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		October 01, 2006 
		 
	
                    
                    
	
		
		
                        
                        Estimated 
		Prevalence of Compulsive Buying Behavior in the United States 
		
		 
	
	Lorrin M. Koran; Ronald J. Faber; Elias Aboujaoude; Michael D. Large; Richard T. Serpe 
		
		Am J Psychiatry 
		2006;163:1806-1812. 
		
                     
	
                    
                   
                    
                    
                    
                    
	
	
                    
                    
                     
                    
                    
				Abstract 
				 
				 
		Objective: Compulsive buying (uncontrolled urges to buy, with resulting significant adverse consequences) has been estimated to affect from 1.8% to 16% of the adult U.S. population. To the authors’ knowledge, no study has used a large general population sample to estimate its prevalence. Method: The authors conducted a random sample, national household telephone survey in the spring and summer of 2004 and interviewed 2,513 adults. The interviews addressed buying attitudes and behaviors, their consequences, and the respondents’ financial and demographic data. The authors used a clinically validated screening instrument, the Compulsive Buying Scale, to classify respondents as either compulsive buyers or not. Results: The rate of response was 56.3%, which compares favorably with rates in federal national health surveys. The cooperation rate was 97.6%. Respondents included a higher percentage of women and people ages 55 and older than the U.S. adult population. The estimated point prevalence of compulsive buying among respondents was 5.8% (by gender: 6.0% for women, 5.5% for men). The gender-adjusted prevalence rate was 5.8%. Compared with other respondents, compulsive buyers were younger, and a greater proportion reported incomes under $50,000. They exhibited more maladaptive (patterns of thinking and behavior that cause and maintain emotional problems. A maladaptive thinking pattern sometimes can be accompanied by "irrational beliefs," which are beliefs that are held even though they are not true) responses on most consumer behavior measures and were more than four times less likely to pay off credit card balances in full. Conclusions: A study using clinically valid interviews is needed to evaluate these results. The emotional and functional toll of compulsive buying and the frequency of comorbid psychiatric disorders (co-occurrence of one or more diseases or disorders in an individual) suggests that studies of treatments and social interventions are warranted. -------------------- Buying usually serves utilitarian/practical needs. For some adults, shopping is also a leisure activity (1), a means of managing emotions (2), or a way to establish and express self-identity (3). For others, the inability to control buying urges brings significant adverse consequences (4, 5). Uncontrolled problematic buying behavior has been referred to as uncontrolled buying (4), compulsive buying (6), compulsive shopping (7), addictive buying (8), excessive buying (9), and "spendaholism" (10). Although compulsive buying is not specifically described in DSM-IV, diagnostic criteria have been proposed. These include being frequently preoccupied with buying or subject to irresistible, intrusive, and/or senseless impulses to buy; frequently buying unneeded items or more than can be afforded; shopping for periods longer than intended; and experiencing adverse consequences, such as marked distress, impaired social or occupational functioning, and/or financial problems (5). The proposed diagnostic criteria are consistent with the reports of individuals who acknowledge problematic and uncontrolled buying behaviors (5, 6, 1113). The adverse consequences include guilt or remorse, excessive debt, bankruptcy, family conflict, divorce, illegal activities, such as writing bad checks and embezzlement, and even suicide attempts (6, 12, 14, 15). Estimates of the prevalence of compulsive buying in the adult U.S. population range from 1.8% (16) to 16% (17). However, no study, to our knowledge, has used a large general population sample to estimate prevalence. A more accurate prevalence estimate would help indicate the disorder’s impact on the public’s mental health. If the prevalence is substantial, interest in finding treatments will intensify. In addition, establishing a baseline prevalence would help elucidate the contributions to compulsive buying of differing or changing social conditions versus biological factors. Some authors, for example, have asserted that compulsive buying results from the conditions of modern life, including the easy availability of credit cards; increased and more effective advertising; the ease of shopping in malls, through TV, and the Internet; the dilution of family structure; and a breakdown in the sense of community (2, 1821). To establish a more accurate prevalence estimate, we conducted a nationwide random telephone survey using a validated screening instrument embedded in a structured interview. MethodData and Sampling
						The data were generated in the spring 
						and summer of 2004 from our national household telephone 
						survey, which interviewed 2,513 adults ages 18 and 
						older. The survey addressed shopping and buying 
						attitudes and behaviors and their consequences and 
						respondents’ financial and demographic data. The 
						interviews were conducted from the Social and Behavioral 
						Research Institute, California State University, San 
						Marcos, by interviewers with an average of 14 months of 
						experience in health-related telephone surveys and 
						specific training for this project. The Social and 
						Behavioral Research Institute conducts health surveys 
						for the federal Health and Human Services Agency and the 
						Centers for Disease Control and Prevention, numerous 
						health agencies, and academic researchers. The 
						interviewers used a computer-assisted telephone 
						interviewing system that guarded against errors of 
						omission and presentation. As an additional quality 
						control measure, the first author monitored pilot 
						interviews and provided feedback. During the 
						data-collection phase, supervisors monitored performance 
						during random interviews. To obtain informed consent, 
						interviewers identified themselves, the survey 
						organization, the study sponsor and survey topic, and 
						stated that the interview was voluntary, anonymous, 
						included no incentive, was terminable by the respondent 
						at any time, and might be monitored by a supervisor. The 
						interview was conducted with the first person ages 18 or 
						older answering the telephone. Interviews averaged 11.3 
						minutes. 
				
