The Causes of Schizophrenia: It ’ s Probably Not Genetics

For more than a century, researchers have had a deeply-held belief that schizophrenia is one form of mental illness that has its basis in genetics. In the intervening years, hundreds of millions of person-hours and billions of dollars have been funneled pursuing the genetic theory of schizophrenia. Despite all of this enormous effort, researchers are starting to understand that perhaps the genetic component of schizophrenia has been overemphasized. And, in fact, the heritability estimates are not the 80-85 percent that some researchers claimed, but instead are far less. A new review article published in Psychiatry Research (Torrey & Yolken, 2019) reminds us how high initial hopes were for genetics to help explain the cause of schizophrenia: […By] the end of the 20th century genetic theories had become predominant. It was said that schizophrenia “is an undoubtedly genetic disorder” with “heritability estimates of approximately 80%–85%” (Pearlson and Folley, 2008, Cardno and Gottesman, 2000). Some geneticists even suggested “a strong possibility that most or all of the remaining small proportion of variance can be explained by non-transmissible changes in gene structure or expression” (McGuffin et al., 1994). In other words, schizophrenia might be 100% genetic with environmental factors playing little or no role. Since that time, researchers have found nothing like what they expected: According to one recent analysis, “the current trend in psychiatric...
Source: World of Psychology - Category: Psychiatry & Psychology Authors: Tags: General Research Schizophrenia Causes Of Schizophrenia Schizophrenia Causes Source Type: blogs