Planned Versus Unplanned Drinking and Cannabis Use: Do Facets of Trait Impulsivity Influence Daily Risk?

Objective: Planned and unplanned substance use have been examined as predictors of heavier alcohol and cannabis use and problems at the between-person level. However, it remains unclear whether planned versus unplanned use is riskiest at the day-level, and for whom. The present study tested whether day-level planned versus unplanned alcohol and cannabis use were associated with higher alcohol and cannabis consumption and negative consequences that day and whether two impulsive traits, lack of premeditation and positive urgency, moderated associations. Method: Young adults (N = 409; 50.9% female) completed five bursts of daily surveys, each consisting of a morning and afternoon report across 14 consecutive days. During a baseline session, participants reported their impulsivity (UPPS-P). During afternoon surveys, participants reported their plans to use alcohol/cannabis that night. During morning surveys, participants reported number of drinks consumed/hours spent high yesterday and negative consequences experienced. Results: Planned drinking days were associated with a greater number of drinks and negative consequences, whereas planned cannabis use days were associated with more hours spent high but not negative consequences. In the drinking quantity model, there was a significant interaction for planned versus unplanned drinking by positive urgency. Planned drinking was associated with heavier alcohol consumption across levels of positive urgency; however, unplanned drinking was associated with heavier consumption for individuals with higher (vs. lower) levels of positive urgency. Conclusions: Day-level planned drinking and cannabis use are important factors to target in just-in-time interventions. However, interventions focused on planned and unplanned drinking may be particularly effective for individuals with higher levels of positive urgency. Public Health Significance Statement The present study found that planned (vs. unplanned) drinking was associated with heavier drinking and negative alcohol consequences and that planned (vs. unplanned) cannabis use was associated with heavier cannabis consumption. However, individuals with higher levels of positive urgency reported consuming more drinks on unplanned drinking days compared to individuals at lower levels of positive urgency. Findings inform event-level theories of risk for negative outcomes and may have implications for just-in-time interventions.