New research reveals that autism, ADHD, schizophrenia, bipolar disorder, depression, Tourette’s syndrome, OCD, and anorexia share a common genetic foundation, suggesting that treatments targeting these shared factors could potentially address multiple conditions at once. The study, published in Cell, identifies 683 genetic variants that impact brain development and gene regulation across these disorders.
Common Genetic Roots: The Role of Pleiotropy
For years, scientists have observed that these eight psychiatric conditions frequently co-occur—up to 70% of individuals with autism or ADHD are also diagnosed with the other. This new research provides a genetic explanation: pleiotropic variants. These are genetic changes that influence multiple, seemingly unrelated traits.
In this case, pleiotropic variants in shared genes were found to be more extensively connected to other proteins and active across a wider range of brain cells than those unique to specific disorders. This means that changes in these genes can have ripple effects throughout the brain, potentially contributing to diverse conditions.
How the Research Was Conducted
The team at the University of North Carolina analyzed nearly 18,000 genetic variations, both shared and unique to the eight conditions. They inserted these variations into precursor cells that become neurons, observing how they impacted gene expression during development. Further testing in developing mice confirmed the effects of these genetic variants.
“The proteins produced by these genes are highly connected,” explains geneticist Hyejung Won. “Changes to these proteins could ripple through the network, causing widespread effects on the brain.”
Implications for Treatment
This discovery shifts the understanding of psychiatric disorders from distinct categories to overlapping genetic pathways. Historically, pleiotropy has complicated classification. However, Won argues that understanding the genetic basis of pleiotropy could unlock new therapeutic strategies :
If researchers can identify and target these shared genetic factors, it might be possible to develop a single therapy that treats multiple conditions simultaneously. Given that the World Health Organization estimates nearly one billion people worldwide live with some form of psychiatric condition, this approach could be profoundly beneficial.
The findings underscore that the line between these conditions may be blurrier than previously thought, offering a fresh direction for future research and treatment development.
