From the way that Americans ratchet up credit card debt, one could easily get the impression that all Americans are compulsive buyers. But is that really the case? Probably not. Nonetheless, there seem to be quite a few of them, a new study suggests.

The investigation was headed by Lorrin Koran, M.D., an emeritus professor of clinical psychiatry at Stanford University. Results appeared in the October American Journal of Psychiatry.

Past surveys have suggested that the prevalence of compulsive buying in the United States is anywhere from 2 percent to 16 percent. However, none of these inquiries used a large general population sample to estimate prevalence. So Koran and his colleagues decided to do so. They conducted phone interviews with a random selection of some 2,500 Americans from the general population, using the Compulsive Buying Scale as their yardstick.

The scale had been designed by one member of their group, Ronald Faber, Ph.D., and by another researcher, T.C. O'Guinn, Ph.D., in 1992 to assess people's urge to spend money, whether buying improves their mood, whether they incur debt from spending, and so forth. Currently Faber is a professor of mass communication at the University of Minnesota, and O'Guinn is a professor of marketing at the University of Wisconsin.

Koran and his team also decided that any respondent whose score on the scale fell two standard deviations below the average would be designated a compulsive shopper. The reason, Koran explained to Psychiatric News, is that "this cut point has proven its validity in clinical studies.. .where individuals meeting the two standard-deviation criterion almost always meet the clinical diagnostic criteria that have been suggested for compulsive buying."

Using these criteria for a compulsive buyer, Koran and his team arrived at a prevalence rate of 6 percent.

Moreover, those they identified as compulsive buyers were younger, more likely to have incomes under $50,000, and four times less likely to pay off credit card balances in full compared with noncompulsive buyers. In contrast, there were about as many male as female compulsive buyers.

Donald Black, M.D., a professor of psychiatry at the University of Iowa who has studied compulsive buying, found this latter finding especially intriguing because it runs counter to some previous ones.

"In my experience," he told Psychiatric News," women readily acknowledge that they enjoy shopping, whereas men are more likely to report that they `collect,' which may indicate that previous studies simply did a poor job of identifying men with compulsive buying. Unfortunately, the study did not delve into the gender-based differences in buying preferences, and more work needs to be done to explore this."

More work also needs to be done to determine whether compulsive buying is a psychiatric disorder, Koran and his team said in their report. Structured clinical interviews administered by a mental health professional would be necessary to do that, they wrote.

And if compulsive buying were to become a diagnosable mental disorder, there would be several advantages to it, Eric Hollander, M.D., chair of psychiatry at Mount Sinai School of Medicine, and Andrea Allen, Ph.D., an assistant professor of psychiatry there, pointed out in an accompanying editorial.

"It might facilitate routine screening for the condition by mental health professionals, and perhaps even inclusion of the disorder in national prevalence surveys, which would help define the true prevalence of the disorder," they wrote. "It might also lead to the study of vulnerability factors for the development of the disorder, better characterization of brain-based circuits, and the development of effective psychosocial and medication treatments."

In fact, when Psychiatric News asked Hollander whether he thinks compulsive buying should be included in DSM-V, he replied," Yes. It meets all the usual patterns and criteria for an impulse-control disorder and is associated with distress and functional impairment." Moreover, compulsive shopping is related to depression and bipolar disorder, a French investigation showed (Psychiatric News, July 19, 2002).

However, there would be one drawback to "medicalizing" compulsive shopping, Koran and his group cautioned. Focusing on affected individuals might obscure possible social contributions to the problem, such as easy credit, predatory interest rates, and inadequate money management training for young people.

The study was funded by an unrestricted educational grant from Forest Pharmaceuticals.

"Estimate Prevalence of Compulsive Buying Behavior in the United States" is posted at<http://ajp.psychiatryonline.org/cgi/content/full/163/10/1806>.▪