The authors of a new study have identified three factors responsible for the so-called alcohol blackout, the most common consequence of drinking alcohol when a person experiences memory lapses.
A team of scientists from the Edna Bennett Pierce Center for Prevention Research and the Department of Biobehavioral Health at the University of Pennsylvania in the United States set out to find out whether the way people drink alcohol predicts alcohol-induced memory lapses. They reported their findings in an article for the journal Alcoholism: Clinical and Experimental Research.
Memory impairment is a common consequence of alcohol consumption: according to a 2022 study, approximately 80% of 1700 college students reported at least one episode of blackout. At the same time, the drinker remains conscious (up to a certain point), interacts with others, and in the morning partially or completely does not remember what happened in the evening.
In addition to the periods of amnesia itself, a person may also experience symptoms of mental and behavioral disorders in the context of alcohol consumption. Therefore, understanding the causes of such memory lapses will help prevent harm from alcohol abuse.
The authors of previous scientific studies have concluded that the amount of alcohol consumed is not the only factor that causes memory loss. To find out other reasons and not rely only on self-reports of the people surveyed, American scientists used BACtrack Skyn wrist transdermal alcohol concentration sensors. They measure biomarkers of intoxication in real time.
The study involved 79 students from a large university in the northeastern United States who were prone to “risky” drinking, aged 18 to 22. Everyone took a short baseline survey and visited the lab, where they were given sensors to wear from 5 p.m. on Thursday to Sunday morning for a month. Volunteers also filled out questionnaires every morning about whether they had been drinking the night before and whether they remembered the events of the evening.
The amount of reward for one person was up to $75, and there was also an opportunity to win one of eight $100 gift cards for participating in the experiment.
During the study, the researchers registered 486 episodes of alcohol consumption and 147 episodes of amnesia. More than two-thirds (69.3%) of students have experienced blackout at least once. To test the hypothesis, the scientists built multilevel logistic models and studied how certain indicators of transdermal alcohol concentration – the rate and duration of its growth, as well as the peak – are related to memory lapses.
“Our hypothesis was fully confirmed. We have identified three biomarkers of increasing alcohol intoxication – the rate of its achievement, duration and peak value – that predict the likelihood of blackout in college students who drink. The results support the idea that the way a person drinks is important for predicting the risk of alcoholic memory lapses,” the scientists said.
For example, on days when the participants’ blood alcohol intoxication levels increased rapidly, the risk of memory lapses increased by 2.69 times; when the peak alcohol concentration was the highest, by 2.93 times; and when the intoxication levels increased for a long time (in terms of the number of hours of drinking), by 4.16 times. If all three factors were present, only the duration of intoxication showed a significant correlation with Blackout.
“To reduce the risk of [memory lapses], it is important to consider how a person consumes alcohol, not just the amount. To predict alcoholic amnesia, the rate of intoxication, its peak values, and time are important. These predictors are important for prevention,” the scientists stated.
They also emphasized some of the study’s limitations: the small number of participants, with the majority being white (86.1%) and female (55.7%); the duration of the experiment was one month, which included St. Patrick’s Day (associated with drinking) and the Easter weekend (students tend to go home, where they drink less). In addition, the sensors could miss days with less intense alcohol consumption. Finally, some young people may not have realized that they did not remember certain moments during the morning survey, when they had not yet met their friends and exchanged impressions of the party.
