TUESDAY, April 15, 2003 (HealthDayNews) -- Young people who drink heavily and experience blackouts are more likely to have impaired memory skills than those who drink but don't have blackouts, a new study has found.
They also tend to reconstruct their fuzzy memories from their drinking bouts in positive way, so they have more positive expectations about future drinking than do drinkers who don't have blackouts.
When sober, the memory abilities of those drinkers who report blackouts and those who don't are the same. But when they drink, those who experience the blackouts have worse memory performance both during and immediately after they sober up than do their fellow drinkers who don't have blackouts, says Kim Fromme, an associate professor of psychology at the University of Texas at Austin.
"Alcohol clearly seems to impair these individuals' memory processes more than others," says Fromme, a corresponding author of the study, which appears in the April issue of Alcoholism: Clinical and Experimental Research.
Also of interest is that while it is known that heavy drinkers are likely to develop memory structures for alcohol effects that are biased toward positive incomes, this study suggests blackouts could accelerate this process, as those who had the blackouts reported strong positive expectations about future drinking.
"This is a really very interesting study," says William Fals-Stewart, a senior research scientist at State University of New York's Research Institute on Addictions in Buffalo.
"We often think about alcohol use as inducing memory problems, but this study suggests that memory problems facilitate alcohol use, which is a very different twist on how we think," he says.
In the study, Fromme and her colleagues recruited 55 men and 53 women whose average age was 22, and who reported that they indulged in binge drinking at least once a week, which meant five or more drinks on one occasion for men and four or more drinks for women. On average, the participants reported drinking 5.4 drinks per drinking occasion and drinking an average of nine times a month.
In addition, the study sample was broken down so half the participants had reported having blackouts in the past and half who did not.
For the study, the group was taken to a tavern-like setting for a half hour, where half of the group drank three vodka cocktails, and the other half drank three non-alcoholic drinks that had been doctored to simulate alcoholic drinks.
After a 15-minute absorption period, the young people were given Breathalyzer tests and then a series of tests to assess their memories. They then remained in a laboratory until those who had been drinking sobered up and then all were given additional memory tests.
Of the participants, those who drank alcohol and had reported prior blackouts when drinking had the worst responses to the memory assessments, which included tests such as seeing a list of 32 words and then, a half-hour later, having to match those remembered words to other words associated with the original words.
Although the study did not identify why some drinkers were more prone to blackouts than others, Fromme says those who did report the blackouts shared some traits not exhibited by those drinkers who did not have blackouts.
"Those who experienced fragmentary blackouts reported more frequent drinking, though not heavier drinking per occasion, and more positive beliefs about the effects of drinking alcohol," Fromme says.
Fromme says while this study can make no conclusions suggesting the blackouts could be markers for future alcohol problems, "they should not be ignored as possible indicators of alcohol-related problems."
"Health professionals should assess whether individual students experience fragmentary blackouts, and they should educate all students about the nature and potential negative consequences of fragmentary blackouts," Fromme says.
More information
The National Institute on Alcohol Abuse and Alcoholism offers some basic facts about alcoholism. A parent's guide to children's drinking can be found at the Nemours Foundation.
