New study shows 14 psychiatric disorders share genetic roots
An international team of scientists has produced the most comprehensive picture to date of how genetic factors contribute—both jointly and uniquely—to a broad range of mental health conditions.
In a landmark analysis including over 1 million people diagnosed with psychiatric disorders and 5 million controls, researchers from the Psychiatric Genomics Consortium (PGC) report that most genetic influences on mental illness are shared across diagnostic categories, revealing a more interconnected biological landscape than traditional classifications suggest.
The study analyzed genome-wide data for 14 childhood- and adult-onset psychiatric disorders. Using multiple cutting-edge genomic methods, the researchers examined how genetic risk is distributed across disorders and what biological underpinnings are implicated.
“The study shows that most of the inherited risk across the 14 disorders can be explained by five underlying “genomic factors,” representing five groups of psychiatric diagnoses explains Professor Anders Børglum from the Department of Biomedicine at Aarhus University and one of the international researchers who has contributed to the study. “Genetic risk is shared extensively across all 14 disorders, but some are genetically more closely related than others and cluster into five groups.”
Spans from schizophrenia to substance use disorders
The five groups of genetically closely related psychiatric disorders (“genomic factors”) that are characterized in the study are:
- Compulsive Disorders (OCD, anorexia nervosa, Tourette syndrome)
- Schizophrenia–Bipolar Disorders
- Neurodevelopmental Disorders (ADHD, autism)
- Internalizing Disorders (depression, anxiety, PTSD)
- Substance Use Disorders (alcohol, opioid, nicotine, cannabis)
“In total the study uncovers 238 genetic variants that contribute to cross-disorder risk across the five groups” says Professor Ditte Demontis from the Department of Biomedicine at Aarhus University who is also co-author of the paper.
Underlying biology and therapeutic perspectives
By integrating the genetic findings with data from developing and adult human brain tissue, the study points to specific biological processes and cell types implicated across disorders.
The broadly shared genetic risk across all disorders was linked to fundamental biological processes involved in regulating gene expression—particularly active during early brain development.
“Other remarkable findings are that the Schizophrenia–Bipolar group was strongly associated with genes active in excitatory neurons, especially in the hippocampus, while the Internalizing factor (depression, anxiety, PTSD) showed enrichment in genes active in oligodendrocytes, cells involved in brain connectivity, explains Ditte Demontis.
The findings provide one of the clearest indications yet that psychiatric disorders share substantial genetic foundations that cut across current diagnostic boundaries. They also offer new entry points for developing treatments that target risk pathways common to frequently co-occurring conditions.
“This study brings us closer to a biologically informed map of mental illness,” says Anders Børglum “and highlights biologic pathways that could guide future research of the biologic mechanisms, prevention, and development of therapeutics that may be effective across groups of psychiatric diagnoses.”
About the study
- Studytype: GWAS (genome-wide association study) involving the investigation of all (millions of) commonly occurring genetic variants across the entire genome in individuals from several large cohorts (here approximately 6 million people). A range of advanced statistical genetic methods are used to identify the genes involved, characterise the genetic architecture, and determine the affected biological processes.
- Research partners: The international “Psychiatric Genomics Consortium”.
- Funding: The Lundbeck Foundation, NIMH, and EU grants.
- Read more in the scientific article: https://www.nature.com/articles/s41586-025-09820-3
Contact:
Professor Anders Børglum
Department of Biomedicine, Health, Aarhus University
Mail: anders@biomed.au.dk
Phone: +4560202720
Professor Ditte Demontis
Department of Biomedicine, Health, Aarhus University
Mail: ditte@biomed.au.dk
Phone: +4528539746