Who should define disease?BMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d2974 (Published 11 May 2011) Cite this as: BMJ 2011;342:d2974
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In BMJ's editorial of 11 June 2011 (1), Fiona Godlee asked the
question 'Who should define disease?' This question was answered by
international treaty in 1948, when the World Health Organization (WHO) was
founded as a specialized agency of the United Nations. As 'the world's
only truly multilateral health institution' (2), WHO has a unique
authority to initiate and promote global health standards and to secure
international cooperation and agreement on the definition of diseases.
Among the core functions of WHO described in its Constitution (3) are
responsibility for international definitions and nomenclatures of
diseases, causes of death and public health practices, and the
standardization of diagnostic procedures.
This includes the maintenance and revision of the International
Classification of Diseases (ICD), the global standard for health
information for assessment and monitoring of mortality, morbidity, and
other health parameters. One of WHO's earliest official actions was to
publish the ICD-6 (4) in 1949, the first to include a classification of
mental disorders. As a part of the treaty governing their membership,
WHO's 193 Member States have agreed to use the ICD as a basis for
reporting health information so that it is usable and comparable across
countries. The World Health Assembly--WHO's governing body, comprised of
the health ministers of all Member States--has directed WHO to revise the
ICD-10 (5), a process that is expected to lead to the completion of the
ICD-11 in 2014.
As Godlee pointed out, the classification of mental disorders is a
particularly sensitive example in terms of the definition and creation of
disease categories. The WHO Department of Mental Health and Substance
Abuse has lead responsibility for the development of the ICD-11 chapter on
mental and behavioural disorders, assisted by a globally representative,
multidisciplinary Advisory Group (6). WHO has implemented a systematic
process for evaluation and use of evidence for the development of the ICD-
11 classification of mental and behavioural disorders, including formative
and evaluative field testing. WHO believes that substantial changes to
existing mental disorders categories and definitions should be made
through a transparent, international, multidisciplinary, and multilingual
process that involves the direct participation of a broad range of
stakeholders and is as free as possible from conflicts of interest. As
Moynihan (7) argued, a truly multilateral process of disease definition
cannot be legitimately managed by a single professional organization
representing a single health discipline in a single country with a
substantial commercial investment in its products.
The governments of WHO Member States are primary stakeholders in this
process. Not only do they use the ICD for health data collection,
communication, and reporting, but the ICD provides a large part of the
framework that defines their obligations to provide free or subsidized
health care, social services, and disability benefits to their citizens,
in combination with health care and reimbursement policies and relevant
laws. People are only likely to have access appropriate mental health
services when the conditions that define eligibility and treatment
selection have their basis in a diagnostic system that is valid, usable,
and useful. Changes to the ICD involve the commitment of substantial
government resources to change record systems, health survey instruments,
administrative procedures, payment mechanisms, health policy, and
legislation related to diagnosis and eligibility, social and educational
services, and legal protections.
A second stakeholder group is health care professionals, who will be
expected to implement any change in disease definitions. The definition of
mental disorders has historically been dominated by psychiatry, but,
worldwide, a small percentage of individuals with mental disorders will
ever see a psychiatrist. The ICD must be usable and useful in those
settings in which people with mental disorders are mostly likely to come
into contact with the health care system, by the types of professionals
who provide services there. Other relevant groups include psychologists,
social workers, psychiatric nurses, primary care physicians, who are
represented on the Advisory Group, as well as lay health care workers who
deliver the majority of primary and mental health care in some developing
Users of mental health services and their family members are a third
direct stakeholder group. The user community in mental health has been
increasingly aligned with the disability rights movement, adopting the
motto of 'Nothing about us without us!', rejecting what they see as
medical paternalism, and demanding to be consulted about the decisions
that affect their lives. We are making a serious effort to provide
substantive opportunities for participation of user groups, rather than
symbolic or ritualistic gestures (8).
We are attending to geographic and linguistic diversity carefully in
creating mechanisms for participation in the ICD mental and behavioural
disorders revision at all levels, including the formation of expert
groups. All surveys, and field studies are being conducted in multiple
languages (9). This is in contrast to previous revision efforts, which
were dominated by individuals from wealthier, usually Anglophone,
countries who have been able to travel and participate in meetings
conducted in English. We are also addressing the influence of the
pharmaceutical industry and other commercial interests very seriously.
