Differences in gene expression among immature white blood cells from people with panic disorder and healthy peers may be the basis for a future test to help diagnose the disorder, according to an article published online March 6 by the American Journal of Medical Genetics.

"The ability to test for panic disorder is a quantum leap in psychiatry," said the study's lead author, Robert Philibert, MD, PhD, professor of psychiatry in the University of Iowa’s Roy J. and Lucille A. Carver College of Medicine.

"Panic disorder will no longer be a purely descriptive diagnosis, but, as with cystic fibrosis, Down Syndrome and other conditions, a diagnosis based on genetic information," he said. "In addition, the finding could help us better understand the pathways that initiate, promote and maintain panic disorder."

The team compared gene expression in lymphoblasts obtained from 16 participants with panic disorder and 17 participants without the disorder. The study found many genes were more expressed in people with panic disorder than in people without the condition. Similarly, the study found many genes were less expressed in people with panic disorder. There were also sex-related differences.

Overall, people with panic disorder had noticeably different patterns of gene expression than people without the disorder. Approximately 3 percent of people in the United States have panic disorder, which involves having at least one panic attack every four weeks.

"People with panic disorder often end up in the emergency room for heart tests when in fact they have panic disorder. This is just one of the reasons that it would be helpful to have a blood test for panic disorder," Philibert said.

He added, "We certainly intend for this finding to help people manage their disease, and when possible, to prevent it from affecting their lives. If we can, it could help us identify systems that interact with the environment and possibly lead the way to new, even non-drug, therapies to prevent illness."