Figure 1. Shared genetic risk across 14 psychiatric disorders.
This diagram illustrates the five major genetic factors identified in the study: Compulsive Disorders, Schizophrenia-Bipolar Disorders, Neurodevelopmental Disorders, Internalising Disorders, and Substance Use Disorders. Each cluster groups psychiatric disorders that share significant genetic risk, highlighting the biological connections between conditions and explaining why individuals often have multiple diagnoses./Credits Nature
Psychiatric disorders have traditionally been viewed as separate conditions. But a recent study shows that many of them share common genetic risks, meaning they are biologically connected, which could help develop treatments targeting multiple disorders at once which could improve outcomes for patients worldwide.
A substantial genetic study published in the journal Nature finds that many psychiatric disorders have similar biological risk factors. The researchers analysed DNA samples from more than 1,056,000 individuals affected by one or more of 14 different psychiatric disorders.
The results indicate that the majority of inherited risk for psychiatric disorders can be grouped into five major biological risk factors instead of being unique to each disorder. For example, a group of compulsive disorders that includes anorexia nervosa, obsessive-compulsive disorder, and Tourette’s disorder (a motor tic) formed one of the five genetic risk factors for psychiatric disorders.
Schizophrenia and bipolar disorder were another clustering of psychiatric diseases under one of the genetic risk factors identified.
Neurodevelopmental disorders that include autism spectrum disorder and attention-deficit hyperactivity disorder (ADHD) cluster together and are identified under another biological risk factor.
All internalising disorders, including major depression, anxiety disorders, and post-traumatic stress disorder (PTSD) are combined under the fourth biological risk factor.
Finally, substance use disorders that include alcohol, nicotine, opioids, and cannabis dependence are derived from the fifth shared biological risk factor.
The researchers also identified a specific number of areas on human chromosomes that demonstrated an impact on multiple disorders, specifically 238 genetically related chromosome regions. These regions are believed to relate to gene activity in the brain, as there were hotspots located on chromosome 11 associated with multiple disorders.
Furthermore, it has been suggested that the biological overlap of risk involved with multiple disorders explains why many individuals receive multiple psychiatric diagnoses. According to Dr Jordan W. Smoller, an associate professor in the Department of Psychiatry at Harvard Medical School and co-author of the study, "The study provides a clearer roadmap for understanding genetic overlap between psychiatric disorders."
The majority of individuals in this study, however, were of European descent, and thus the findings may not reflect all populations. Still, the findings in this study can serve to assist in providing a clearer understanding of the biological basis for diagnosis and developing more effective treatment options targeting the shared biological risk across psychiatric disorders.
Additionally, the researchers suggest that health care delivery systems should consider shared risk factors associated with all mental health disorders.
Reference
Grotzinger, A. D., Werme, J., Peyrot, W. J., et al. (2025). Mapping the genetic landscape across 14 psychiatric disorders. Nature. https://doi.org/10.1038/s41586-025-09820-3
