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Commentary
REVISTA PAULISTA DE MEDICIN A
Darie r’s dise ase : a ne w paradigm for
ge ne tic studie s in psychiatric disorde rs
• Ricardo So ares Silva
The recent news abo ut the sequencing o f the human geno me is still echo ing in the lay and scien-tific media, but the implied questio ns are already being fo rm u late d . Su c h q u e s tio n s always e vo ke th at archetypal scientist-who se-ambitio n-kno ws-no -limits, Dr Victo r Frankenstein, and his wish to create life by him s e lf ( whic h he ac c o m p lis he d , altho ug h the co nsequences are that’s ano ther sto ry).
But the wo rst temptatio n ensnaring us, do cto rs, is subtler and so mo re likely to be able to catch us and disto rt o ur wo rld-view. It is to try to superpo se the two ways o f understanding disease, the syndro mic-patho lo gical and the bio lo gical-genetic, and in the p ro c e ss, to c re ate a m o nste r as d e fo rm e d as the Creature o f Dr Frankenstein (witho ut the articulate and co herent way o f expressing itself that is described in the bo o k, I wo uld say...).
The p ap e r o n the ge ne tic c o -se gre gatio n o f depressio n presented in this editio n o f SPMJ po ints to wards this danger. The idea o f studying pairs o f diseases, where o ne o f them has a kno wn genetic pro file, in o rder to understand the genetic pro file o f the o ther, thro ugh their higher o r lo wer asso ciatio n, is clever, well-develo ped and clearly described, but there is a we ak sp o t in it. Und e r the ge ne ric nam e o f “depressio n” there are many kinds o f affective diso r-ders (bipo lar, with o r witho ut psycho sis, seaso nal, etc.), each o ne with a different pattern o f evo lutio n, respo nse to treatment and genetic transmissio n, and so it is necessary to define which depressio n co -segregates with Darier’s syndro me.
And that is the po int. The classificatio n o f all these diso rders under the co mmo n name o f
depres-sio n is useful fo r the co mprehendepres-sio n o f their co mmo n characteristics, internally co herent and a legitimate way o f understanding them. All the systems o f disease classificatio n in use (ICD-10, MSD-IV), altho ugh having imprecisio ns and co ntro versial po ints, are based o n synd ro m ic tho ught, c linic al o b se rvatio n and the gro uping o f diseases by their similarity, and they have served us well fo r a lo ng time.
It is no t likely that genetics will defeat the clas-sificatio n systems no w in use, fo r the reaso ns set o ut abo ve. Ho wever, fro m the mo ment that there is a clear definitio n o f what diseases are o f genetic o rigin and what are no t, the re will the n arise an impulse fo r refo rmulating the system, separating the two gro ups with o u t re g a rd fo r th e ir c o m m o n c lin ic a l characteristics (what will happen to the mo tto , “clinic rules”?). Against this, I wo uld like to suggest so me-thing like MSD-IV, in which diagno sis is expressed alo ng five axes: psychiatric diso rders, develo pmen-tal diso rders, systemic co nco mitant disease, level o f relevant stress facto rs, and level o f lo ss o f functio n – and m ayb e a s ixth axis , ge ne tic fac to rs , with a mo difier to indicate whether it refers to axis I, II o r III...?
The majo r advantage o f a multi-axial system is that it reco gnizes the existence o f multiple agents (o rganic, psychic, enviro nmental) acting o n the bio -psycho -so cial syste m we call hum an and causing disease. This wo uld validate bo th visio ns, o rganicist and psycho so cial, and (it is to be ho ped) sto p their tireso me co nflict by satisfying bo th sides (o r, as the Creature said, “Make me happy, Master, and I will be virtuo us”).
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Just o ne mo re lo o k at Frankenstein: he admit-tedly made the Creature big because o f the technical difficulties o f micro -sutures – and that is the lesso n fo r us. The elegance, co nciseness and efficiency o f the new classificatio n system will depend o n the precisio n o f tho se who will have the missio n o f integrate the
find ings fro m ge ne tic re se arc h with the p re se nt medical kno wledge. Go o d luck to them!
Ricardo Soare s Silva. Psychiatrist, University Ho spital, Universidade de São Paulo , São Paulo , Brazil.