						The sample was obtained through 
						random-digit-dial telephone calls within the continental 
						U.S., stratified by state. All listed and unlisted 
						residential telephone numbers had an equal chance of 
						inclusion. Cell phone numbers were not included. This 
						household sampling method oversamples women and 
						undersamples younger individuals and some minorities. To 
						ensure that busy individuals were represented, telephone 
						numbers were called until finalized or 15 call attempts 
						had been made. A respondent was defined as a person who 
						completed a full or partial interview. A status of 
						"unknown study eligibility" could arise, for example, 
						from persistent busy signals or repeated answers by a 
						telephone answering device. The proportion of those with 
						unknown eligibility who were then assumed eligible was 
						set as equal to the proportion of known eligible persons 
						among people actually reached. Additional response rate 
						information accompanies the online version of this 
						article. 
				Measurement Scales
						To estimate the prevalence of 
						compulsive buying, we used the Compulsive Buying Scale
						
						(16) (available from the first author). The seven 
						scale items reflect a need to spend money (items 1 and 
						6), awareness that spending behavior is aberrant (item 
						2), loss of control (items 3 and 4), buying things to 
						improve mood (item 5), and probable financial problems 
						(item 7). 
				
						An individual’s Compulsive Buying 
						Scale score was generated from the responses to these 
						seven items through a formula. Individuals whose 
						Compulsive Buying Scale score was ≤1.34 are classified 
						as "compulsive buyers". This cutoff score (—1.34) was 2 
						standard deviations below the general population mean in 
						the original study and produced a prevalence estimate of 
						8.1%
						
						(16). Further data in support of these score 
						thresholds are presented in a supplement that 
						accompanies the online version of this article. For 
						comparison purposes, we also examined in separate 
						analyses individuals with scores 3 standard deviations 
						below the general population mean in the original study. 
				
						Lacking clinical interviews to 
						validate that compulsive buyers suffer from a clinically 
						significant disorder, we investigated one possible 
						measure of "severity" by conducting a post hoc analysis 
						of three preplanned questions that suggest loss of 
						control over buying: how often the individual 1) "just 
						wanted to buy things and did not care what you bought," 
						2) "bought something and when you got home were not sure 
						why you bought it," and 3) "went on a buying binge and 
						could not stop." The three questions had an internal 
						consistency Cronbach alpha of 0.59. We compared the 
						proportions of compulsive buyers and other respondents 
						who engaged in these behaviors "often" or "almost 
						always" and calculated the mean of the three items’ 
						summed scores (1 for "never" to 5 for "almost always"). 
						In addition, we compared the shopping and buying 
						attitudes and behaviors of the compulsive buyers and 
						other respondents using five other questions not 
						included in the Compulsive Buying Scale. 
				Data Analysis
						The analyses included  
				1) descriptive and comparison statistics for the sample’s demographics, 2) the prevalence of compulsive buying, 3) cross-tabulation and t test comparisons of those classified as compulsive buyers versus the remaining respondents in terms of demographics and shopping and buying attitudes and behaviors, and 4) logistic regression analysis to investigate the independent contribution of demographic and other variables to prevalence rates in subgroups. The significance level was set at p≤0.05, two-tailed, for comparisons of demographic variables and p≤0.05, one-tailed, for shopping or buying attitudes and behaviors, with compulsive buyers hypothesized to exhibit more maladaptive responses. For each analysis, cases were dropped list-wise when data were missing. Although missing data were minimal, missing cases resulted in some variation in the number of cases used in different analyses. 
						Compared with the U.S. adult 
						population, the respondents included a substantially 
						higher percentage of women and, to a lesser extent, a 
						higher percentage of people ages 55 and older (Table 
						1). A little over one-half (56.7%) of the 
						respondents were married compared to 52.5% in the U.S. 
						population (χ 2=17.33, df=1, p<0.001). The 
						respondents’ racial distribution closely resembled that 
						of the U.S. population but included a smaller proportion 
						of Hispanic individuals. Because the study sampling 
						method was stratified by state, the respondents were 
						representative of the U.S. population with regard to 
						distribution by state. 
				
