James Hudson & Ron
Kessler talks with ScienceWatch.com and answer a
few questions about this month's New Hot Paper in the field
of Neuroscience & Behavior.
Article Title: The prevalence and correlates of
eating disorders in the national comorbidity survey
replication
Authors:
Hudson,
JI;Hiripi, E;Pope,
HG;Kessler,
RC
Journal: BIOL PSYCHIAT
Volume: 61
Issue: 3
Page: 348-358
Year: FEB 1 2007
* McLean Hosp, Biol Psychiat Lab, 115 Mill St, Belmont, MA
02478 USA.
* McLean Hosp, Biol Psychiat Lab, Belmont, MA 02478
USA.
* Harvard Univ, Sch Med, Dept Psychiat, Belmont, MA 02178
USA.
(addresses have been truncated)
Why do you think your paper is highly
cited?
The paper reports the first nationally representative population-based data
on the prevalence and correlates of eating disorders in the United States.
The data come from the National Comorbidity Survey Replication (NCS-R), a
nationally representative psychiatric epidemiological survey of the US
household population that gathered data on the prevalence and correlates
of a wide range of mental disorders.
Because the data in our paper are unique, many subsequently published
papers covering a variety of aspects of eating disorders and disturbed
eating have cited our paper as an authoritative source for estimates of the
prevalence and demographic features of eating disorders.
In addition, our paper reports the first population-based epidemiological
data on the prevalence and correlates of binge eating disorder. Binge
eating disorder is characterized by recurrent eating binges during which an
individual eats an unusually large amount of food in a short period of
time, associated with a feeling of loss of control over the eating, but
without the "purging behaviors," such as self-induced vomiting or laxative
abuse, seen in bulimia nervosa.
We showed both that binge eating disorder is relatively common in
comparison with bulimia nervosa and also that binge eating
disorder is associated with very similar chronicity and impairment as
bulimia nervosa. The latter finding is of special importance in
light of the fact that the current diagnostic system used in the US, the
Fourth Edition of the American Psychiatric Association's Diagnostic and
Statistical Manual of Mental Disorders (DSM-IV), does not include binge
eating disorder as a definite disorder but rather as a condition of
possible interest that might at some future date be upgraded to be
considered a definite disorder.
As the DSM system is currently in the process of being revised, a great
deal has been written recently about various proposed changes in the next
edition. Many of the papers that have cited our paper focus on binge eating
disorder and cite our evidence of chronicity, substantial impairment, high
levels of psychiatric comorbidity, and risk for
obesity as evidence that
binge eating disorder should be upgraded to a definite disorder in the next
edition of the DSM system.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
As noted above, the paper reports new findings in two principal areas.
First, it provides the first nationally representative data on the
prevalence and correlates of eating disorders in the United States. For
anorexia nervosa and bulimia nervosa, these data largely
provide confirmation of the results of previous smaller or less
representative studies. Second, the study provides the first general
population data on binge eating disorder, including data on prevalence and
correlates.
We found that binge eating disorder is more common than anorexia
nervosa and bulimia nervosa combined (affecting 3.5% of women
and 2.0% of men over the course of their lifetime), is often a chronic
condition, is associated with the presence of other mental disorders, is
associated with obesity (particularly severe obesity), and has increased in
prevalence in recent cohorts. These findings suggest that binge eating
disorder contributes to the obesity epidemic and that it represents a major
and underrecognized public health problem.
As noted above, binge eating disorder is currently classified as a
provisional entity (i.e. a "proposed diagnosis," rather than an "official"
diagnosis) in the DSM-IV, the official classification of mental disorders
in the United States. As work begins on the fifth edition (DSM-V), there is
much interest in the question of whether binge eating disorder merits
inclusion as an official diagnosis. The results of our paper provide
important new data on this issue, and weigh in favor of elevating binge
eating disorder to an official diagnosis.
Would you summarize the significance of your paper
in layman's terms?
Many people, both laymen and scientists, have questioned whether binge
eating disorder represents a genuine psychiatric disorder, or whether it
might be simply a particular pattern of eating that occurs from time to
time in people who are obese. In the past, lacking national epidemiologic
data, it has been difficult to answer this question. Our study now suggests
that binge eating disorder is a common, relatively stable condition that's
associated with both psychiatric morbidity and medical morbidity. These
findings weigh in favor of binge eating disorder being a genuine
psychiatric disorder rather than merely an idiosyncratic pattern of eating.
How did you become involved in this research, and
were there any problems along the way?
As noted above, this paper was prepared as part of the work of the National
Comorbidity Survey Replication (NCS-R), a nationally representative survey
of the prevalence and correlates of mental disorders in the US household
population. The NCS-R was carried out in 2001-3. The NCS-R is a replication
and expansion of the earlier National Comorbdity Survey (NCS), a national
survey that was carried out a decade before the NCS-R. Comparisons of
results in the NCS and NCS-R have been used to monitor trends in the
prevalence of mental disorders in the US and to study changes in patterns
of treatment for these disorders.
One of the expansions in the NCS-R was the inclusion of information about
eating disorders, which were not included in the earlier NCS. Once a
decision was made to include eating disorders in the NCS-R, the NCS-R
survey team, which is led by Ron Kessler, established collaboration with
James Hudson and Harrison Pope, who are experts in the study of eating
disorders, to work on this part of the NCS-R data. No major problems were
encountered once the decision was made to include an assessment of eating
disorders in the survey. Data collection and subsequent data analysis went
smoothly.
Where do you see your research leading in the
future?
Finding as we did that eating disorders are common and often chronic, it
will become important to expand investigation of the public health
implications of this disorder in future epidemiological surveys. To that
end, the NCS-R assessment of eating disorders has now been included in the
nationally representative surveys carried out in the
World Health Organization’s World Mental Health
Survey Initiative.
WMH surveys are being administered in 28 countries around the world. With
regard to binge eating disorder, a new long-term follow-up study has now
been initiated by Hudson and colleagues to examine the extent to which
binge eating disorder is a risk factor for obesity and cardiometabolic
disorders.
Do you foresee any social or political implications
for your research?
We expect that the results of this study will be considered in the
deliberations regarding whether to add binge eating disorder as an official
diagnosis in DSM-V. Inclusion of binge eating disorder would result in
greater coverage for treatment by insurance plans and thus would increase
access to treatment for individuals suffering from this condition.
More broadly, if binge eating disorder represents a cause of obesity
stemming from an underlying neuropsychiatric dysregulation, identification
and potential treatment of this dysregulation might reduce the risk of
obesity and other adverse psychological and physical consequences of binge
eating.
James I. Hudson, M.D., Sc.D.
Professor of Psychiatry
Harvard Medical School
Director, Biological Psychiatry Laboratory
Director, Psychiatric Epidemiology Research Program
McLean Hospital
Belmont, MA, USA
Ronald C. Kessler, Ph.D.
Professor of Health Care Policy
Harvard Medical School
Principal Investigator, National Comorbidity Survey
Boston, MA, USA