Nurture states its case
Even the most ardent ‘nature’-lover would have to concede that the genetic contribution to schizophrenia or other psychiatric illness cannot explain 100% of the risk. However, those who support the ‘nurture’ side of the story seldom make any acknowledgement of the fact that a family history of mental illness presents the greatest risk to an individual.
This latter entrenched opinion is the subject of this post.
At the end of least year an article was published in the Guardian newspaper in the UK. Written by the psychologist Oliver James it championed the work of a New Zealand psychologist, John Read. Read’s work has recently been further highlighted by its airing at recent conferences co-presented with a Manchester researcher, Paul Hammersley.
In brief, they propose that the experience of abuse (predominantly sexual) during childhood, in combination with negative or confusing maternal behaviour (dubbed ‘mystifying’ behaviour) is a/the major cause of schizophrenia.
There is an excellent summary of the points of the paper from the clinical stand-point at schizophrenia.com including a clear rebuttal/criticism and subsequent reply from Read.
I cannot add much to this with regard to the comments on the clinical details. However, there are a number of other points that I think this issue raises.
1) Although a number of other means of abuse are mentioned by the authors, sexual abuse appears to be the crux of their new theory. While no-one would belittle the horror of such criminal acts against children, it is hard for me to understand the specificity of its action in causing schizophrenia in young adulthood. In other words, why don’t the myriad of other forms of childhood misery (death of a parent, divorce, chronic illness, neglect, bullying at school, exam stres etc. etc.) also result in schizophrenia. And why doesn’t sexual abuse result in other psychiatric conditions equally…indeed, there is some evidence that it does.
2) Added to the ’sexual’ dimension of the argument is the role of maternal ‘mystification’ in pushing children towards future schizophrenia. This seems very similar to early theories surrounding the role of the mother’s personality in triggering autism and schizophrenia in her children.
Because this has echoes of the Freudian school of thought, alarm bells immediately ring. Interpretational swings tend to be a feature of social sciences and the humanities rather than ’science sciences’. Text books are written and re-written according to the current fashionable mind-set. For example, in archaeology, research has been directed by the processual and then the post-processual schools of thought. I would argue that science is data-driven rather than interpretation-driven. That’s not to say that emerging data doesn’t change the predominant thoughts of the field, but rather that this process is not moulded to fit a pre-existing model. So my criticism from this point of view is that perhaps the psychologists not only have pre-conceived ideas of the basis of schizophrenia but also have an ideological position to defend. In all honesty, I have to counter this criticism somewhat by noting that mouse models of behavioural disorders sometimes feature (genetically dictated) failures in nurturing/nesting. In fact Prof. James Watson (yes, that one) in an online lecture described the work of Simon Baron-Cohen (yes, the father of that other one) that seems to suggest a genetic effect on parenting that might contribute to autism in children…I haven’t had a chance to look up the source material myself yet.
3) It’s been mentioned before but there is a danger that a culture of parental blame could result from a theory such as this. Moreover, if the link between schizophrenia and child abuse is considered so strong, would this diagnosis be considered a suitable trigger for the instigation of criminal investigations?
4) If, as the authors claim, the link between sexual abuse and schizophrenia is a ‘risk’ effect then perhaps the sample sizes investigated in the cross-fostering study are on the small size. In genetic case-control association studies on complex disorders (i.e. looking for genetic ‘risks’) it is generally thought appropriate to look at hundreds of cases rather than tens (as in their study), in order to be able to discriminate real signals from random noise.
5) The rather evangelical and dismissive tone of the press releases and original Guardian article is not often observed from scientists. They clearly feel passionately about their subject and the perceived sea-change in schizophrenia understanding it represents. However, the frontal attack on biological science was probably a tactical error as it erects barriers that were probably not there in the first place. The last example of vociferous backing of an anti-science hypothesis was in the form of the Intelligent Design fiasco earlier this year. In that case too, the proponents relied far too heavily on the statement that ‘evolutionary science can’t explain everything’. In the case against biological psychiatry, the often picked up on statements from various luminaries (who should know better) that no biological markers or genes are known for schizophrenia, have been used to batter the biological side of the argument. My reply would be:
a) those are old statements describing a young science (see first post) - people haven’t been keeping up with the literature.
b) saying there aren’t any now is not the same thing as saying there won’t be any soon. Science is a slow, progressive process but there is nothing to suggest that, in this instance, it is heading in the wrong direction.
6) Finally, here I am trying to defend my career-choice in the face of those telling me I’m wasting my time! While I am confident that the field of molecular psychiatry will earn its appropriate place in the end, it is a very sobering prospect that there are many that seem to feel as if the acceptance of a biological root cause of psychiatric illness is another example of some state-controlled removal of free will or some license for blanket prescription medication. Personally, I have no conceptual problem in accepting that my character, my thoughts and feelings are all the result of processes in my brain and that, because that organ is a biological entity, it is going to be subject to the vagaries of my DNA inheritance and life-time experience. Treating a malfunctioning organ is no different if that organ absorbs oxygen into the bloodstream (lungs) or is responsible for our thoughts (our brains).