A clear and in some ways surprising picture of alcoholism is emerging from a mammoth new nationwide survey sponsored by the National Institute on Alcohol Abuse and Alcoholism (NIAAA). Its findings show that alcoholism is primarily an affliction of youth and heighten suspicion that an underlying trait predisposes people to an unfortunate trifecta of alcoholism, substance abuse and mental disorders.
About 17.6 million people in the United States-about one in every 12 adults-abuse alcohol or are alcoholic. To understand how and why they drink, and in hopes of preventing this high-risk health behavior, NIAAA developed the National Epidemiologic Survey on Alcoholism and Related Conditions, or NESARC. It's the largest longitudinal study ever conducted in the United States on alcoholism and related conditions.
"Alcoholism is not what we thought it was," says psychologist Mark Goldman, PhD, NIAAA associate director and a University of South Florida researcher.
Scientists of all stripes are welcome to use NESARC's first wave of cross- sectional data, gathered in 2001 and 2002. Longitudinal data from the 2004-2005 data-collection phase will become available in 2007. Project directors also expect to conduct a larger survey.
NESARC is surveying not only alcohol-related behaviors but a host of mental disorders, many of which are tied to alcoholism, says survey director Bridget Grant, PhD, PhD, a double-doctorate psychologist and epidemiologist.
"We need to understand [alcoholism] in relation to all these other disorders if we're ever going to understand the cause," explains Grant, who heads NIAAA's Laboratory of Epidemiology and Biometry. Accordingly, says Goldman, NESARC offers essential baseline epidemiological data that characterizes the frequency and age distribution of alcoholism and mental illnesses.
Notably, the NESARC questionnaire measures symptoms of disorders such as major depression, antisocial personality and generalized anxiety disorder along a continuum, allowing for factor analyses. That, says Grant, makes the NESARC data "perfect for psychologists because that's the way they conceptualize the world-as along a continuum of mental health from normal to abnormal."
A sizeable sample
In the past, Goldman explains, studies on alcohol use and abuse were limited by their use of clinical populations, usually middle-aged alcoholics who finally hit bottom and sought treatment. But that self-selected group distorted the true picture.
By capturing a large representative sample-43,000 U.S. adults age 18 or older-NESARC has taken an accurate cross-sectional snapshot of alcohol abusers and will follow them over time. Survey designers enlisted 1,800 U.S. Census Bureau workers to personally interview participants. Researchers in 2004-2005 reinterviewed 87 percent of the original participants-an impressive follow-up rate, says Grant.
One of the survey's most notable finding so far is that problem drinking peaks at younger ages than researchers previously thought, with the highest prevalence among young adults ages 18 to 25. The results were published in Drug and Alcohol Dependence (Vol. 77, No. 2, pages 139-150). The numbers support Goldman's idea that alcohol dependence is a developmental disorder of the young, he says.
"Kids start drinking much earlier," he speculates, adding that other studies in younger age groups don't show the level of alcohol dependence NESARC found in young adults. Thus, he and other researchers are focusing more intently on children's risk factors, including having a sensation-seeking personality type and culturally imbued positive expectations about alcohol. NIAAA has launched an initiative on underage drinking and, last November, the U.S. Department of Health and Human Services launched an ad campaign urging parents to talk about alcohol to children as young as age 11.
NESARC also goes beyond basic epidemiology to study, for example, how people are treated for alcohol abuse, the demographic characteristics of people who get or don't get treatment, and barriers to treatment, especially among women, young adults and members of low-income and minority groups. Future NESARC data may bear on other critical questions, such as the impact alcoholism has on the workplace, binge drinking in college, and the line between safe and risky drinking.
Although alcohol is the survey's centerpiece, the data show its use and abuse are not independent of other problems. "Alcohol dependence is very highly co-morbid with drug use and mental disorders," says Grant. "We're trying to understand what the comorbidities mean."
For example, NESARC shows that not only do one out of 12 Americans abuse alcohol, but nearly one out of 10 adults appear to have a substance-use disorder (alcohol or drug or both). That overlap is consistent with some psychologists' concept of an "addictive personality."
Further analyses revealed that about one out of five Americans with substance abuse disorders had mood or anxiety disorders during that time. When the researchers reversed the question, they found that the same proportion of people with mood or anxiety disorders also had substance-use disorders.
Because people who sought treatment for mental disorders often had co-existing substance-use disorders and vice versa, NIAAA Director Ting-Kai Li, MD, said in an early report that to ensure comprehensive treatment, professionals should assess for and treat both substance-use and mental disorders at the same time. Untreated problems can lead to substance-use relapse and other bad outcomes.
For prevention, researchers can use new statistical techniques such as categorical or continuous latent trait modeling to determine whether NESARC data are consistent with the emerging "latent trait" model, in which researchers theorize that single stable factor underlies a common predisposition to poor mental health and substance abuse. Scientists might finally pin down risk factors for substance abuse and the odds of developing mental or physical disorders relative to that abuse, which would help clinicians advise patients (and health promotion experts tell the general public) how heavy drinking might put them at higher risk for, for example, liver disease or major depression.
To promote research using NESARC data, NIAAA has sent fliers about the database to every department of psychology, psychiatry and epidemiology in the United States. Grant, who reviews many of the resulting papers, says that many doctoral students are writing dissertations on the data.
The NESARC Web site includes the data itself (scrubbed clean of any identifiers), data notes, a code book that covers every variable and its frequency, an overview of methodology and the entire questionnaire. A data reference manual will be posted this spring. The data sets are formatted so they can be analyzed by popular statistical software such as SAS and SPSS and accompanying programs that adjust for the complex design features of the NESARC.
"This survey is a good example of the kind of infrastructure that is available for psychologists to use," says Steven Breckler, PhD, executive director of APA's Science Directorate. "APA would like to help researchers to understand the enormous potential of these large databases in the public domain, and to help them understand how to use them for original scholarship and publication."
NESARC can clear a path to multidisciplinary research as well, says Goldman. Its large data sample could help experts to define possible at-risk phenotypes and behavioral expressions of underlying genotypes-information that could ultimately lead to treatments of underlying vulnerabilities to alcohol abuse, substance abuse and mental disorders. To share in these exciting discoveries, Goldman urges psychologists to cross disciplinary lines and collaborate on what he calls "the next generation of progress."Rachel Adelson is a writer in Raleigh, N.C.
For more about NESARC findings, visit the NIAAA Web site at http://www.niaaa.nih.gov/. The survey data and supplemental materials can be downloaded from http://www.niaaa.nih.gov/NewsEvents/NewsReleases/Comorbidity.htm.
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