						The Compulsive Buying Scale scoring 
						algorithm with a criterion score of ≤1.34 for 
						"compulsive buyers" (i.e., scores ≤2 standard deviations 
						below the mean) gave an estimated point prevalence of 
						compulsive buying of 5.8% and, by gender, a point 
						prevalence for women of 6.0% (90 of 1,501) and one for 
						men of 5.5% (44 of 800). Adjustment of the overall 
						prevalence figure to the gender distribution of the U.S. 
						adult population, i.e., multiplying the gender-specific 
						prevalence figures by the U.S. population gender 
						proportions and summing the results, also gave a point 
						prevalence rate of 5.8%. Using a Compulsive Buying Scale 
						score criterion of 3 standard deviations below the mean 
						for "compulsive buyer" produced an estimated prevalence 
						rate of 1.4% (33 of 2,301). Again, the estimated 
						prevalence was similar for women (1.5%, 23 of 1,501) and 
						men (1.3%, 10 of 800). 
				
						Compulsive buyers had a significantly 
						lower mean age (mean=39.7 years, SD=15.7) than other 
						respondents (mean=48.7 years, SD=16.5) (t=6.04, df=2234, 
						p<0.001). The two groups did not differ in the mean 
						number of people per household (mean=3.04, SD=1.80, 
						versus mean=2.83, SD=1.48). 
				
						Multiple logistic regression 
						analysis, including income group, gender, age, marital 
						status, and race/ethnicity as predictors of compulsive 
						buying status indicated that only income group (Wald χ
						2=5.79, df=1, p<0.02) and age (Wald χ 2=11.81, 
						df=1, p=0.001) were significant.  
				
						The income distribution of compulsive 
						buyers was shifted significantly toward those with a 
						lower income compared with those of other respondents. A 
						greater proportion of compulsive buyers reported incomes 
						under $50,000 (54.7% versus 39.3%) (χ 2=10.79, 
						df=1, p=0.001). 
				
						The demographic characteristics of 
						those with Compulsive Buying Scale scores 3 standard 
						deviations beyond the normal mean (N=33), including 
						gender distribution and mean number of people per 
						household, closely resembled those of the remaining 
						compulsive buyers (N=101) with scores 2 standard 
						deviations beyond the normal mean. 
				
						Compulsive buyers did not have more 
						credit cards than other respondents, but more of their 
						cards were within $500 and $100 of the credit limit (Table 
						2). The compulsive buyers were more than four times 
						as likely as other respondents to "very often" or 
						"often" make the minimum payment on credit card balances 
						(Table 
						2). This greater propensity was present within each 
						of the eight pre planned income groups between under 
						$10,00 and under $150,000; the number of compulsive 
						buyers with incomes of ≥$150,000 was only four, 
						precluding meaningful description. 
				
						Compulsive buyers did not differ 
						significantly from other respondents in mean total 
						credit card balances, but the Compulsive Buying Scale 
						compulsive buyers’ lower income level was a confounding 
						factor. To control for income, we performed a post hoc 
						analysis of total credit card debt. We collapsed the 
						respondents as equally as possible into four income 
						subgroups that became the following: <$25,000 (N=335), 
						$25,000 to <$50,000 (N=403), $50,000 to <$75,000 
						(N=522), and ≥$75,000 (N=614). The post hoc comparisons 
						indicated a non significant tendency for compulsive 
						buyers to have higher credit card balances in each 
						category, with the largest differences occurring in the 
						<$25,000 ($2,660 versus $1,530) and the ≥$75,000 
						categories ($6,130 versus $3,850). The large variances 
						within each category, however, limited the power of the 
						analysis. 
				
