Perception of intoxication following alcohol and energy drink consumption

Introduction and Aims: Alcohol and energy drink (AED) ingestion is thought to impair assessment of intoxication. Several studies have evidenced lower subjective intoxication ratings post-AED consumption relative to alcohol consumption, despite similar objective performance outcomes. However, this pattern of results has not been consistently recorded between studies and across subjective measures. Consequently, the current study was designed to investigate the impact of AED ingestion on several subjective intoxication measures. Design and Method: Using a single-blind, placebo-controlled, crossover design, 24 participants completed the Biphasic Alcohol Effects Scale (BAES), Desire-for-Drug scale, and a subjective effects scale 30 and 125 minutes after receiving: 0.5 g/kg alcohol, 3.57 ml/ kg Red Bull energy drink, AED and placebo. Results: Blood alcohol concentration did not differ signifi cantly for AED and alcohol conditions. Preliminary analyses revealed that participants recorded higher ratings on psychological (i.e. BAES Sedation subscore) and physiological (e.g. dizziness, nausea, slurred speech, decreased co-ordination) sedation-related outcomes following active alcohol ingestion relative to placebo. Furthermore, ratings of intoxication, impairment, mental fatigue, and feeling the drink’s effects were signifi cantly higher in active alcohol conditions compared to placebo. BAES stimulation ratings were higher in active alcohol conditions relative to placebo at pre-testing, and in active energy drink conditions relative to placebo at post-testing. However, no effect of energy drinks was evident on stimulation-related physiological outcomes or other intoxication measures. Discussion and Conclusion: Previous conclusions of impaired intoxication post-AED consumption are generally not supported by the present study, as perceived intoxication was generally greater in all alcohol conditions, with no signifi cant difference between alcohol and AED sessions.