Intoxication‐Related Alcohol Mixed with Energy Drink Expectancies Scale: Initial Development and Validation

Background Young adult use of alcohol mixed with energy drinks (AmEDs) has been linked with elevated risks of a constellation of problem behaviors. These risks may be conditioned by expectancies regarding the effects of caffeine in conjunction with alcohol consumption. The aim of this study was to describe the construction and psychometric evaluation of the Intoxication‐Related AmED Expectancies Scale (AmED_EXPI), 15 self‐report items measuring beliefs about how the experience of AmED intoxication differs from the experience of noncaffeinated alcohol (NCA) intoxication. Methods Scale development and testing were conducted using data from a U.S. national sample of 3,105 adolescents and emerging adults aged 13 to 25. Exploratory and confirmatory factor analyses were conducted to evaluate the factor structure and establish factor invariance across gender, age, and prior experience with AmED use. Cross‐sectional and longitudinal analyses examining correlates of AmED use were used to assess construct and predictive validity. Results In confirmatory factor analyses, fit indices for the hypothesized 4‐factor structure (i.e., Intoxication Management [IM], Alertness [AL], Sociability [SO], and Jitters [JT]) revealed a moderately good fit to the data. Together, these factors accounted for 75.3% of total variance. The factor structure was stable across male/female, teen/young adult, and AmED experience/no experience subgroups. The resultant unit‐weighted subscales showed strong internal consistency and satisfactory convergent validity. Baseline scores on the IM, SO, and JT subscales predicted changes in AmED use over a subsequent 3‐month period. Conclusions The AmED_EXPI appears to be a reliable and valid tool for measuring expectancies about the effects of caffeine during alcohol intoxication. Use of alcohol mixed with energy drinks (AmEDs) is linked with elevated risks for a constellation of problem behaviors. These risks may be conditioned by expectancies regarding the effects of AmED intoxication. In this study, we introduced a new instrument, the four‐factor Intoxication‐Related AmED Expectancies Scale (AmED_EXPI). Confirmatory factor analysis demonstrated the AmED_EXPI to be psychometrically reliable, and its utility was confirmed by prospectively predicting initiation or continuation of AmED use in a diverse national sample of U.S. young adults.