Summary: A new study has established the first-ever objective, real-time method to detect alcohol-induced blackouts while a person is actively drinking. The research addresses a critical public health obstacle: the historical inability to identify a blackout until the following day, after potential injuries, arrests, or overdoses have already occurred.
Investigators designed a simple, time-delayed memory paradigm that successfully correlates immediate cognitive failure with next-day amnesia, providing a revolutionary tool for real-time risk intervention.
Key Facts
- A Persistent Public Health Hazard: Alcohol-induced blackouts are highly dangerous events explicitly linked to an increased risk of personal injury, legal arrests, physical or sexual assaults, and life-threatening overdoses.
- The In-Situ Breakthrough: To bypass the classic barrier of not knowing when a blackout is actively occurring, researchers had 63 participants complete objective memory tests while they were actively drinking in real-time.
- The 15-Minute Formula: The real-time test requires a drinking individual to view a specific image and then attempt to recall it roughly 15 minutes later. A complete failure to remember the image serves as an immediate, objective indicator of an active blackout state.
- High Negative Predictive Power: Dr. Miller revealed that over 90% of the time, if a participant successfully remembered all the images while drinking, they did not report a blackout the next day. Forgetting an image was found to be moderately correlated with next-day self-reported amnesia.
- The “Friend-Check” Application: While the ultimate objective is to develop a specialized mobile app to accurately diagnose active blackouts, the methodology can be used immediately by social groups. Friends can test each other by assigning something to remember and asking about it 15 minutes later to gauge if an individual requires close monitoring.
- Demographic Limitations: Because the baseline clinical cohort consisted primarily of social-drinking young adults, future testing is required to see if the predictive value shifts in older populations or individuals living with severe alcohol use disorder.
Source: University of Missouri Columbia
It’s not surprising if someone experiences memory loss, or a ‘blackout,’ while drinking alcohol. While common, blackouts are considered a public health concern linked to injury, arrest, assault and overdose.
Given these consequences, the ability to identify and intervene in a blackout could reduce people’s risk for alcohol-related harm.
One researcher from the University of Missouri School of Medicine has developed a way to identify blackouts in real-time. In the study, 63 participants completed memory tests while they were actively drinking. They would view an image, and 15 minutes later, they had to report what they remembered.
Theoretically, not remembering the image would indicate a blackout had occurred. Researchers compared these real-time memory tests of blackout to participants’ self-reported experiences the next day to determine if a blackout happened.
“In our study, not remembering an image while drinking was moderately correlated with next-day self-reports of blackout,” study author Mary Beth Miller said. “In contrast, over 90% of the time, if someone remembered all the images they saw while drinking, they didn’t self-report a blackout the next day.”
These memory tests are a breakthrough in alcohol research, Miller said, and are the first objective measure of alcohol-induced blackouts ever created.
“The biggest barrier to studying blackouts is that you can’t tell when they’re happening,” Miller said. “Being able to identify blackouts in real time will help us figure out when and why they happen.”
The researchers are still testing and building their memory testing tool. Since study participants were mainly social-drinking young adults, it’s possible that different populations, like older adults with alcohol use disorder, may have different results. They also want to see if results change after giving participants more information to remember.
Miller says the goal is to create an app that accurately identifies blackouts, rather than just ruling them out, but friends going out for drinks can still use the same testing method.
“Memory tests are a quick and easy way to gauge your friends’ risk of blackout while you’re out drinking. If you’re worried about your friend, you can just give them something to remember and ask about it roughly 15 minutes later,” Miller said.
“If they don’t remember, it doesn’t necessarily mean they’re blacked out, but I would keep an eye on them. If they do, you might feel a little reassured. They may not be making good decisions, but our data suggests they’ll probably remember those decisions tomorrow.”
Mary Beth Miller, PhD is an associate professor of psychiatry and the Director of the Health Intervention and Treatment Research Laboratory at the Mizzou School of Medicine.
Funding information This work was supported by funding from the University of Missouri’s Center for Addiction Research and Engagement. Investigator effort was supported by the National Institute on Alcohol Abuse and Alcoholism (K23AA026895, T32AA013526).
