Schizophrenia : the epigenetic puzzle / Irving I. Gottesman, James Shields, with the assistance of Daniel R. Hanson.

  • Gottesman, Irving I.
Date:
1982
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Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Schizophrenia : the epigenetic puzzle / Irving I. Gottesman, James Shields, with the assistance of Daniel R. Hanson. Source: Wellcome Collection.

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    242 Schizophrenia: the epigenetic puzzle liability is known; the most likely environmental contributor, stress, may come from many sources and, apparently, may come during any stage of development. Prenatal or birth complications, early deprivations, broken homes, censuring parents, the death of someone close, failures in school, poor work or social relations, childbirth, a bad drug trip, as well as all kinds of good fortune may have effects on a predisposed individual that are obvious only in retrospect. In prospect, it will be impossible to prophesy the events themselves, let alone their effects. A useful mental exercise for those concerned about the etiology of schizophrenia is to ask themselves the following questions about putative etiological factors: Do the factors lead to cost-effective percentages of true and false positives and true and false negatives? Is the factor one-way pathognomonic in that its presence rules in schizophrenia? Is it two-way pathognomonic in that its presence rules in schizophrenia and its absence rules out schizophrenia? The answers to these questions will suggest whether putative etiological factors have a strong influence on schizophrenia or are merely moderator variables (Meehl, 1977). If we wanted to conjure up a futuristic - if impossible - experimental design so as to resolve most of the questions raised by the studies and strategies we have reviewed, we would need a prospective longitudinal study of identical and fraternal twins who were offspring of well-characterized (biologically and psychologically) dual-mating schizophrenics. One twin in each pair would be kept by the biological parents and the other would be adopted at birth into a good home with well-studied adoptive parents. Of course, the study would commence with the conception, monitor fetal heart- rate changes to stress, and would include a battery of serial, noninvasive biological and psychological examinations at the cutting edge of their respective subdisciplines over a 30-year period. Reprise Our present knowledge, despite elements of uncertainty, permits us to conclude unequivocally that genetic factors are importantly involved in the etiology of schizophrenia. Some of the factors are probably specific. By specific we mean that some genes, whatever other effects they have on other traits, contribute to the liability of developing schizophrenia rather than, or more than, they do to, say, cholesterol levels, diabetes, eye color, or anxiety neurosis. The specific schizophrenia-related genes are posited to be differen- tiable from the general genetic contributors to the total liability, with the latter serving as modifiers or potentiators. Regrettably, no individual