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Education And Debate

Efficacy of antidepressants in adults

BMJ 2005; 331 doi: https://doi.org/10.1136/bmj.331.7509.155 (Published 14 July 2005) Cite this as: BMJ 2005;331:155

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Fallacy in The Hamilton Rating Scale

Sir,

The article uses the scores of the Hamilton Rating Scale for
Depression to criticise the belief that anti-depressants have some
efficacy. In my opinion there is a fatal flaw at the heart of the Hamilton
Scale. Hamilton put together behaviours that he regarded as symptoms so as
to describe a syndrome that he calls DEPRESSION. He then faced the
difficulty of quantifying the qualitative. We are or rather were a
nautical nation. It is easy to use the metaphor such as 'depth' to
conceive of the intensity of depression. There are no units of measurement
for depression such as fathoms or metres but not deterred he constructed a
scale using the symbols that when used normally stand for natural numbers
such as 0,1,2,3,4. This metaphorical scale now stands for the metaphorical
depth.

However 0,1,2,3,4 do not represent numbers but are symbols in a
code whereby 0 = absent,1 = mild, 2 = moderate, 3 = severe and 4 =
incapacitating.You cannot add up these code symbols as if they are natural
numbers!You can creat as valid a code with 4 = absent, 2 = mild 1 =
moderate, 0 = severe and 3 = incapacitating. This second code is just as
valid as the other but you can see now how ludicrous it is in this case to
try and add the symbols 01234 as if they were numbers. In the days when
one sent information by Telegraph and paid by the word it would be
economic to construct a code whereby the code 'number'for the intensity of
each symptom would be sent always in the same order on the telegraph
message. However you would be very foolish to 'add up' all those code
symbols in the Hmilton Rating Scale to try give a score. A profound loss
of information but also a grave lapse in logic. I fear the authors of this
paper have been on a bit of a wild goose chase in so far as they used The
Hamilton Rating Scale in their argument.

Competing interests:
None declared

Competing interests: No competing interests

29 July 2005
David H. Marjot
Consultant Psychiatrist.
rrey. KT13 8NF