The COVID-19 outbreak began, precluding further participant recruitment for this protocol, which could only be conducted in-person. A decision was made that ample data was available to end data collection earlier than anticipated.

Impulsivity, a well-known risk factor predicting negative outcomes, refers broadly to a proclivity towards rapid action with a suboptimal regard for future consequences. Importantly, impulsivity is a multidimensional construct incorporating generalized and behavioral facets. However, underlying mechanisms linking facets of impulsivity to high-risk drinking remain uncertain. Such mechanisms, if uncovered, may be more appropriate intervention targets than impulsivity directly.

Similar to impulsivity, subjective response to alcohol (SR), or individual differences in sensitivity to the pharmacologic effects of alcohol, is an established risk factor for alcohol use disorder. Specifically, experiencing heightened rewarding stimulation and dampened aversive sedation from alcohol are related to high-risk drinking. Theory and recent findings indicate SR and impulsivity may be related, suggesting SR may be a mechanism linking facets of impulsivity to high-risk drinking. However, findings linking impulsivity to SR were all from secondary data analyses and most studies reported on only a single measure of impulsivity. For these reasons, an original data collection using laboratory alcohol administration methods is needed to address which facets of impulsivity are related to SR among young adult drinkers and whether these effects manifest while blood alcohol concentrations are increasing or declining.

This study will utilize a laboratory alcohol administration design to investigate whether distinct facets of impulsivity (i.e., generalized, choice, response) are related to subjective responses (i.e., stimulation and sedation) following alcohol administration.

Young adult heavy drinkers, aged 21-30, will enroll in a laboratory alcohol administration study. In a simulated bar laboratory, participants will be administered oral alcohol with three vodka-based drinks. This procedure will allow collection of several measures, notably a widely used, validated measure of self-reported SR and multiple measures capturing facets of impulsive behavior prior to and following alcohol administration. Participants will be recruited through a number of means. Flyers will be posted and handed out in and around the various colleges, universities and technical schools in the Gainesville area as well as in other public areas. The study team will utilize the internet by posting brief solicitation messages on social media, newspaper sites, and classified advertising sites. These same brief messages will also be disseminated to students at the local colleges, universities and technical schools in the area via batch emails and list servs. When permitted, brief recruitment talks will be given verbally during class meetings at these local institutions. Verbal recruitment messages will contain the same material in the appended flyers and other advertisements. Copies of flyers will also be provided at the conclusion of these brief recruitment talks. Potential participants will complete an initial eligibility questionnaire over the phone or online. Participants who appear eligible based on the phone/web screen will be invited to attend an in-person screening appointment. If eligible, participants will be scheduled for two alcohol drinking sessions separated by a minimum of one and a maximum of seven days. After the second drinking session, participants will be scheduled for a follow-up appointment.

Inclusion Criteria:

• Be between the ages of 21-30
• Be able to read English and complete study evaluations
• Drink alcohol regularly
• Be willing to consume vodka-based alcoholic beverages

Exclusion Criteria:

• Have positive urine screen results at the in-person screening or on the day of an alcohol drinking session for illegal drugs
• A woman who is pregnant, nursing, or refuses to use a reliable method of birth control.
• A current undergraduate or graduate student at any level in one of the departments that make up the College of Health and Human Performance (HHP) at the University of Florida (UF), where Dr. Leeman's faculty appointment is.