						As hypothesized, the compulsive 
						buyers exhibited more maladaptive shopping and buying 
						attitudes and behaviors than the other respondents, 
						thus, supporting the validity of the dichotomy. 
						Compulsive buyers engaged in "problem shopping" more 
						often and for longer periods (Table 
						2). They took greater pleasure in shopping and 
						buying, more often make senseless and impulsive 
						purchases, more often feel depressed after shopping, and 
						more often experiencing uncontrollable buying binges (Table 
						3). The compulsive buyers also exhibited 
						substantially higher scores on the post hoc "severity" 
						measure (mean=2.73, SD=0.83, versus mean=1.67, SD=0.54), 
						but given its post hoc nature, no statistical testing 
						was performed. 
				
						With regard to the variables 
						displayed in
						
						Table 1,
						
						Table 2, and
						
						Table 3, those with Compulsive Buying Scale scores 3 
						standard deviations beyond the normal mean differed from 
						the remaining compulsive buyers with scores 2 standard 
						deviations beyond the normal mean only in that a smaller 
						proportion were white (42.4% versus 65.4%; χ 2=5.1, 
						df=1, p<0.03) and a greater proportion went on buying 
						binges and could not stop "almost always" or "often" (Table 
						3, question 27) (30.4% versus 13.8%) (χ2=9.78, 
						df=4, p<0.05). 
				
						This large random sample nationwide 
						telephone survey that used a validated screening 
						instrument suggests that compulsive buying is a common 
						problem among U.S. adults, 
						affecting more than one in 20 
						adults. Previous research has documented significant 
						suffering and impairment associated with this behavior. 
						The gender-adjusted point prevalence (5.8%) produced by 
						the recommended Compulsive Buying Scale cut-off score was 
						considerably higher than those for major depression 
						(about 1.5%
						
						[22]) and generalized anxiety disorder (1.5%—3.0%
						
						[23]), disorders that command substantial clinical 
						and research attention. 
						A self-help book has apparently 
						been apt in referring to compulsive buying as "the 
						smiled-upon addiction"
						
						(24). An extremely conservative 3 standard deviation 
						Compulsive Buying Scale cut-off point below the 
						respondents’ mean produced a point prevalence estimate 
						(1.4%) similar to those for major depression and 
						generalized anxiety disorder. For both the 2 standard 
						deviation and 3 standard deviation compulsive buyers, 
						the gender-specific prevalence rates were quite similar, 
						as are the identified individuals’ demographic and 
						clinical characteristics. 
				
						The validity of the larger prevalence 
						estimate is supported first by the finding, albeit in 
						small samples, that subjects meeting the 2 standard 
						deviation Compulsive Buying Scale criterion almost 
						always meet the suggested clinical diagnostic criteria
						
						(12,
						
						25) and vice versa
						
						(26). The estimate’s validity is further supported 
						by the observation that the present study’s compulsive 
						buyers exhibited more maladaptive shopping/buying 
						attitudes and behaviors and more adverse financial 
						consequences than the remaining respondents. Finally, 
						the developers of the Compulsive Buying Scale pointed 
						out that using a criterion score of 3 standard 
						deviations below the respondents’ mean "would mean a 
						high likelihood of excluding many people who truly are 
						compulsive buyers." 
				
						Still, without a structured clinical 
						interview such as the 
						Minnesota Impulsive Disorders 
						Interview
						
						(12) administered by a mental health professional, 
						we cannot be certain that any of the compulsive buyers 
						suffered from the clinical condition termed "compulsive 
						buying" or merit clinical attention. As in any telephone 
						survey, some respondents may have exaggerated responses 
						(e.g., income) or been reluctant to admit unpleasant 
						truths (e.g., credit card debt). The prevalence figure 
						derived from the Compulsive Buying Scale may be too 
						high, if, for example, there is a response bias toward 
						considering shopping and buying as prestigious and thus 
						to overstate one’s involvement. The figure could be too 
						high if those meeting the Compulsive Buying Scale 
						criterion do not meet the suggested clinical diagnostic 
						criteria
						