Key Questions Answered:
A: You can easily see if someone is slurring their speech or stumbling, but you cannot look at a person and tell if their brain has completely stopped recording memories. A person experiencing a blackout can often continue talking, walking, and making decisions, making the condition entirely invisible from the outside. This test provides the first objective tool to peek inside the brain’s recording software in real-time.
A: Not necessarily. Forgetting a single image while drinking is moderately correlated with a blackout, but it isn’t an absolute guarantee. However, it serves as an immediate red flag. If your friend blanks on something they saw just 15 minutes ago, their brain is struggling to process information, meaning it is time to cut them off and keep a very close eye on them.
A: It changes the entire timeline of intervention. Previously, researchers and clinicians could only study blackouts retroactively, asking people the next morning what they remembered. By engineering this into a future smartphone app, the technology can actively intervene before a person suffers an alcohol-related injury, assault, or overdose, moving public health from a position of regret to real-time prevention.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this pharmacology and neurodevelopment research news
Author: Rochita Ghosh
Source: University of Missouri-Columbia
Contact: Rochita Ghosh – University of Missouri-Columbia
Image: The image is credited to Neuroscience News
Original Research: Closed access.
“Predictive value of real-time memory tests in identifying alcohol-induced blackouts in situ” by Mary Beth Miller, Sydney D. Shoemaker, Lindsey K. Freeman, Ashley F. Curtis, Jennifer E. Merrill, Edgar C. Merkle. Addiction
DOI:10.1111/add.70446
Abstract
Predictive value of real-time memory tests in identifying alcohol-induced blackouts in situ
Background and aims
Memory loss from alcohol use (‘blackout’) is a prevalent and costly indicator of substance-related harm. While alcohol-induced blackouts can be assessed retrospectively via self-report, no tool exists to identify blackouts objectively in real time, hindering progress in research as well as intervention efforts.
This study tested the feasibility and diagnostic accuracy of real-time memory tasks in identifying alcohol-induced blackouts in situ.
Design
Prospective diagnostic study.
Setting
United States.
Participants
Young adults (18–30 years of age; n = 63) reporting recurrent memory loss as a result of alcohol use were recruited from across the United States between December 2022 and January 2024.
Measurements
Participants completed a baseline survey and orientation interview, followed by 30 days of ecological momentary assessments (EMA). EMA included recall and recognition tests for visual stimuli during drinking events (index tests) and subsequent self-reports of blackout (reference standard).
At the end of the protocol, participants also completed a Timeline Followback interview of blackout events during the assessment period. Primary outcomes, which were specified prior to data collection, were (a) feasibility of memory task completion during drinking events and (b) diagnostic accuracy of memory tasks in identifying blackout at the event level. Data were analyzed using Bayesian logistic multilevel models.
Findings
Of the 63 participants included [mean age = 23.2, standard deviation (SD) = 3.3; 78% female, 51% White], 38 (60%) self-reported a blackout during the assessment protocol. On average, participants completed 85% of memory tests prompted (SD = 16.42).
Within days, both greater-than-average number of drinks [odds ratio (OR) = 1.74; 95% confidence interval (CI) = 1.41–2.19] and failure of 1 + recall memory test (OR = 15.53; 95% CI = 5.96–36.27) were associated with increased odds of blackout. In model-predicted probabilities, blackout probability was ~0.01 if a person consumed their average number of drinks, ~0.21 if they had five more drinks than average and ~0.34 if they failed 1 + recall test.
Participants self-reported blackout on 39% of the days that they failed 1 + recall memory test (positive predictive value; 95% CI = 30–49); however, they reported not having a blackout on 92% of days that they correctly recalled all memory tests (negative predictive value; 95% CI = 89–95).
Conclusions
Objective measures of alcohol-induced blackout can be implemented in real-life contexts. Failing a visual memory test while intoxicated is not necessarily indicative of blackout; however, correct recall indicates that blackout is highly unlikely.
