Unknown risk factors for schizophrenia, ADHD and autism have been discovered

How high-risk pregnancies affect neurodevelopmental disorders

A recent study reports on the role of the maternal placenta as a hitherto unknown link between the genes and the development of possible neurological developmental disorders such as schizophrenia, ADHD, autism, dyslexia and Tourette syndrome. According to the researchers involved in the study, there is a strong correlation between pregnancy complications, certain genetic preconditions and the development of mental illness. This relationship is apparently controlled by the placenta.

Based on the research results, it will be possible in the future to predict more precisely who is threatened by mental illness. In addition, the work allows new therapeutic approaches to reduce mental illness or even prevent it. The previously completely neglected placenta plays a key role here. The study was conducted by researchers from the Institute for Brain Development (LIBD) in Baltimore and recently published in the journal Nature Medicine.

A new study shows the relationship between placenta, certain genetic conditions and pregnancy complications. This combination increases the risk of neurodevelopmental disorders enormously. (Image: unlimit3d / fotolia.com)

The placenta has always been a high priority in mythology

In ancient customs and also in many primitive peoples, the placenta is said to have a healing or fortune-producing effect. For example, in the form of powder or essence, it has been processed into remedies or buried in the garden and a tree planted thereon. Homeopathy also uses the placenta as a remedy. From a scientific point of view, the pie has so far played a minor role, but recent research could change that.

Early complications in pregnancy

"For the first time, we found an explanation for the relationship between early complications, genetic risk and their impact on mental illness," LIBD Chief Daniel R. Weinberger said in a press release on the study's findings. It revealed that the placenta makes a key contribution to this development. Previous studies on this topic have only considered certain genetic preconditions as a risk to mental illness.

What role does the placenta play??

The placenta supplies the embryo with nutrients and chemicals that are critical for normal prenatal development. The scientists found that many genes associated with the risk of schizophrenia appear to indirectly alter early brain development by affecting the placenta. For pregnancy complications, these genes become active.

Schizophrenia and the womb

For more than 25 years, researchers have assumed that the risk of a neurodevelopmental disorder such as schizophrenia already develops during pregnancy and shortly after birth. So far, scientists have assumed that only the genetic variants are responsible for this development. However, the biological mechanisms were poorly understood. The latest study shows that the combination of pregnancy complications and certain genetic variants increases the risk of certain neurodevelopmental disorders by at least five times.

Course of the study

The researchers in Baltimore examined more than 2,800 adults, of whom 2,038 had schizophrenia. Subjects were of various ethnic origins and came from different continents, including North America, Europe and Asia. All were genetically examined. Furthermore, the birth history of the participants was considered. The researchers found a strong interaction between pregnancy complication and genes associated with schizophrenia risk.

Pregnancy complications and genetic preconditions

The researchers showed that people with a high genetic risk who had severe complications during pregnancy were at least five times more likely to develop schizophrenia than those with a similarly high genetic risk, but none Pregnancy complications occurred. In experiments, the scientists found that during the complications, the genes responsible for schizophrenia are active and as a result, the placenta is under increased stress and, for example, more inflammatory reactions.

Placenta as the new heart of research

Permanent stress of the mother affects the baby via the amniotic fluid. This was already demonstrated by a Zurich research group in 2017. "The surprising results of this study make the placenta the centerpiece of a new area of ​​biological research related to the interaction of genes and the environment," concludes Weinberger. Future studies will now test new approaches to therapeutic treatments and prevention strategies in which the placenta plays a central role. (Vb)