A Myth in Creation

Jay Joseph's guest post on Duncan Double's blog – criticizing the notion that schizophrenia has a substantial genetic component – reminds me of the distinction between progressive and degenerative scientific programs from philosophy of science. Progressive scientific programs show a growth of theoretical frameworks, development of new research methods, generation of novel findings, and validation of predictions. Degenerative programs lack these features; instead, they are engaged in the never-ending task of explaining away findings. I marvel at the vacuousness of the efforts to deny the overwhelming scientific consensus that a substantial portion of the risk of development of schizophrenia comes from aggregate genetic factors, and that these genetic factors don’t confer this risk in isolation but rather through complex interactions with non-genetic and environmental factors. In order to appreciate the progressive nature of genetic research into the nature of schizo...

This post is in response to Duncan Double's commentary on Ken Kendler's paper " The dappled nature of causes of psychiatric illness : replacing the organic–functional/hardware–software dichotomy with empirically based pluralism". I disagree with much of Double's characterization and interpretation of Kendler's paper and I find the responses wholly inadequate. Unpacking and addressing each and every point will take a long time, so for the purposes of illustration of the inadequacies of Double's comments, I'll consider his response to the discussion of aggregate genetic effects. To demonstrate what aggregate genetic effects are, let's look at what Kendler writes about schizophrenia: "Adoption and twin studies show consistent and strong evidence for aggregate genetic effects in schizophrenia with the best estimates of heritability being quite high (~80%).34 To date, only a very small proportion of this risk has been indexed by known molecul...

I have recently between engaged in a twitter discussion with Duncan Double (a retired British psychiatrist), who insists on using the organic/functional distinction when it comes to psychiatric disorders and seems to think that this distinction justifies the claim that functional psychiatric disorders have no biological causes and have only psychosocial causes. In order for this debate to go anywhere, I think we need to be very specific about the meaning of the terms. What exactly does “functional” mean? For the record, I am not in favor of using the term “functional” as a general descriptor for psychiatric conditions. I think it is too conceptually muddled and has a lot of unsavory philosophical baggage. Nonetheless, I need to define it first if I am to meaningfully discuss the concept. I think there are two broad ways of defining the term "functional". Meaning 1 (M1): A psychiatric condition is functional if it cannot be attributed to an “independently...