Longitudinal analysis for between- and within-person influences of descriptive alcohol drinking norms and attitudes on drinking outcomes.

BACKGROUND

The study aimed to expand on existing research related to the theory of planned behavior (TPB) by exploring both between-person and within-person effects of descriptive norms and attitudes toward moderate and heavy drinking on drinking outcomes, including drinks per week, blackouts, and alcohol-related consequences. While previous studies focus on between-person effects, this study uniquely investigates both between-person effects as well as within-person changes over time, using longitudinal data collected at six points over 12 months.

METHODS

Participants included 484 mandated college students (M = 18.66, SD = 0.758; 55.6% male). Participants completed measures of descriptive drinking norms, attitude toward moderate and heavy drinking, drinking intentions, and drinking outcomes, including drinks per week, blackout, and alcohol-related consequences. Multilevel models were run to examine the unique between-and within-person effects of descriptive drinking norms and attitude toward moderate and heavy drinking on drinking outcomes.

RESULTS

Overall, the results from the multilevel models showed that at the between-person level, descriptive norms were associated with drinks per week, and a more favorable attitude toward heavy drinking was associated with higher weekly alcohol consumption and related consequences. At the within-person level, within-person fluctuations in descriptive norms and attitude toward heavy drinking were associated with higher weekly drinking, blackout, and alcohol-related consequences, while favorable attitude toward moderate drinking were associated with lower odds of blackouts and fewer alcohol-related consequences.

CONCLUSIONS

Attitudes toward drinking, particularly heavy drinking, at both between-person and within-person levels, are strong predictors of alcohol use and its consequences. Furthermore, attitude toward moderate drinking are protective. Interventions promoting a moderate drinking attitude and reducing heavy drinking attitude and descriptive drinking norms will likely be effective in reducing alcohol-related harm.