						(5). The Compulsive Buying Scale does not include 
						items, for example, that reflect preoccupation with 
						buying or buying unneeded items, and the scale’s adverse 
						consequences item is limited to writing uncovered 
						checks. Furthermore, a small proportion of those meeting 
						the Compulsive Buying Scale criterion may have done so 
						because they were hypomanic or manic. Finally, the 
						prevalence figure may be accurate but include many cases 
						with minimal "severity." Our post hoc severity indices, 
						however, argue against this. Compulsive buyers were 
						significantly more likely to answer in the maladaptive 
						range on each of the index questions (numbers 24, 26, 
						and 27). They also exhibited a substantially higher mean 
						score on the post hoc severity measure, although this 
						measure does not capture all potential aspects of 
						"severity." 
				
						By contrast, the Compulsive Buying 
						Scale prevalence figure may be too low, if, for example, 
						respondents were embarrassed to admit how much time and 
						money they devoted to shopping and buying and the 
						negative consequences. The figure could be too low 
						because we were less successful contacting groups that 
						appear to have a higher prevalence, i.e., younger 
						individuals who more frequently use cell phones and 
						individuals of a lower socioeconomic status who are less 
						likely to have a telephone. It could be too low if 
						compulsive buyers were less likely to be home to answer 
						their telephones (because they were out shopping). 
				
						To determine the true prevalence of 
						clinically significant compulsive buying will require 
						administering a structured, validated, diagnostic 
						interview to a large and representative sample of the 
						population. Comparing the diagnostic results of these 
						interviews to the interviewed individuals’ Compulsive 
						Buying Scale scores would provide an indication of the 
						false positive and false negative rates of potential 
						cut-off points, including the cutoff score (—1.34) that 
						we used as our primary criterion. Because a screening 
						instrument’s false positive and false negative rates are 
						specific to the sample examined
						
						(27), we could not use the rates observed in the 
						original Compulsive Buying Scale study
						
						(16) or in a subsequent clinical study
						
						(26) to correct the prevalence figure we observed. 
				
						Our estimate is constrained by our 
						rate of response: 56.3%. Although substantial, it does 
						not guarantee that our sample is representative of the 
						U.S. adult population with regard to shopping and buying 
						attitudes and behaviors. This response rate compares 
						favorably, however, with those obtained in nationwide 
						health surveys. Our estimate is also constrained by 
						differences between the study sample and the U.S. adult 
						population. First, the sample contained a smaller 
						proportion of younger individuals and somewhat fewer 
						Hispanic individuals. Logistic regression demonstrated, 
						however, that after we controlled for income and age, 
						race/ethnicity did not contribute to differences in 
						prevalence rates. Third, the sample contained a higher 
						proportion of women. To compensate for this, we provided 
						a gender-adjusted prevalence estimate, but the result 
						was unchanged. 
				
						If we accept this study’s point 
						prevalence estimate as approximately accurate, certain 
						additional conclusions follow. 
						 
				
 
 
 
 
 
							Received 
							Feb. 16, 2005; revisions received June 22 and Sept. 
							7, 2005; accepted Sept. 27, 2005. From the 
							Department of Psychiatry and Behavioral Sciences, 
							Stanford University School of Medicine; the 
							Department of Journalism and Mass Communication, 
							University of Minnesota, Minneapolis; the Department 
							of Sociology and the Social and Behavioral Research 
							Institute, California State University, San Marcos; 
							and the Department of Sociology, Kent State 
							University, Kent, Ohio. Address correspondence and 
							reprint requests to Dr. Koran, OCD Clinic, Rm. 2363, 
							401 Quarry Rd., Stanford, CA 94305; lkoran@stanford.edu 
							(e-mail). Dr. Koran reports being on the speaker’s 
							bureau for Forest Pharmaceuticals and receiving 
							grants from Ortho-McNeil, Eli Lilly and Company, 
							Forest Pharmaceuticals, Somaxon, and Jazz. Dr. 
							Aboujaoude reports being on the speaker’s bureau for 
							Forest Pharmaceuticals during the time the study was 
							conducted. Drs. Faber, Large, and Serpe report no 
							competing interests.Supported by an unrestricted 
							educational grant from Forest Pharmaceuticals, Inc. 
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