The Missing Gene (2006)

The Missing Gene: Psychiatry, Heredity, and the Fruitless Search for Genes

Algora Publishing. Available from $26.95.

Chapter-By-Chapter Summary of The Missing Gene (PDF)

The Missing Gene provides a much needed critical appraisal of this body of research. Proponents of theories based on this research have long held that psychiatric disorders are caused by a genetic predisposition in combination with environmental agents or events. In the past few decades, researchers have attempted to pinpoint genes at the molecular level. However, the field of psychiatric genetics is approaching a crisis due to the continuing failure, despite years of concerted worldwide efforts, to identify these presumed genes. Unfortunately, the popular media frequently—yet erroneously—reports that genes for the major psychiatric disorders have already been discovered. In fact, researchers’ initial “discoveries” are rarely confirmed in replication studies.

The search for the genes researchers believe underlie psychiatric disorders is based on previous studies of families, twins, and adoptees. However, Joseph shows that these studies provide little if any scientifically acceptable evidence in support of genetics. 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 the way in which 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.”

Joseph 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 researchers cite 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 had a profound impact on both scientific and public thinking, as well as on social policy decisions. In addition, genetic theories influence the treatment approaches of clinicians working with people diagnosed with psychiatric disorders. Yet, as the Joseph demonstrates, these theories do not stand up to critical examination.

Like the author’s previous work, The Gene Illusion, this is a controversial book, and is sure to spark intense discussion among people interested in the causes of psychiatric disorders. As in The Gene Illusion, Joseph 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 and inaccurate accounts of the research put forward in support of genetics. He 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 major role in public and scientific discourse on the role of heredity in causing psychiatric disorders.

Table of Contents

CHAPTER 1: Introduction. The Twin Method: Science or Pseudoscience?
CHAPTER 2: ADHD Genetic Research: Activity Deserving of Attention, or Studies Disordered by Deficits?
CHAPTER 3: A Critique of the Spectrum Concept as Used in the Danish-American Schizophrenia Adoption Studies
CHAPTER 4: Pellagra and Genetic Research
CHAPTER 5: A Generation Misinformed: Psychiatry and Psychology Textbooks’ Inaccurate Accounts of Schizophrenia Adoption Research
CHAPTER 6: Irving Gottesman’s Schizophrenia Genesis: A Primary Source for Misunderstanding the Genetics of Schizophrenia
CHAPTER 7: Autism and Genetics: Much Ado About Very Little
CHAPTER 8: The 1942 “Euthanasia” Debate in the American Journal of Psychiatry
CHAPTER 9: The Twin Method’s Achilles Heel: A Critical Review of the Equal Environment Assumption Test Literature
CHAPTER 10: Bipolar Disorder and Genetics
CHAPTER 11: Genotype or Genohype? The Fruitless Search for Genes in Psychiatry