Daily Level Examination Indicates That Positive Affect, But Not Negative Affect, Is Associated With Alcohol and Marijuana Use Among Adolescents and Young Adults

Objective: Although there is growing evidence that alcohol use at the daily level is associated with positive but not negative affect, results are mixed when examining marijuana use and simultaneous alcohol and marijuana (SAM) use (i.e., use with overlapping effects). In addition, less is known about these daily level associations among diverse samples of adolescents and young adults. The present study will address these gaps. Method: Participants (N = 1,006; 57.3% female, 43.1% White, Non-Hispanic, ages 15−25; Mage = 20.0) were part of a study on substance use that consisted of a 3-week ecological momentary assessment (EMA) burst design (eight surveys per week, up to 2×/day) that was repeated quarterly over a 12-month period. Results: Within-person results indicated that on days with elevated positive affect, participants reported consuming more drinks, whereas positive affect was not significant for hours high from marijuana. In addition, on days with elevated negative affect, participants reported fewer hours high from marijuana. No association was found between negative affect and number of drinks. Finally, within-person results indicated that on alcohol or marijuana days with elevated positive affect, individuals were more likely to report SAM use. There was no association found between negative affect and SAM use. Conclusions: Results have implications such that in-the-moment interventions for alcohol and SAM use may be more salient when individuals have higher positive affect than average, whereas such interventions may be more relevant for marijuana use when negative affect is lower compared to average levels. Public Health Significance Statement On days when adolescents and young adults experienced stronger positive affect, they consumed more drinks but did not spend more hours high from marijuana, whereas on days when they experienced stronger negative affect, participants reported fewer hours high from marijuana but did not consume more drinks. In addition, on days when participants used alcohol or marijuana and had higher positive affect, but not negative affect, they were more likely to report simultaneous alcohol and marijuana (SAM) use. Results suggest in-the-moment interventions for alcohol and SAM use may be more salient when adolescents and young adults have higher than average positive affect, whereas such interventions may be more relevant for marijuana use when negative affect is lower compared to average levels.