WHO's policy on declarations of interest has recently been further
clarified to require detailed examination of these issues prior to any
appointment to a role with an influence on the definition of mental
disorders, and provides explicit guidance on their recognition and
Conducting the revision of the classification of mental and
behavioural disorders within the overall context of ICD revision
facilitates coordination with classification of other disorders,
particularly neurological and other medical conditions that are frequently
comorbid with mental and behavioural disorders. The integration of mental
and behavioural disorders with all other diagnostic entities is an
important feature of ICD, facilitating the search for related mechanisms
of aetiology, pathophysiology, and comorbidity of disease processes and
providing a basis for parity of psychopathology with the rest of the
medical system for clinical, administrative, and financial functions in
Like Godlee and Moynihan, WHO is concerned about the proliferation of
mental and behavioural disorder diagnoses over time. Redundancy and
clinically unimportant distinctions in disease definitions may result from
the use of classification systems by professional societies as a vehicle
for marking professional turf, something that is much less likely in the
context of a global public health agency. Even so, issues of threshold are
extremely complex given that the pathophysiology underlying mental
disorders still cannot be assessed directly and that many symptoms of
psychopathology are clearly continuous with normal phenomena. There is
fierce scientific and social debate regarding the differentiation from
normality of several proposed disorders (e.g., complicated grief, mild
cognitive impairment, temper dysregulation). Appropriate use of the ICD
would discourage the reification of questionable disease entities,
particularly when these reflect specific behaviours, isolated symptoms, or
relational problems. The ICD contains specific provisions for identifying
clinically important phenomena that have a substantial influence on
treatment and management but are not in themselves disorders (i.e.,
chapters on Symptoms, signs, and abnormal clinical and laboratory findings
and Factors influencing health status and encounters with health
It does not follow automatically from the identification of a
phenomenon as an important area for research that it should be defined as
a disease. Evidence regarding validity and clinical importance should be a
basic requirement, and the public health justification for inclusion must
also be considered. Disease classifications have not proved to be the best
organizing framework for research on basic mechanisms (10), but the
usefulness of a classification for research should not be confused with
its validity for other purposes. Research and evidence evaluation for
disease definition should focus on their different purposes and target
users, incorporating a broader range of methodologies appropriate to the
evaluation of clinical utility and public health outcomes.
The argument for definition of new conditions is often implicitly
based on the goal of obtaining reimbursement to treat them, if not to
expand markets for pharmaceutical products. This has led to many of the
questionable diagnostic categories that are extant today. However, health
care financing is a separate issue from disease definition (8), with
reimbursement policy representing a third area, and it is not helpful to
the project of reducing global disease burden to conflate them. That is,
the inclusion of the condition in the classification manual does not
automatically mean that treatment should be provided or that the
government or private insurance should pay for it. Failure to separate
diagnosis from health policy contributes to over-treatment, but also to
the under-treatment of serious mental disorders and the misdirection of
mental health care resources.
WHO's role in disease definition is not exclusive. Government
organizations such as the NIH in the USA and NICE in the UK, national and
international professional organizations, disease societies, and consumer
organizations have a legitimate contribution. However, WHO's
constitutionally defined role as 'the directing and coordinating authority
on international health work' (3) provides WHO with a unique and
irreplaceable standing for setting standards for disease definition,
convening relevant parties and coordinating multilateral global action.
In a 'new deal' (6) on disease definition, WHO has a central role to play.
Geoffrey M. Reed, Tarun Dua, and Shekhar Saxena
World Health Organization
1. Godlee F. Who should define disease? BMJ 2011;342:d2974.
2. Horton R. Offline: evidence-based atrophy. The Lancet
3. World Health Organization. Basic documents, 46th edition. Geneva:
World Health Organization, 2007.
4. World Health Organization. International statistical
classification of diseases, injuries, and causes of death, 6th revision.
Geneva: World Health Organization, 1949.
5. World Health Organization. International statistical
classification of diseases and related health problem, 10th Revision.
Geneva: World Health Organization, 1992.
6. International Advisory Group for the Revision of ICD-10 Mental
and Behavioural Disorders. A conceptual framework for the revision of the
ICD-10 classification of mental and behavioural disorders. World
7. Moynihan R. A new deal on disease definition. BMJ 2011;342:d2548.
8. Reed GM. Towards ICD-11: creating a space for diverse
perspectives [Vers la CIM-11: cr?er un espace pour une diversit? de
perspectives]. Inf Psychiatr 2011;87:169-173.
9. Reed GM, Correia JM, Esparza P, Saxena S, Maj M. The WPA-WHO
global survey of psychiatrists' attitudes towards mental disorders
classification. World Psychiatry 2011;10:118-131.
10. Insel T, Cuthbert B, Garvey M, Heinssen R, Pine DS, Quinn K,
Sanislow C, Wang P. Research domain criteria (RDoC): toward a new
classification framework for research on mental disorders. Am J Psychiatry
11. World Health Organization. The world health report - Health
systems financing: the path to universal coverage. Geneva: World Health
Competing interests: No competing interests
Contemporary knowledge in medicine is very complex, and no human mind
can absorb it all as was possible in ancient times. Accordingly with the radical scientific, technological changes and the coming of new
paradigms, we can call the last century by several names, one of them being the century of medicine. Never before, in human history were there so many
discoveries related to medicine as there were in the 20th century.
Biophysics, Biochemistry, Immunology, Genetics, Pharmacology are
responsible for the appearance of new paradigms in the health sector.
Pathogenesis, independently from its causes, has several development
levels, from the molecular to the microscopic. Long before the
appearances observed by the naked eye, classic signs and symptoms of
disease, there are troubles at subatomic, atomic, molecular,
supramolecular, cellular, tissue levels. In each of them the body has its
own compensation mechanisms. When one of these procedures fails or is
deficient, pathological signs appear.
