New research from Washington University School of Medicine in St. Louis has found substantial reductions in binge drinking since the national drinking age was set at 21 two decades ago, with one exception: college students. The rates of binge drinking in male collegians remain unchanged, but the rates in female collegians have increased dramatically.
Reporting in the July issue of the Journal of the American Academy of Child and Adolescent Psychiatry, the researchers say although policy initiatives aimed at lowering rates of underage drinking generally have been successful and that binge drinking is down among young people overall, it remains a problem on college campuses.
The researchers, led by Richard A. Grucza, Ph.D., assistant professor of psychiatry, analyzed data gathered between 1979 and 2006 by the National Survey on Drug Use and Health. The information comes from more than 500,000 subjects, and the researchers divided them into groups, according to age, sex, ethnicity and student status.
"We found that overall, binge drinking is less common than it once was," Grucza says. "Young men account for the majority of binge drinkers, and their rates have dropped substantially since 1979. However, at the same time, the 'gender gap' between male and female drinkers has been closing. In this study, we found that women are drinking more, and their rates of binge drinking have risen over the last 30 years."
Binge drinking is defined as having five or more drinks on a given occasion. In 2006, the last year for which the data were analyzed, more than half of college-age males, and almost 40 percent of college-age females reported binge drinking. But the researchers found reductions in binge drinking, especially among boys and young men 20 and younger. In males ages 15 to 17, binge-drinking rates declined nearly 50 percent between 1979 and 2006. During the same period, rates declined more than 20 percent in males aged 18 to 20 and 10 percent in males aged 21 to 23.
In women ages 15 to 20 on the other hand, binge drinking was statistically unchanged since 1979. For women 21 to 23, binge drinking rose by about 40 percent.
Meanwhile, binge drinking decreased among men who are African-American, Hispanic or belong to other minority groups. But it increased among minority women.
The biggest surprises involved differences between college students and men and women of the same age not enrolled in college. Binge drinking declined in young men, unless they were in college. It was up slightly in young women, but significantly higher in college women.
Among 18- to 20-year-old non-college men, binge drinking declined by more than 30% over the study period, whereas it was statistically unchanged among the men in college. For men ages 21 to 23, rates of binge drinking declined just more than 10 percent but remained virtually the same in those of the same age who attended college. In women ages 21 to 23, binge drinking increased about 20 percent among non-students, but the increase was more than 40 percent among women in college.
"The tendency for binge drinking to decline in society has not permeated our college campuses," says Grucza. "Some researchers have speculated that because colleges are made up of young, mostly unmarried people — with no parental control and no spouse to check in with — they may be more likely to drink to excess than people of the same age who live with their parents or have a spouse. Plus, most have easy access to alcohol because at least some of their peers are 21 or older."
But with the minimum age at 21, Grucza says it's less likely that high school students have peers of legal drinking age. Since the minimum national drinking age of 21 was signed into law in 1984, it has become more difficult for younger teenagers to get alcohol and apparently has contributed to lower binge drinking rates among those under 18.
He says stable rates of binge drinking among college students and increases in binge drinking among women have offset some of that improvement and developing a better understanding of the reasons for those demographic trends, rather than lowering the drinking age, will assist future efforts to prevent binge drinking.
"Many proponents of lowering the drinking age argue that the higher drinking age has led to more binge drinking," Grucza says. "There is no evidence to support that. Our study and other studies show the higher age has decreased the amount of alcohol consumed by young people, the number of binge-drinking episodes overall, the number of fatal car crashes and other adverse alcohol-related outcomes. There may be good, philosophical arguments about why the drinking age should be lower than 21, but our study demonstrates the higher minimum drinking age has been good for public health."
Grucza RA, Norbert KE, Bierut LJ. Binge drinking among youths and young adults in the United States: 1979-2006. Journal of the American Academy of Child and Adolescent Psychiatry, 48: July, 2009. pp 692-702.
This study was supported by grants from the National Institutes of Health.
Washington University School of Medicine's 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's Hospitals. The School of Medicine is one of the leading medical research, teaching, and patient care institutions in the nation, currently ranked third in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's Hospitals, the School of Medicine is linked to BJC HealthCare.