Schizophrenia is a chronic, severe, and disabling psychiatric disorder that affects approximately two million Americans in any given year. Despite extensive research, the causes of schizophrenia are still unclear. “There is no single organic defect or infectious agent which causes schizophrenia, but a variety of factors increase the illness—among them genetics and obstetric complications,” wrote the late Colorado Recovery founder Richard Warner, MD, in his influential book The Environment of Schizophrenia. “Relatives of people with schizophrenia have a greater risk of developing the illness, the risk being progressively higher among those who are more genetically similar to the person with schizophrenia.” 

Genetics is only part of the story, though. “Since the identical twin of a person with schizophrenia only has a 50 percent risk of developing the illness, we know that genetics alone do not explain why someone gets the illness,” wrote Dr. Warner. “Other powerful factors have to play a part; one of these factors is problems of pregnancy and delivery. The risk for people born with obstetric complications, such as prolonged labor, is double the risk for those born with none.” 

But which genes exactly are responsible for the increased risk? Most scientists have always assumed that genes linked to schizophrenia were primarily, if not entirely, related to the brain. 

An interesting new study conducted by the Lieber Institute for Brain Development suggests that the risk of schizophrenia is primarily due to the role of over 100 associated genes in the placenta, rather than in the developing brain. The research by Ursini, Weinberger, et al., published in Nature Communications, highlights a more substantial involvement of the placenta in the origin of the illness than previously recognized.

“The secret of the genetics of schizophrenia has been hiding in plain sight—the placenta, the critical organ in supporting prenatal development, launches the developmental trajectory of risk,” said Daniel Weinberger, MD, senior author of the paper and director and CEO of the Lieber Institute for Brain Development in Baltimore. “The commonly shared view on the causes of schizophrenia is that genetic and environmental risk factors play a role directly and only in the brain, but these latest results show that placenta health is also critical.”

The researchers found that “schizophrenia genes influence a critical function of the placenta to sense nutrients in the mother’s bloodstream, including oxygen, and exchange nutrients based on what it finds,” explains an article in SciTechDaily. “The schizophrenia risk genes are more lowly expressed in the cells of the placenta that form the core of this maternal-fetal nutrient exchange, called trophoblasts, negatively affecting the placenta’s role in nurturing the developing fetus.”

The study also identifies several genes in the placenta that are causative factors for diabetes, bipolar disorder, depression, autism, and attention deficit hyperactivity disorder (ADHD). However, the researchers found far more genetic associations with genes for schizophrenia than for any of these other disorders.

The researchers also discovered that the risk genes for schizophrenia found in the placenta may have a relatively greater effect on heritability, the likelihood of illness inherited from ancestors, than risk genes found in the brain.

“Targeting placenta biology is a crucial new potential approach to prevention, which is the holy grail of public health,” said lead author Gianluca Ursini. “Scientists could detect changes in placental risk genes decades before the possible onset of a disorder, possibly even in the mother’s bloodstream during pregnancy. If doctors knew which children were most at risk of developmental disorders, they could implement early interventions to keep them healthy.”

The scientists also found interesting sex-based differences in the placenta risk genes. Different genes were associated with schizophrenia risk based on whether the placenta came from a male or female child. In pregnancies with male children, inflammatory processes in the placenta seem to play a central role. Previous research has shown males are more vulnerable than females to prenatal stress. Generally speaking, developmental disorders such as schizophrenia occur more frequently in men and boys.

The Lieber Institute researchers hope their ongoing study of the genes of the placenta will one day lead to new treatment and diagnostic tools, perhaps revolutionizing the field of prenatal medicine.

Recovery from a serious mental illness such as schizophrenia requires that people experiencing the disorder retain a sense of empowerment—a belief in their ability to take charge of their lives and manage the complex demands and consequences of the illness.

Colorado Recovery has been utilizing the Warner method to empower adults with mental illness for many years now. Our program approaches mental healthcare based on a path of self-reliance through developed practiced skills. Recognizing the importance of empowerment for recovery, our non-institutionalized philosophy offers comprehensive levels of care supported by an expert medical and clinical team, engaging patients in increasing community participation. 

Our treatment facility provides the services needed to address schizophrenia, bipolar disorder, and other serious mental illnesses. Call us at 720-218-4068 to discuss treatment options for you or the person you would like to help.