Natural environment assessment of alcohol responses in risky drinkers

PROJECT SUMMARY ABSTRACT Laboratory alcohol challenges have provided important knowledge about individual responses to alcohol and risk for drinking-related problems. However, this approach is time- and resource-intensive and cannot fully capture real-world alcohol responses. Therefore, the MPI propose developmental work on a method for

assessing ambulatory alcohol responses that combines smartphone-based high-resolution ecological momentary assessment (HR-EMA) with new-generation, wrist-worn alcohol biosensors (BACTrack Skyn™) to provide objective verification of alcohol use. The over-arching goal of this developmental R21 proposal is to

compare HR-EMA-derived real-time responses during typical heavy drinking episodes in the natural environment in individuals across the alcohol use continuum, including alcohol use disorder (AUD) drinkers, who have largely been excluded from such research, as well as heavy social drinkers (HD) and light drinker

controls (LD). The proposed research will include smartphone assessments throughout a typical drinking episode in participants’ natural environment as well during a comparison non-alcohol drinking beverage consumption episode assessed at approximately the same time but on a different day. Participants will

complete brief 1-minute smartphone-based surveys at multiple time points during their drinking episodes to assess their quantity consumed, subjective responses, and contextual events. They will also complete brief daily mood surveys and next-day surveys after the drinking episodes to assess carry-over effects and

consequences. The noninvasive wrist-worn sensor will be used during, and for 12 hours after, each drinking episode as objective verification of self-report behavior. The study will enroll 105 participants (35/per subgroup) between ages 21-55 for participation over an approximate one-week interval. We conservatively anticipate up

to a 15% drop-out rate in order to have a final N=90 participants. Our first aim is to compare acute subjective responses during alcohol drinking episodes in the natural environment across drinker subgroups. We predict that alcohol will produce higher stimulation, liking, and wanting in AUD and HD than in LD, particularly early in

the drinking episode (i.e., first hour) and greater reduction in anxiety and stress in AUD versus HD and LD, after controlling for amount consumed and non-alcohol drinking episode responses. We also predict that wearable biosensors will be acceptable (≥85% use, few losses or damage) and show good sensitivity and

specificity detect alcohol use vs. non-use in >90% of episodes. Our second aim is to examine individual differences in acute alcohol responses as a function of drinking pace. We predict that faster-paced alcohol consumption will be positively associated with stimulation and wanting and inversely associated with sedation,

and these effects will be most pronounced in AUD vs LD, with HD intermediate. In sum, the proposed research will advance the alcohol research field by expanding HR-EMA methodologies to assess natural environment acute drinking behavior, subjective response, and drinking-related outcomes in diverse, clinically-relevant

drinker subgroups.