Psychiatric disorders share genetic links, according to a new study of the genomes of more than 1 million people by the Brainstorm Consortium, which includes researchers from the University of Washington Schools of Public Health and Medicine.
The study, released last Thursday in the journal Science, examined whether 25 common neurological and psychiatric brain disorders share similar gene variations that could indicate risk factors for these disorders.
Researchers found common variant genetic risk among people with psychiatric disorders, especially those with attention deficit hyperactivity disorder (ADHD), bipolar disorder, anxiety disorder, major depressive disorder (MDD), and schizophrenia. Neurological disorders, such as Alzheimer’s disease, epilepsy, and Parkinson’s disease, each had very distinct variant genetic risk and had no commonalities with psychiatric disorders, with one exception. Migraines had a strong correlation to ADHD, MDD, and Tourette syndrome.
“This is a groundbreaking collaborative study, both in size and content,” said co-author Walter Kukull, professor of epidemiology and director of the National Alzheimer’s Coordinating Center at the University of Washington. "Genomic associations with neurological and psychiatric diseases has never been shown on this level.”
Researchers also examined genetic links between brain disorders and observable characteristic traits, or phenotypes, such as cognitive performance, years of education, body mass index (BMI), personality and smoking habits. They found that in a general population, neuroticism was associated with almost every psychiatric disorder and migraine. Cognitive performance in early life was also linked to genetic risk of having a neurological or psychiatric disorder later in life.
The findings from this study add to the growing evidence that the clinical diagnostics for psychiatric disorders don’t reflect the cause or origin of the disease. Kukull and his colleagues say more research is needed, but this paves the way toward the development of improved methods of diagnosis and specialized treatment for psychiatric disorders.
The Brainstorm Consortium is a collaboration among more than 600 international researchers led by the Broad Institute of MIT and Harvard. Contributing researchers from the University of Washington include Eric B. Larson, Joshua A. Sonnen (now at the University of Utah), Joshua C. Bis, and Ellen Wijsman and Kenneth Rice.