Nuclear Genetics

Researchers recently completed a first of its kind, large-scale international survey of attitudes about mental health and they were surprised by the results. According to their analysis published in this month’s issue of the Journal of Affective Disorders, people in developed countries, like the United States, are more likely to assume that ‘mental illnesses’ are similar to physical illnesses and biological or genetic in origin, but they are also much less likely to think that individuals can overcome these challenges and recover

The National Institute of Mental Health (NIMH) is increasingly shifting its research emphasis toward attempting to uncover biomarkers for “mental diseases,” which may have dramatic consequences for research and training in clinical psychology. In an article to be published in next month’s Professional Psychology: Research and Practice, Marvin Goldfried outlines how the shift in funding priorities for psychological research is tied to the needs of pharmaceutical companies and the biological model in psychiatry.

Human behavioral genetics and its allied field of psychiatric genetics are in trouble, as unfulfilled gene discovery expectations during the “euphoria of the 1980s” have continued to the present day, leading to researchers’ “nonreplication curse” dysphoria of the 2010s. In my recent book The Trouble with Twin Studies: A Reassessment of Twin Research in the Social and Behavioral Sciences, I presented a detailed argument that genetic interpretations of the common “classical twin method” finding that reared-together MZ twin pairs resemble each other more (correlate higher) for behavioral characteristics than do reared-together same-sex DZ twin pairs are invalid because, among other reasons, the twin method’s crucial MZ-DZ “equal environment assumption” (EEA) is false.

While a great deal of the excitement about advances in psychological treatments comes from the potential for research in neuroscience to unlock the secrets of the brain, many mental health experts would like to temper this enthusiasm. A special issue of the Behavior Therapist released this month calls into question the predominant conception of mental illnesses as brain disorders.

There seems to be no end to illogical and even comical “findings” from MZ-DZ twin method comparisons, where the original twin researchers argue that the greater behavioral resemblance of reared-together MZ (monozygotic, identical) versus same-sex DZ (dizygotic, fraternal) twin pairs demonstrates the “heritability” of the behavioral characteristic in question. Among these we find a twin study whose authors concluded in favor of a genetic basis for being a “born again Christian” (65% heritability), another that found important genetic influences on tea and coffee drinking preferences, and still another that found that the heritability of “loneliness in adults” is 48%.

In a 1992 essay, British psychiatric genetic researcher Michael Owen wondered whether schizophrenia molecular genetic research would become the “graveyard of molecular geneticists.”1 Owen predicted that if major schizophrenia genes existed, they would be found within five years of that date. He was optimistic, believing that “talk of graveyards is premature.”2 Owen now believes that genes for schizophrenia and other disorders have been found, and was subsequently knighted for his work. Despite massively improved technology, however, decades of molecular genetic gene finding attempts have failed to provide consistently replicated evidence of specific genes that play a role in causing the major psychiatric disorders.

The psychiatric genetics literature contains few references to specific environmental factors that cause psychiatric disorders, and while researchers acknowledge a role for these factors, they usually claim that environmental causes are mysterious or unknown. As a leading group of psychiatric genetic researchers recently put it, while claiming that schizophrenia “has a substantial genetic contribution,” the “underlying causes and pathogenesis of the disorder remains unknown.” But research suggests otherwise.

If molecular genetic research had actually delivered the genes for psychiatric disorders promised by mainstream psychiatry and its subfield of psychiatric genetics, twin research today would be largely obsolete because focus would have shifted to molecular genetic research, and a person’s genotype and diagnosis would be determined directly from his or her DNA. Twin research, therefore, retains its current level of importance in psychiatry only because the genes believed to exist for its disorders, based largely on genetic interpretations of twin studies, have not been found.

In the light of the much trumpeted claims that recent research has identified genes for schizophrenia, it is important to review the track record of this type of endeavor. Despite thousands of studies costing millions of dollars, and endless predictions that the genetics of schizophrenia would shortly be revealed, the field has so far failed to identify any genes that substantially increase the risk of developing schizophrenia.

