Abstract
Peter W. Jepsen: Mental Health and Mental Disease Models
I. Health and Disease
The fundamental ethical questions about mental disorders are whether these are just conditions that
are disliked by the society – ‘suiting the needs of those in power’, or, if there is, on the other side,
anything ‘real’ about mental disorders. If yes, what is it that ‘really’ exists?
Three possible answers to these questions are presented. According to the first disease symptoms
are ‘symptoms’ of something, namely an underlying biological dysfunction. This position is in
accordance with the philosophical position called realism. Modern biomedicine reflects this kind of
thinking. According to the next main position disease symptoms are nothing but what we see and
describe from the outside. Symptoms are, therefore, not ‘symptoms’ of anything. This position
follows the philosophical position called empiricism. Modern classification systems (DSM-III/IV,
ICD-10) reflect empiristic thinking. The last main position holds that mental ‘disease’ is either a
strictly individual phenomenon (first person phenomenology) or – in its most radical form - the
reflection of a disordered society (anti-psychiatry). We call this position anti-realism.
Realism regards health as absence of disease. A disease is a type of internal state of an organism
which interferes with the performance of some natural function i.e. some species-typical
contribution to survival and reproduction, and is atypical of the species, or, if typical, mainly due to
environmental causes. This concept of disease is considered value-neutral i.e. purely scientific (1;2).
The problem is, however, if it makes sense in psychiatry.
Empiricism regards health (and disease) as manmade constructions i.e. non-scientific conceptions,
dependent of values of what should count as a normal (or non-normal) life (normative normality).
This makes normality relative to time and place, and religious and political opinions. There is no
sharp demarcation between health and disease.
Anti-realism focuses on the individual subject and its ’problems’ rather than on a class of subjects
with common ’problems’. There are no other criteria for disease than the subjective feeling of being
ill and no clear distinction between health and ’disease’.
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II. Disease Models
There is an ongoing debate concerning the way that mental illnesses should be classified. There are
two aspects to this: (I) which conditions get classified as mental illnesses rather than normal
conditions, and (II) among those conditions we agree are mental illnesses, how they are grouped
together into different kinds (3). Diseases can be classified as etiological entities, as descriptive
entities, as one or more continua or one could totally reject the idea of classification (anti-realism).
We can describe at least six main approaches to psychiatric classification.
The bio-medical model regards diseases as objective realities in nature. This is the realistic
approach. Diseases are anatomical-clinical entities i.e. constellations of specific signs, symptoms
and pathology and with specific etiology, course and prognosis. Biological explanations are
ontologically primary. This means that in a biological-psychological-social causation chain
biological explanations are preferred for psychological or social explanations.
The clinical-descriptive model regards diseases as empirical facts. Diseases are manmade
constructions that are characterized by their common, external phenomena i.e. the symptoms. The
existence of a given syndrome depend to a certain extend on and only on our definition of the
syndrome. This is the empiristic approach. Definitory syndromes, therefore, do not necessarily
correspond with natural kinds i.e. a reality in nature. When descriptive diagnostic categories are
used for research purposes this should be considered a problem.
The bio-psycho-social (epidemiological) model (4) holds that in a biological-psychological-social
causation chain biological, psychological, and social causes have equal weight i.e. causes can be
identified ’inside’ as well as ’outside’ the body. This model, therefore, is useful in epidemiologic
research. The bio-psycho-social model could be called a mixed model.
Continuum of disease model. This view implies that diseases are continua, spectra or expressions
or stages of one and the same disease process (Einheitpsychose (unitary psychosis), Griesinger).
There is no boundary between diseases and disease classification makes no sense. There is no sharp
demarcation between health and disease and it is often unclear whether or not normality is included
into a given spectrum. This view is increasingly popular, but scientifically unproven and clinically
impractical (5). The bio-medical model, the clinical-descriptive model, the bio-psycho-social model
and the continuum model all have in common that medicine is regarded a natural science. In
contrast the next three models to be described have their roots in the human sciences.
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The psychodynamic model holds that ’disease’ is the result of unconscious intrapsychic conflicts
or repressed infantile sexuality. Disease symptoms can be understood or interpreted but not causally
explained. Disease symptoms are thought to serve an unconscious purpose. As a scientific theory
this model remains unproven.
Holistic models hold that ’disease’ is a reflection of alleged physical, mental, social or
environmental ’unbalances’. Examples are iridology, acupuncture, chiropractic, homeopathy and
herbal medicine (6). Theory as well as treatment evidence is based on observation and treatment of
individual subjects i.e. a treatment would be claimed effective even if had only helped one single
person. Historically holistic models have their roots in pre-scientific medicine. The psychodynamic
model and the holistic models express first person phenomenology.
The social-psychiatric view in its most radical form claims that psychiatric classification depends
solely on the values of those doing the classification, that there is nothing objective about it at all,
and that there are no facts about what is normal (anti-psychiatry) (3).
Conclusion
Only the bio-medical model offers value-neutral concepts of health and disease. All other concepts
of health and disease in medicine as well as in psychiatry are more or less value-laden which opens
up for introduction of controversial diagnostic categories or, no less controversial, removal of
diagnostic categories after lobbying from activist groups. Mental disorders are increasingly seen as
brain disorders according to the bio-medical model. It may, however, be meaningful to maintain a
distinction between the psychological and the biological ways of understanding people’s illnesses,
but no particular illness is purely mental or purely physical (3).
Peter W. Jepsen, MD, Phd.
Consultant psychiatrist
Direct: +45 38 64 46 11
Mail: peter.jepsen@regionh.dk
The Capital Region of Denmark
Mental Health Services
District Psychiatric Centre Rigshospitalet University Hospital
96, Strandboulevarden
DK-2100 Copenhagen Ø
Tel: +45 38 64 46 46
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Reference List
(1) Boorse C. Health as a theoretical concept. Philosophy of Science 1977;44:542-73.
(2) Boorse C. On the distinction between disease and illness. Philosophy and Public Affairs
1975;5:49-68.
(3) Perring C. Mental illness. In: Zalta EN, editor. The Stanford Encyclopedia of Philosophy.
Spring 2010 ed. 2010.
(4) Engel GL. The Need for a New Medical Model: A Challenge for Biomedicine. Science 1977
Apr 8;196(4286):129-36.
(5) Lawrie SM, Hall J, McIntosh AM, Owens DG, Johnstone EC. The 'continuum of psychosis':
scientifically unproven and clinically impractical. Br J Psychiatry 2010 Dec;197(6):423-5.
(6) Stalker D, Glymour C. Engineers, cranks, physicians, magicians. In: Stalker D, Glymour C,
editors. Examining holistic medicine.Buffalo, New York: Prometheus Books; 1989.
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