The acute effects of caffeinated versus non-caffeinated alcoholic beverage on driving performance and attention/reaction time
Article first published online: 6 DEC 2010
© 2010 The Authors, Addiction © 2010 Society for the Study of Addiction
Volume 106, Issue 2, pages 335–341, February 2011
How to Cite
Howland, J., Rohsenow, D. J., Arnedt, J. T., Bliss, C. A., Hunt, S. K., Calise, T. V., Heeren, T., Winter, M., Littlefield, C. and Gottlieb, D. J. (2011), The acute effects of caffeinated versus non-caffeinated alcoholic beverage on driving performance and attention/reaction time. Addiction, 106: 335–341. doi: 10.1111/j.1360-0443.2010.03219.x
- Issue published online: 5 JAN 2011
- Article first published online: 6 DEC 2010
- Accepted manuscript online: 6 OCT 2010 11:17AM EST
- Submitted 30 June 2010; initial review completed 7 September 2010; final version accepted 14 September 2010
- energy drinks;
- reaction time
Aims Marketing that promotes mixing caffeinated ‘energy’ drinks with alcoholic beverages (e.g. Red Bull with vodka) targets young drinkers and conveys the expectation that caffeine will offset the sedating effects of alcohol and enhance alertness. Such beliefs could result in unwarranted risk taking (e.g. driving while intoxicated). The aim of this study was to assess the acute effects of caffeinated versus non-caffeinated alcoholic beverages on a simulated driving task and attention/reaction time.
Design We conducted a 2 × 2 between-groups randomized trial in which participants were randomized to one of four conditions: beer and non-alcoholic beer, with and without caffeine added. Caffeine was added in the same proportion as found in a commercially available caffeinated beer (69 mg/12 oz of beer at 4.8% alc. by vol).
Participants Participants were 127 non-dependent, heavy episodic, young adult drinkers (age 21–30) who were college students or recent graduates. The target breath alcohol level was 0.12 g%.
Measures Driving performance was assessed with a driving simulator; sustained attention/reaction with the Psychomotor Vigilance Task (PVT).
Findings Across the driving and attention/reaction time we found main effects for alcohol, with alcohol significantly impairing driving and sustained attention/reaction time, with mainly large statistical effects; however, the addition of caffeine had no main or interaction effects on performance.
Conclusion The addition of caffeine to alcohol does not appear to enhance driving or sustained attention/reaction time performance relative to alcohol alone.