Researchers have uncovered new genetic evidence linked to anxiety in the largest study on the condition that included about 200,000 veterans.
By comparing the participants’ genomes, the researchers pinpointed six genetic regions related to anxiety and their ties with other psychiatric conditions.
Dr. Joel Gelernter, a senior co-author of the study, said the research provides molecular evidence of shared genetic risk for anxiety and other psychiatric conditions such as depression, which can help identify specific genes that affect risks for such disorders.
“To the extent that it identifies genes that were not previously known to be associated biologically with these traits, it will help us understand the biology, and biology can lead to treatment strategies,” said Dr. Gelernter, who is a Yale University professor and psychiatrist for the VA Connecticut Healthcare Center. “So the ultimate hope is that this study and/or its successor studies will begin to lead us to understand novel biology, which can then lead us to novel treatments that are relevant to anxiety traits.”
The study, published last week in the American Journal of Psychiatry, pulled data from the Million Veteran Program, one of the world’s largest biodata banks that includes genetic and medical information from U.S. military veterans.
About 40 million adults in the U.S., or 18%, live with anxiety disorders — the most common mental illness, according to the Anxiety and Depression Disorder of America.
However, the study’s researchers estimate that anxiety disorders affect 1 in 10 Americans each year.
Dr. *Elspeth Ritchie, a retired military psychiatrist and chief of psychiatry at MedStar Washington Hospital Center, said the differences in numbers could be due to how anxiety is defined, commenting on how post-traumatic stress disorder used to be medically categorized as an anxiety disorder.
It is estimated that only about a third of those with anxiety disorders receive treatment.
“Although there are not immediate treatment implications for our findings, they do point us toward future treatments that may involve some of the biochemical pathways and systems identified by our research,” said Dr. Murray Stein, a co-author of the study, University of California San Diego professor and staff psychiatrist for the VA San Diego Healthcare System.
He said genome-wide association studies, such as this one, examine millions of markers across the entire genome to see if each marker is more or less common among people with anxiety.
The research team found five genetic variants related to anxiety in European Americans and one in African Americans.
While previous similar studies examined traits among individuals of mostly European descent, this study also included DNA samples from African Americans, who are not always included in large genetic studies, said Dr. Gelernter.
The study discovered the first genome-wide significant findings on anxiety in African ancestry, according to a press release by the Department of Veterans Affairs.
About 18% of the enrollees in the Military Veteran Program, which has more than 800,000 participants, are African American.
One of the variants linked to anxiety the researchers identified occurs in an estrogen receptor. Women are more likely to have anxiety and depression traits, said Dr. Gelernter, but this variant was found in a primarily male study group. He said he would like to eventually test sex differences of this genetic variant.
People with anxiety disorders often experience intense, disproportionate concerns about anticipated events that lead to distress that can interfere with daily activities.
“Anxiety is very common, and it’s also very common for it to be either untreated and undertreated. We do have decent treatments for it,” said Dr. Ritchie. “I think it’s important [to treat] because anxiety really gets in people’s way.”
She noted there hasn’t been much progress so far in the development of new psychiatric treatments based on genetic studies.
Some medications and types of psychotherapies such as cognitive behavioral therapy effectively treat anxiety disorders.
Genetic studies in other fields of medicine have led to precision medicine approaches for treating various diseases. The study’s researchers hope more genetic insight into anxiety will lead to the development of tailored treatments for psychiatric patients.
The research team also found that genetic variants tied to anxiety overlapped with other psychiatric conditions such as neuroticism, schizophrenia and insomnia.
(* Correction: An earlier version of the story incorrectly stated Dr. Elspeth Ritchie’s name. The story has been updated.)