Classifying Madness: Criticisms and Alternatives

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Over the years, Vincent van
Gogh’s mental illness has been classified in 30 different ways by over 150
different physicians, not just those who originally treated him. It is becoming
clear that, in the classification of madness, this is far from an isolated
example. Amongst the ranks of both psychiatrists and clinical psychologists are
those who argue for a radical rethink.
Richard P. Bentall, a clinical
psychologist and Professor of Experimental Clinical Psychology at the
University of Manchester, recently published ‘Madness Explained‘, an attempt to
wrestle descriptions of madness away from rigid categorisation as well as
provide an alternative. In this, the first of a series of posts, I will discuss
Bentall’s criticisms of the major categories of mental illness.
The Categorisation of Madness
Traditional psychiatric
practice has placed madness in a number of different categories. Two well-known
examples of these categories are bipolar disorder – what used to be called
manic depression – and schizophrenia. These categories, along with a host of
others, are used by many mental health professionals as both a shorthand
description of mental illness, and a guide to treatment.
Reliability and Validity
There are two simple criteria
used by scientists to measure, amongst other things, whether a system of
diagnosis is useful: these are its reliability and its validity. Reliability
refers to whether different doctors give the same diagnosis to the same person
with the same symptoms. The validity of a diagnosis is a measure of whether it
describes what it is supposed to describe. In other words, if you were a doctor
and I told you someone you are about to meet is schizophrenic, then, broadly,
you would not be surprised by the symptoms they exhibited.
Bentall argues psychiatric
diagnoses are neither particularly reliable, nor particularly valid. Here is
why.
Not Reliable
Reliability studies of
different classification systems are many and varied. One typical study is that
carried out by, amongst others, Robert Spitzer, a strong proponent of the DSM
classification system. This study found only modest agreement between specially
trained psychiatrists of the same patients – and these results were obtained
under ideal conditions, probably not representative of the average busy
clinician.
To pick any single study as
representative of the whole is not very scientific. Bentall, however, who has
evaluated many of them, argues that, in general, the research has been less
than convincing. Many studies even fail to reach the minimum statistical
criteria for reliability.
Not Valid
While there are 201 different
diagnoses in the DSM-IV, arguably the most established distinction in
psychiatric classification systems is between schizophrenia and bipolar
disorder. To question this distinction is not merely to attack a straw man –
the difference is fundamental. Nevertheless the research has seriously
questioned whether there is a clear dividing line between the two diagnoses.
Kendell & Gourlay (1970)
examined the symptoms of nearly 300 patients with diagnoses of either
schizophrenia or manic depression – now referred to as bipolar disorder. If the
prevailing system of classification is correct then we should see two distinct
groups of symptoms. What the study actually found was a continuum of symptoms,
with most patients falling in the middle. They had some symptoms typical of
schizophrenia and some typical of manic depression. Subsequent research has
provided similar evidence of the poor validity of current systems of
classification.
So What?
Why, then, is it important
that classification systems are valid and reliable? What are the alternatives?
Can madness be cured? All questions for future posts…
About the author


Psychologist, Jeremy Dean, PhD
is the founder and author of PsyBlog. He holds a doctorate in psychology from
University College London and two other advanced degrees in psychology.
He has been writing about
scientific research on PsyBlog since 2004. He is also the author of the book
“Making Habits, Breaking Habits” (Da Capo, 2003) and several ebooks.





SOURCE: PSYBLOG
Kayode Ojo
Kayode Emmanuel Ojo is the Co-Founder and Managing Director at SHEFFA Limited. He is presently studying Computer Science at the National Open University, Victoria Island, Lagos.