Researchers have found that eight different mental illnesses share a common genetic basis.

Research published in early 2025 identified specific variants of these shared genes and showed how they behave during brain development.

The US team found that many of these variants remain active for long periods of time and can affect multiple developmental stages, providing new therapeutic targets that can address multiple diseases at once.

Related: Research tracing the origins of autism to improvements in human intelligence

“The proteins produced by these genes are also highly related to other proteins.” explained Hye-Jung Wong, a geneticist at the University of North Carolina.

“Changes to these proteins in particular can ripple through networks and cause widespread effects in the brain.”

Going back to 2019, international team for the first time identified 109 genes associated in various combinations with eight psychiatric disorders. autism, ADHD, schizophreniabipolar disorder, major depressive disorder, Tourette syndrome, obsessive-compulsive disorder, anorexia.

This may explain why these conditions often occur together. for example, up to 70 percent A large percentage of people diagnosed with autism or ADHD also have other autism conditions. Explains why they are often concentrated within families.

Each of these eight diseases also has unique genetic differences, so Wong and his team compared their unique genes to the genes shared between the diseases.

They took nearly 18,000 variations of related common and unique genes and put them into progenitor cells We will examine what becomes our neurons and how gene expression in these cells is affected during human development.

This allowed the researchers to identify 683 genetic mutations that affect gene regulation and investigate them further in developing mouse neurons.

The genetic variation behind multiple seemingly unrelated traits, or in this case a condition, is called a. pleiotropy. Pleiotropic variants were involved in more protein-protein interactions and were active across more types of brain cells than gene variants specific to a particular psychological state.

Pleiotropic mutants were also involved in regulatory mechanisms affecting multiple stages of brain development. The ability of these genes to influence cascades and networks of processes such as gene regulation may explain why the same variants contribute to different conditions.

“Pleiotropy has traditionally been considered a challenge because it complicates the classification of mental disorders.” said I won.

“However, if we can understand the genetic basis of pleiotropy, we may be able to develop treatments that target these common genetic factors, thereby potentially treating multiple psychiatric disorders with common therapies.”

This can be a very useful strategy considering the following situations: world health organization It is estimated that one in eight people (almost 1 billion people in total) lives with some form of an infectious disease. mental state.

This study cell.

A previous version of this article was first published in February 2025.