Research from the Semel Institute for Neuroscience and Human Behavior at USC finds that "The standard concept of genetic testing includes at least three...

An NBC online News article dated October 15, 2010, carried the noteworthy title New blood test may help detect schizophrenia. The article was written by Natasha Allen, a freelance medical journalist. The gist of the article is that there is a new blood test called VeriPsych which "researchers say" is 83% accurate in discriminating people who are "schizophrenic" from people who are not.

On November 12, 2013, Molecular Psychiatry published online Evidence That Duplications of 22q11.2 Protect Against Schizophrenia, by Rees et al. The print version was published last month – January 2014. The idea of a genetic mutation that would protect one from schizophrenia aroused a good deal of interest and enthusiasm. The paper has added some impetus to psychiatry's claim that the condition known as schizophrenia is a genetic disease. For this reason, I thought it might be helpful to take a closer look at the study.

Although psychosis is more common in the parents of people with psychosis than those without, the difference cannot be attributed to genetics, research from...

Research from the universities of Cardiff, Cambridge and Bristol finds no evidence of a link between genetic associations with schizophrenia and adolescent psychotic experiences....

According to a leading group of psychiatric genetic researchers, writing in 1999, “From the perspective of psychiatric genetics, the Human Genome Project is an immense factory producing and refining the tools we will need to discover the genes that cause mental illness.” A 2002 “speculative outline” by a group helping to revise the DSM envisioned a future DSM-5 practice of classifying disorders on the basis of "the patient’s genotype, identifying symptom- or disease-related genes, resiliency genes, and genes related to therapeutic responses and side effects to specific psychotropic drugs.” A dozen or so years ago, at least some of the DSM-5 architects believed that genes would at long last be identified and would be integrated into the next version of the DSM. As we know, this did not happen.

Psychiatric molecular genetic research has failed to discover genes that underlie the major psychiatric disorders, the existence of which twin and adoption studies are assumed to have established. "Genome-wide complex trait analysis" (GCTA) was developed a few years ago as a means of solving what researchers call the "missing heritability" problem. One researcher believed that the new GCTA method would “drive a stake through the heart of” criticism of behavioral genetic theories and methods, and would finally put criticism of twin studies “to rest.” The opposite scenario appears to be playing out, however, as leading behavioral genetic and psychiatric genetic researchers struggle to prevent some recent negative GCTA findings and the obvious false assumptions underlying twin research from driving a stake through the heart of twin studies themselves.

As most readers are aware, it is widely believed that both within and without of psychiatry genetic factors play an important role in causing major psychiatric disorders such as schizophrenia, bipolar disorder, major depression, ADHD, autism, anxiety, and even post-traumatic stress disorder (PTSD). Twin studies provide the main pillar of support for this belief which is often, though mistakenly, presented as a scientific fact.

On February 28th, the New York Times reported the latest psychiatric disorder “gene finding” claim in an article entitled “5 Disorders Share Genetic Risk Factors, Study Shows,” The Times reporter described a study that claimed to have identified shared genes associated with five psychiatric disorders: autism spectrum disorder, attention/deficit-hyperactivity disorder (ADHD), bipolar disorder, major depressive disorder, and schizophrenia. We have seen thousands of such claims in psychiatry since the 1960s, and we have also seen that these claims do not survive replication attempts.

Researchers from the University of Cambridge have found, for the first time, that genes affected by stress during life can be passed to the...

As the schizophrenia/psychosis recovery research continues to emerge, we discover increasing evidence that psychosis is not caused by a disease of the brain, but...

A study of 566 families with 1416 bipolar-disordered members, and 675 families with 1726 depressed members by researchers from Johns Hopkins and the University...

A comprehensive review of research on the genetics of depression up to 2012, published online today by Psychological Bulletin, finds "a continued lack of...

In a study released June 6, 2012 through the online journal Behavioral and Brain Functions, researchers from Japan acknowledge that "the results of association...