Disease must be defined taking into account the characteristics that it
has when the possibility of working against them exists to bring
the organism to a normal state. The majority of definitions, in health,
characterize disease in a state when is not possible to cure the patient.
Using those definitions physicians find changes in their patients when it
is only possible to do one or both of these two things: treat pharmacologically to
reduce the violence of disease and so ameliorate the clinical frame of it,
or surgically remove damaged parts of the body for solving the problem. In both cases they cannot heal or cure their patients.
Disease must be defined by its classic characteristics at tissue and
subcellular level. They can be detected by laboratory methods. At this
level, disease is at a reversible state. In this phase, a highly qualified
physician must be capable of taking correct actions for diagnosing and
reversing the problem.
Competing interests: No competing interests
The medical establishment began thousands of years ago with
altruistic motives of 'curing rarely, comforting mostly, but consoling
always". Rather, it all began basically to allay anxiety, relieve pain
and suffering of mankind. Lately, medical establishment seems to have
transformed itself into big business. The drug and technology people
seem to have invaded the medical profession in such a way that recent
studies published almost simultaneously in the leading British Journal
Lancet and the American New England Journal of Medicine show that medical
education is completely under the influence of drug and technology
As if that is not enough, lately reports are pouring in from
different sources showing how drug companies get medical scientists to
invent new diseases to sell their wares. This was going on in the past in
a more dignified but quiet style. Lately it has all come out in the open.
The ugliest one is the example of a new disease, "Female Impotence".3 Dr.
David Graham shows how even the FDA can easily be fooled by the Pharma
One could always confuse people with complicated statistics, anyway.
To achieve this end they attempt to medicalise human life at every stage
and create newer problems to sell their drugs. Researchers with close ties
to drug companies try to define and classify medical disorders at company
sponsored meetings. Practising doctors do not realize the attempts by
these drug giants to establish "normative data" for a range of
physiological measurements, like normal blood pressure, sugar, cholesterol
and sexual response etc. These levels keep changing almost by the day
depending upon the need for drug sales. Serum cholseterol level which were
at 150-250 mg % during my student days have come down below 200 mg lately.
I have not been able to find a good scientific reason for this fall except
that the cholesterol lowering drug market would have gone up by a few
billion dollars. Similar is the story with blood pressure levels and sugar
To give the reader the enormity of this problem a few such meetings
are cited here. A large gathering of "clinicians", "researchers", and drug
company representatives met for two days at the Cape Cod Hotel to "discuss
the future directions for research and clinical trials in the area of
female sexual dysfunctions against the backdrop of widespread lack of
agreement about its definition." 4,5
Since then many epidemiological studies have been "generated" to show
that anywhere between 49-80% of all women suffer from one of the above
mentioned sexual dysfunctions and the company claims that they could all
be helped by regular use of sildenafil. This is the similar story with the
definition of hypertension, hypercholesteraemia, hyperglycaemia and many
Earlier a similar campaign was mounted to sell expensive hormones
(HRT) to post menopausal women. It was made out that regular HRT use
after menopause would not only make life enjoyable, it would, at the same
time, prevent dangerous diseases of elderly women like bone loss and
fractures, heart attacks, cancers and what have you. The brainwashing of
doctors was such that the poor souls did not and could not think beyond
the artificial boundaries of the bio-medical model of man in this dynamic
universe, where Nature has a reason for everything but human reason cannot
comprehend all of it. If hormones were good for women after menopause,
why did Nature stop the secretion of such good a thing after menopause.
Now comes the revelation that long term use of HRT after menopause is
A glaring lacuna in the medical wisdom that affects the lives of
millions of hapless humans is in the arena of doctors trying to predict
the unpredictable future of apparently healthy people with the limited
knowledge of the phenotypical (body) features that the present bio-medical
model permits them to assess.8 Routine check up would dangerously damage
human health if doctors intervene with drugs or surgery to alter the
initial state of the partial knowledge obtained from screening, avers a
recent editorial in the leading British Medical Journal.9
I have written many times in the past on these problems but who cares
unless it comes from the Horse's pen (mouth).
"I don't give them hell, I just tell the truth and they think it is
Harry S. Truman.
1) Editorial. Drug company influence on medical education in USA.
Lancet 2000; 356: 781.
2) Marcia Angell. Is academic medicine for sale? N.Engl.J. Med 2000; 342:
3) Moynihan R. The making of a disease: female sexual dysfunction. BMJ
2003; 326: 45-47.
4) Special supplement. Int. J Impotence Res. 1998; 10: S1-S142.
5) Basson R, Berman J, Burnett A, et. al. Urology 2000; 163: 888-893.
6) Beral V, Banks G, Reeves G. Evidence from randomised trials on the long
term effects of hormone replacement therapy. Lancet 2002; 360 942-944.
7) Loeb T, editor. Cecil's Textbook of Medicine. 2002. Page 1202.
8) Firth WJ. Chaos-Predicting the unpredictable. BMJ 1991; 303: 1565-1568.
9) Stewart-Brown S and Farmer A. Screening could seriously damage your
health. BMJ 1997; 314 : 53
Competing interests: No competing interests