Assessing real-time positive subjective effects of alcohol using high-resolution ecological momentary assessment in risky versus light drinkers

Background: High-resolution ecological momentary assessment (HR-EMA) can assess acute alcohol responses during naturalistic heavy drinking episodes. The goal of this study was to use HR-EMA to examine drinking behavior and subjective responses to alcohol in risky drinkers (moderate-severe alcohol use disorder [MS-AUD], heavy social drinkers [HD]) and light drinkers (LD). We expected that risky drinkers would endorse greater alcohol stimulation and reward, with lower sedation, than LD, even when controlling for amount of alcohol consumed.

Methods: Participants (N = 112; 54% male, M ± SD age = 27.2 ± 4.2 years) completed smartphone-based HR-EMA during one typical alcohol drinking occasion and one non-alcohol-drinking occasion in their natural environment. Participants were prompted to complete next-day surveys that assessed drinking-related outcomes, study acceptability, and safety.

Results: HR-EMA prompt completion rates were excellent (92% and 89% for the alcohol and nonalcohol episodes, respectively). The MS-AUD group consumed the most alcohol with the highest estimated blood alcohol concentration (eBAC) by the end of the alcohol drinking episode (0.14 g/dL) versus LD (0.02 g/dL), with HD intermediate (0.10 g/dL). Relative to LD, MS-AUD and HD endorsed greater positive effects of alcohol (stimulation, liking, and wanting).

Conclusions: This study is the first to use HR-EMA to measure and compare real-world acute alcohol responses across diverse drinker subgroups, including persons with MS-AUD. Results demonstrate that risky drinkers experience heightened pleasurable effects measured in real-time during natural-environment alcohol responses. Rather than drinking excessively to eventually achieve desirable subjective effects, risky drinkers show sensitivity to positive alcohol effects throughout a heavy drinking episode.