Combined Effects of Alcohol and Caffeine
The purpose of this study is to investigate the effects of caffeine on the self-administration of alcohol. The study will also examine the combined effects of alcohol and caffeine on behavioral performance, participant ratings of behavioral performance, and self-reported subjective effects.
Alcohol or Other Drugs Effects
Drug: Alcohol + Caffeine Beverage
Drug: Alcohol + Caffeine-placebo
|Study Design:||Endpoint Classification: Pharmacodynamics Study
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Outcomes Assessor)
Primary Purpose: Basic Science
|Official Title:||Combined Effects of Alcohol and Caffeine|
- Total beverage consumed [ Time Frame: Measured during 2.5 hour drinking period ] [ Designated as safety issue: No ]The primary outcome measure is the total volume of beverage consumed during alcohol + caffeine sessions and alcohol + caffeine-placebo sessions.
- Circular Lights Task [ Time Frame: Approximately every 30 minutes of the 5.5 hour study period ] [ Designated as safety issue: No ]The Circular Lights Task is a measure of behavioral performance
- The Biphasic Alcohol Effects Scale [ Time Frame: Approximately every 30 minutes of the 5.5 hour study period ] [ Designated as safety issue: No ]The Biphasic Alcohol Effects Scale (BAES: Martin et al., 1993) will be repeatedly administered to assess changes in subjective alcohol effects over time. This measure is a commonly used 14-item scale that assesses stimulant (7 items) and sedative (7 items) subjective effects of drugs on a 10-point likert scale
- Expired air breath alcohol measures [ Time Frame: Approximately every 30 minutes during the 5.5 hour study period ] [ Designated as safety issue: No ]Breath alcohol measures will be taken repeatedly in order to assess blood alcohol levels, as well as assure safe discharge. In order to prevent mouth alcohol contamination of breath alcohol measurements, participants will be required to abstain from drinking for 5 minutes before each measurement and to rinse their mouth out thoroughly with water immediately before breath alcohol measures.
- Subjective ratings 9-point likert scale [ Time Frame: Approximately every 30 minutes during the 5.5 hour study period ] [ Designated as safety issue: No ]
The following three questions will be asked on a 9-point likert scale:
- How much do you like the beverage you have been drinking today?
- Rate your sense of "well-being" right now.
- How much money would you be willing to pay for a standard mixed drink serving (e.g., 8 oz.) of this beverage at a bar?
- Subjective ratings visual analogue scale [ Time Frame: Approximately every 30 minutes during the 5.5 hour study period ] [ Designated as safety issue: No ]
The following two questions will be answered on a visual analogue scale:
- How much do you want another drinking right now?
- How intoxicated do you feel?
|Study Start Date:||January 2011|
|Estimated Study Completion Date:||December 2014|
|Estimated Primary Completion Date:||December 2014 (Final data collection date for primary outcome measure)|
Experimental: Alcohol self-administration
All participants will participate in seven sessions. In three sessions, each participant will consume a beverage containing alcohol and caffeine. In three separate sessions, participants will consume a beverage containing alcohol and caffeine-placebo. In the final session, all participants may choose which beverage they consume. Participants and research assistants will be blinded to inclusion of caffeine/caffeine-placebo in beverage, but each beverage will be labeled for identification (e.g., A or B).
Drug: Alcohol + Caffeine Beverage
14 g alcohol per 180 ml total beverage combined with 60 mg caffeine per 180 ml total beverage. The alcohol and caffeine will be mixed in a fruit punch beverage. Participants may self-administer as much beverage as they like with several constraints to assure safety (e.g., participants must stop drinking if their blood alcohol content is above .12 g/dl).
Other Names:Drug: Alcohol + Caffeine-placebo
14 g alcohol per 180 ml total beverage combined with 2.2 mg quinine per 180 ml total beverage. The alcohol and quinine will be mixed in a fruit punch beverage. Participants may self-administer as much beverage as they like with several constraints to assure safety (e.g., participants must stop drinking if their blood alcohol content is above .12 g/dl).
The purpose of this study is to examine the effects of caffeine on alcohol self-administration. Volunteers will participate in 7 experimental sessions in which they will be given the opportunity to self-administer an alcohol + caffeine or alcohol + caffeine-placebo beverage. The first 6 sessions will involve exposure to the two beverage conditions in mixed order three times each (e.g., A, B, B, A, A, B). The seventh session will be a choice session in which the participant will make a single choice at the beginning of the session about which beverage they will consume that day. In addition to the primary outcomes of quantity of alcohol self-administered and beverage choice, three additional outcomes will be measured including: 1). indirect measures of reinforcing effects (e.g. subjective ratings of liking, well-being, take again); 2). an alcohol-sensitive behavioral measure; and 3). participant ratings of degree of behavioral impairment.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01289561
|United States, Maryland|
|Behavioral Pharmacology Research Unit|
|Baltimore, Maryland, United States, 21224|
|Principal Investigator:||Roland R Griffiths, Ph.D.||Johns Hopkins University|