Summary: New research shows that the belief of “holding your liquor” is more complex than commonly thought, especially for heavy drinkers and people with alcohol use disorder (AUD). While some experienced drinkers appear less impaired after a typical intoxicating dose, their impairment increases substantially when they drink amounts similar to their usual high-intensity consumption—and recovery can remain incomplete hours later.
Researchers at the University of Chicago compared psychomotor and cognitive effects of alcohol across people with different drinking patterns. The findings clarify the limits of behavioral tolerance and highlight risks tied to high-intensity drinking among heavy social drinkers and individuals with AUD.
Key facts:
- After a standard intoxicating dose (about four to five drinks; breath alcohol concentration or BrAC ≈ 0.08–0.09%), people with AUD showed less observed impairment on fine motor and cognitive tests than light drinkers.
- When drinkers with AUD consumed a larger amount consistent with their typical heavy drinking (about seven to eight drinks; BrAC ≈ 0.13%), their psychomotor and cognitive impairment increased dramatically—exceeding the impairment seen in light drinkers after the standard dose.
- Both heavy social drinkers and people with AUD reported feeling less impaired than light drinkers, but objective tests revealed greater performance deficits after drinking amounts aligned with their usual intake.
Source: University of Chicago
Overview
The study offers a more nuanced view of alcohol tolerance. While heavier drinkers can display behavioral tolerance at certain doses, that tolerance has limits. When alcohol consumption reaches the higher levels typical for many with AUD, impairment accumulates and recovery slows, producing greater functional disruption than might be expected from their self-reported tolerance.
Study design and participants
This work is part of the Chicago Social Drinking Project, an ongoing program begun in 2004 that examines how substances such as alcohol affect mood, cognition, and behavior across different drinking patterns. For the present analysis, researchers enrolled three groups of young adults in their 20s categorized by binge drinking frequency: light drinkers (who do not binge), heavy social drinkers (who binge several times a month), and individuals meeting diagnostic criteria for alcohol use disorder who binge frequently (roughly one-third or more days per month).
In controlled laboratory sessions, participants consumed a flavored alcoholic beverage standardized to body weight. The primary “intoxicating” dose equaled roughly 0.8 g/kg (approximately four to five standard drinks), producing peak BrAC near 0.09 g/dL; female participants received 85% of the male dose to approximate sex differences in alcohol metabolism. Drinks were consumed over 15 minutes. Sixty participants with AUD also completed an additional session receiving a higher dose (about 1.2 g/kg, peak BrAC ≈ 0.13 g/dL) that more closely reflected their usual high-intensity drinking.
Performance and self-report measures
Objective performance was assessed at 30, 60, 120, and 180 minutes after drinking using two established tasks: the Grooved Pegboard (a fine motor coordination task where participants place 25 grooved pegs into randomly slotted holes and are scored on completion time) and the Digit Symbol Substitution Task (a timed paper-and-pencil test assessing perceptual-motor processing and psychomotor speed). At 30 and 180 minutes participants also rated their perceived level of impairment from “not at all” to “extremely.” Breath alcohol concentration was measured at each interval.
Main findings
Compared with light drinkers, both heavy social drinkers and people with AUD reported feeling less impaired and showed evidence of greater behavioral tolerance after the 0.8 g/kg dose: peak impairment was lower and recovery to baseline occurred more quickly on the psychomotor tasks. This supports the common observation that frequent drinkers often appear to “hold their liquor” at moderate binge levels.
However, when individuals with AUD consumed the higher 1.2 g/kg dose—closer to their typical drinking episode—their impairment more than doubled relative to the lower dose and surpassed the impairment shown by light drinkers at the 0.8 g/kg level. Importantly, their performance did not return to baseline within the three-hour testing window. In other words, while behavioral tolerance may blunt impairment at moderate intoxication, high-intensity drinking produces additive psychomotor deficits that exceed those of less frequent drinkers and persist longer.
Implications
These results highlight two important points for understanding alcohol-related harm and prevention. First, subjective perceptions of tolerance—feeling less impaired—do not reliably indicate intact psychomotor or cognitive function. Second, tolerance at moderate intoxication does not protect against the cumulative and prolonged impairment that accompanies larger doses typical of high-intensity drinking. That disparity increases the risk of accidents, injuries, and impaired driving among heavy drinkers who may underestimate their actual impairment.
Andrea King, PhD, Professor of Psychiatry and Behavioral Neuroscience at the University of Chicago and senior author of the study, emphasized this “double-edged sword”: heavy drinkers often experience stronger pleasurable effects and cravings that encourage continued drinking, even as impairment mounts. The new findings underline the need for targeted education and treatment for people who engage in high-intensity drinking to reduce alcohol-related accidents and other harms.
The study, titled “Holding your liquor: Comparison of alcohol-induced psychomotor impairment in drinkers with and without alcohol use disorder,” was supported by the National Institute on Alcohol Abuse and Alcoholism and the National Institute on Drug Abuse. Additional authors include Nathan Didier, Ashley Vena, Abigayle Feather, and Jon Grant from the University of Chicago.
About this AUD research news
Author: Matt Wood
Source: University of Chicago
Contact: Matt Wood – University of Chicago
Image: Image credited to Neuroscience News
Original Research: Open access. “Holding your liquor: Comparison of alcohol-induced psychomotor impairment in drinkers with and without alcohol use disorder” by Andrea King et al. Alcoholism: Clinical and Experimental Research
Abstract
Holding your liquor: Comparison of alcohol-induced psychomotor impairment in drinkers with and without alcohol use disorder
Background
Behavioral tolerance suggests that regular drinkers become less sensitive to alcohol’s impairing effects. However, most prior human research has focused on social drinkers, leaving gaps in our understanding of tolerance among heavier drinkers, including those with AUD. This study examines how acute alcohol exposure affects psychomotor performance across different drinking profiles.
Methods
Data from three cohorts of the Chicago Social Drinking Project were analyzed to compare acute alcohol effects on fine motor coordination and perceptual-motor processing in light drinkers (LDs; n = 86), heavy drinkers (HDs; n = 208), and individuals with AUD (AUDs; n = 103). Participants completed the Grooved Pegboard and Digit Symbol Substitution Task before and at multiple times after ingesting either alcohol (0.8 g/kg, peak BrAC ≈ 0.09 g/dL) or placebo across two randomized sessions. Sixty AUD participants completed a third session with a very high dose (1.2 g/kg, peak BrAC ≈ 0.13 g/dL).
Results
Relative to light drinkers, AUD and HD groups reported less perceived impairment and demonstrated greater behavioral tolerance to the 0.8 g/kg dose, evidenced by reduced peak impairment and faster recovery on psychomotor measures. However, AUD participants exposed to the very high dose exhibited more than double the impairment observed after the usual high dose and exceeded impairment levels shown by light drinkers at the 0.8 g/kg dose.
Conclusions
Among these young adult drinkers, heavier drinking patterns correlated with greater behavioral tolerance at a common binge-level dose (0.8 g/kg). Nevertheless, when challenged with very high alcohol doses typical of high-intensity drinking, individuals with AUD experienced substantial and prolonged psychomotor impairment, underscoring the limited protective value of tolerance and the elevated risks of excessive consumption.