Cited by 78Coffee research and impactsSubstance Abuse Treatment and OutcomesAlcohol Consumption and Health Effects

The combined effects of alcohol, caffeine, and expectancies on subjective experience, impulsivity, and risk-taking.

Open access
Heinz, Adrienne J., de Wit, Harriet, Lilje, Todd C., Kassel, Jon D.·2013·Experimental and Clinical Psychopharmacology

Abstract

Caffeinated alcoholic beverage (CAB) consumption is a rapidly growing phenomenon among young adults and is associated with a variety of health-risk behaviors. The current study examined whether either caffeinated alcohol or the expectation of receiving caffeinated alcohol altered affective, cognitive, and behavioral outcomes hypothesized to contribute to risk behavior. Young adult social drinkers (N = 146) participated in a single session where they received alcohol (peak Breath Alcohol Content = .088 g/dL, SD = .019; equivalent to about four standard drinks) and were randomly assigned to one of four further conditions: 1) no caffeine, no caffeine expectancy, 2) caffeine and caffeine expectancy, 3) no caffeine but caffeine expectancy, 4) caffeine but no caffeine expectancy. Participants' habitual CAB consumption was positively correlated with measures of impulsivity and risky behavior, independently of study drugs. Administration of caffeine (mean dose = 220 mg, SD = 38; equivalent to about 2.75 Red Bulls) in the study reduced subjective ratings of intoxication and reversed the decrease in desire to continue drinking, regardless of expectancy. Caffeine also reduced the effect of alcohol on inhibitory reaction time (RT) (faster incorrect responses). Participants not expecting caffeine were less attentive after alcohol, whereas participants expecting caffeine were not, regardless of caffeine administration. Alcohol decreased response accuracy in all participants except those who both expected and received caffeine. Findings suggest that CABs may elevate risk for continued drinking by reducing perceived intoxication, and by maintaining the desire to continue drinking. Simply expecting to consume caffeine may reduce the effects of alcohol on inattention, and either expecting or consuming caffeine may protect against other alcohol-related performance decrements. Caffeine, when combined with alcohol, has both beneficial and detrimental effects on mechanisms known to contribute to risky behavior.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1037/a0032337

Cites

86 of 86 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Some studies have indicated detrimental effects of l-theanine on reaction times and numerical working memory and of caffeine on inhibitory control.

    “Yet, some studies have indicated detrimental effects of l-theanine on reaction times and numerical working memory27,35 and of caffeine on inhibitory control32.”

    From Effects of l-theanine–caffeine combination on sustained attention and inhibitory control among children with ADHD: a proof-of-concept neuroimaging RCT (2020) · cites this paper as [32]

    The Results (Other Experimental Measures; page unavailable) found that caffeine with alcohol was associated with less hesitation on trials where participants failed to inhibit a response. But caffeine did not affect stop-signal reaction time, the study’s measure of inhibitory ability. The Discussion describes a possible detrimental effect on inhibition, while acknowledging that caffeine may simply have sped responses; the citation therefore overstates the finding. (LLM, conf=0.86)

    Experimental — accuracy not yet measured
  • Caffeine administration is associated with an acute reduction of impulsivity in Spontaneous Hypertensive Rats and alcohol-associated impulsivity in healthy adults.

    “Furthermore, administration of caffeine was associated with an acute reduction of impulsivity in Spontaneous Hypertensive Rats, an animal model of ADHD31 and also the alcohol-associated impulsivity in healthy adults32.”

    From Effects of l-theanine–caffeine combination on sustained attention and inhibitory control among children with ADHD: a proof-of-concept neuroimaging RCT (2020) · cites this paper as [32]

    The Discussion (page not provided) says that expecting or consuming caffeine may reduce inattention, an index of impulsivity, in the alcohol experiment. But it also reports no improvement in inhibition from caffeine consumption and concludes that caffeine has no direct, uniform effect on impulsive behavior under alcohol. The rat finding is attached to a different citation, so this verdict concerns only the claim about adults. (LLM, conf=0.86)

    Experimental — accuracy not yet measured
  • The data on alcohol-mixed energy drinks are equivocal, with studies showing that caffeine combined with alcohol does not always increase the amount of alcohol consumed or does not have an impact on risk taking behavior.

    “These data are equivocal, however, with studies showing that caffeine combined with alcohol does not always increase the amount of alcohol consumed (240) or does not have an impact on risk taking behavior (235, 241).”

    From The Safety of Ingested Caffeine: A Comprehensive Review (2017) · cites this paper as [241]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 3

  1. Kramer A Spinks J Jennings JR Coles MGH Capacity views of human information processing Handbook of cognitive psychophysiology: Central and autonomic nervous system approaches 1991 New York John Wiley 179 249
  2. Rohsenow DJ Howland J Caffeinated alcohol beverages: Attractive misunderstood danger for young adults The Brown University Digest of Addiction Theory and Application 11 8 2007 PMC2873210 20490367
  3. Sobell LC Sobell MB Litten RZ Allen JP Timeline followback: A technique for assessing self-reported alcohol consumption Measuring alcohol consumption: Psychosocial and biochemical methods 1992 Totowa, NJ Humana Press 41 72

Cited by

Sorted by citations

Authors
Heinz, A. J., de Wit, H., Lilje, T. C., & Kassel, J. D.
Affiliations
  • VA Palo Alto Health Care System (US)
  • Uniformed Services University of the Health Sciences (US)
  • University of Illinois Chicago (US)
Venue
Experimental and Clinical Psychopharmacology
Published
2013
Volume
21
Issue
3
Pages
222-234
ISSN
  • 1064-1297 (ISSN-L)
  • 1936-2293
OpenAlex
W2057829605
Cited by
78
References
86
Citations by year
2025: 5 · 2024: 2 · 2023: 8 · 2022: 5 · 2021: 5 · 2020: 5 · 2019: 6 · 2018: 7 · 2017: 7 · 2016: 8 · 2015: 7 · 2014: 11 · 2013: 2
FWCI
6.87
Type
journal article
Language
en
Open access
Locations
  • Experimental and Clinical Psychopharmacology (publishedVersion)
  • PubMed (publishedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
Funders
  • University of Illinois at Chicago
  • National Institute on Alcoholism and Alcohol Abuse (F31 (AA018918))
  • VA Office of Academic Affairs
  • Health Services Research and Development
Topics
  • Health Sciences › Medicine › Pharmacology › Coffee research and impacts
  • Health Sciences › Medicine › Epidemiology › Substance Abuse Treatment and Outcomes
  • Health Sciences › Medicine › Pathology and Forensic Medicine › Alcohol Consumption and Health Effects
Keywords
subjective intoxication, impulsivity, risk-taking, inattention
MeSH terms
Adult, Ethanol, Caffeine, Double-Blind Method, Drug Synergism, Female, Humans, Impulsive Behavior, Male, Risk-Taking, Young Adult

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review