When college students drink very heavily or to the point of blacking out, they’re more likely to report poorer cognitive functioning the next day, like forgetting someone’s name or having trouble making decisions, according to new research from the University of Oregon.
The findings, published in Alcohol, Clinical and Experimental Research , are important because heavy drinking is common among young adults, yet many don’t realize its negative effects for both the short- and long-term, said one of the study’s lead authors, Ashley Linden-Carmichael , an associate professor in the Department of Counseling Psychology and Human Services in the UO College of Education .
Young adults who drink heavily often assume that once they sober up, everything returns to normal. It doesn’t, the research shows.
“We’re seeing in this study that heavy drinking can affect functioning the next day,” Linden-Carmichael said. “Students could have a harder time with their schoolwork, going to a job or navigating friendships, and that could have big implications for their mental health.”
Young adults age 18-25 report the highest rates of heavy alcohol use among all age groups, and about 5.1 million young adults in the United States met the criteria for alcohol-use disorder in 2023, according to the Substance Abuse and Mental Health Services Administration . About half of young adults who drink reported at least one instance when they drank to the point of blacking out, studies show.
“When someone is blacking out, they’re continuing to navigate the world, but they’re not processing information or making and storing memories, which can lead to making decisions they normally wouldn’t, increasing the risk for physical injury and sexual assault,” Linden-Carmichael said.
Linden-Carmichael, who is also part of the UO’s Prevention Science Institute , co-authored the study with Jacqueline Mogle of RTI Health Solutions in North Carolina. Other researchers included Jennifer Shipley, also with the Prevention Science Institute, and Sara Miller and Stephen Wilson, both with Penn State University.
The researchers wanted to explore this subject after they saw another research team’s study that included scans showing short-term impacts on the brains of young adults who drank heavily at a 21st birthday event. The effects on the brain were even more pronounced if the person had blacked out.
“We wanted to know whether young people were aware of these effects and if they actually noticed any changes in their cognitive functioning after a night of heavy drinking,” Linden-Carmichael said.
The UO study is the first to track participants over several weeks, surveying them on their cognitive functioning the day after consuming no alcohol, a moderate amount or a large amount. Participants reported their memory lapses, difficulties paying attention or problems making decisions the day after drinking heavily, some to the point of blacking out.
Those moments of self-realization could one day be an ideal time to deliver personalized health education or motivational messages, known as “just-in-time interventions,” through an app to a person’s mobile phone, Linden-Carmichael said. The intervention could provide real-time feedback and help participants connect their current cognitive struggles with yesterday’s heavy drinking, she said.
The researchers appreciated participants’ extensive level of involvement in the study, which set it apart from previous efforts, Linden-Carmichael said.
Prior studies on heavy drinking by young adults tended to follow them for a week or so. The UO study took a longer view, examining drinking on one day and cognitive functioning the next for 304 college students over a 21-day period between November 2023 and May 2024.
To enroll in the study, students had to report a history of heavy drinking at least twice in a typical month and at least one instance in the past year of blackout drinking, defined as not remembering what they did during a drinking episode. Heavy drinking was defined as consuming at least four drinks in a sitting for women and five for men.
The study included both subjective and objective measures of cognition. Each day, researchers texted participants with surveys every two hours between 11 a.m. and 5 p.m., asking them to report the previous day’s happenings, and their current temperament and cognition. They had an hour to complete each survey plus a “brain game,” or cognitive task. In one task, participants tried to recall increasingly longer strings of numbers in the reverse order that they had been presented. Participants were scored based on how many numbers they recalled correctly.
The researchers found that any alcohol consumption was linked to a 14% greater likelihood of cognitive lapses the next day compared with no drinking, and each additional drink on a given day was associated with a 5% increase in likelihood of cognitive lapses the next day.
“But the biggest effects were when they drank at very high levels, or when they were blacking out,” Linden-Carmichael said.
High-intensity drinking, more than eight drinks in a sitting for women, or 10 for men, was associated with twice the likelihood of reporting cognitive lapses the next day. Blackout drinking was linked to a 40% greater likelihood of cognitive lapses the next day.
Linden-Carmichael next hopes to examine the role of sleep as a protective factor for young adults who drink heavily or black out and to explore the cognitive effects after consecutive days of heavy drinking or blacking out. She also is conducting research on the effects on young adults of using alcohol and cannabis together.
— By Sherri Buri McDonald, University Communications
High-intensity and blackout drinking impact on next-day cognitive functioning among college-attending young adults
25-Mar-2026