments. Results: Day-level simultaneous use specific attitudes, norms, perceived vulnerability, intentions, and willingness each predicted simultaneous use, while only day-level intentions and willingness predicted number of negative consequences. We observed significant indirect effects for the two social reaction pathways examined (from descriptive norms to willingness to simultaneous use; from perceived vulnerability to willingness to simultaneous use). Only direct effects were seen for the cognitions in the reasoned pathway; injunctive norms predicted simultaneous use, and attitudes predicted simultaneous use with no mediation by intentions. Conclusions: Findings support applying the PWM to event-level simultaneous use among young adults. Future work should establish if PWM day-level constructs are modifiable targets that may be utilized in intervention work focused on reducing simultaneous use and related harms. Public Health Significance Statement Day-level PWM cognitions including attitudes, norms, perceived vulnerability, intentions, and willingness were found to vary day-to-day and were associated with simultaneous alcohol and cannabis use. Further work is needed to determine if these are proximal modifiable determinants that could be targeted in future interventions.