Can self-affirmation and implementation intentions be combined to reduce binge drinking in university students?

Background. Self-affirmation decreases defensive processing of health messages, whereas implementation intentions help people translate positive intentions into behaviour. Combined, they have the potential to reduce binge drinking intentions and behaviour. Methods: UK university students (N=348) reported their typical weekly alcohol use and were randomly assigned to condition in a 2 (self-affirmation) × 2 (implementation intention) between-participants factorial design. All participants read a summary about the health risks of binge drinking. Measures were taken of message derogation, perceived risk, intention and planning. Binge drinking was assessed at one-week follow-up. Findings. Self-affirmed (vs. non-affirmed) participants reported making clearer plans to avoid drinking. No other significant self-affirmation main effects were found. Participants who formed implementation intentions (vs. not) reported drinking fewer units of alcohol and engaging in binge drinking less frequently at one-week follow-up. None of the self-affirmation × implementation intention interactions were significant. Discussion. The present study provides additional evidence for the positive effects of implementation intentions, but only weak evidence for using self-affirmation, to reduce alcohol use in university students.