Jay Joseph Psy.D. The Missing Gene (original) (raw)

What causes psychiatric disorders to appear? Are they primarily the result of people’s
environments, or of their genes? Increasingly, we are told that research has established the
importance of genetic influences on psychiatric disorders such as schizophrenia, bipolar disorder,
autism, and attention-deficit/hyperactivity disorder (ADHD).
The Missing Gene provides a much-needed critical appraisal of theories supporting a genetic
basis for psychiatric disorders. These theories hold that psychiatric disorders are caused by a
genetic predisposition in combination with environmental agents or events. In fact, the field of
psychiatric genetics is approaching a crisis due to the continuing failure, despite years of concerted
worldwide efforts, to identify the genes presumed to underlie the major mental disorders.
The belief that such genes exist is based on studies of families, twins, and adoptees. However,
the author shows that, contrary to accounts in popular works, these studies provide little if any
scientifically acceptable evidence in support of genetics. Moreover it is not true, as frequently
reported in the popular media, that genes for the major psychiatric disorders have already been
discovered. In fact, researchers’ initial “discoveries” are rarely replicated. As this becomes more
understood, and as fruitless gene finding efforts continue to pile up, we may well be headed towards
a paradigm shift in psychiatry away from genetic and biological explanations of mental disorders, and
towards a greater understanding of how family and social environments contribute to human
psychological distress. Indeed, Kenneth Kendler, a leading twin researcher and psychiatric geneticist
for over two decades, wrote in a 2005 edition of the American Journal of Psychiatry that the “strong,
clear, and direct causal relationship implied by the concept of ‘a gene for …’ does not exist for
psychiatric disorders. Although we may wish it to be true, we do not have and are not likely to ever
discover ‘genes for’ psychiatric illness.” And Peter Propping, recipient of the 2004 Lifetime
Achievement Award from the International Society of Psychiatric Genetics, wrote in 2005 as follows:
“Whereas genetically complex traits are being successfully pinned down to the molecular level in other
fields of medicine, psychiatric genetics still awaits a major breakthrough.”
The author devotes individual chapters to ADHD, autism, and bipolar disorder, where he argues
that, contrary to the frequent claim that these conditions are “heavily genetically influenced,” there
exists little evidence that they have a genetic foundation. Looking specifically at autism, despite the
near-unanimous opinion that it has an important genetic component, the evidence cited in support of
this position is stunningly weak. It consists mainly of family studies, which cannot disentangle the
potential influences of genes and environment, and four small methodologically flawed twin studies
whose results can be explained by non-genetic factors. Not surprisingly, then, over a decade of
autism gene finding research has come up empty.
The Missing Gene is an important book because theories based on genetic research have a
profound impact on both scientific and public thinking, as well as on social policy decisions. In
addition, genetic theories influence the types of clinical treatments received by people diagnosed with
psychiatric disorders. Yet, as the author demonstrates, these theories do not stand up to critical
examination.
Like the author’s previous work, T he Gene Illusion: Genetic Research in Psychiatry and Psychology Under the Microscope, this will be a controversial book, and is sure to spark intense
discussion among people interested in the causes of psychiatric disorders. As in The Gene Illusion,
the author challenges many positions viewed by mainstream psychiatry and psychology as
established facts. In the process, he shows that textbooks and other authoritative sources sometimes
provide misleading or inaccurate accounts of the research put forward as supporting the genetic
position. The author concludes that it is unlikely that faulty genes play a role in causing the major
psychiatric disorders.
The Missing Gene provides an enormously important alternative to currently popular genetic
theories in psychiatry. It is destined to play an important part in public and scholarly discussions of
genetic factors’ possible role in causing human psychological distress.