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March 10, 2020

Study finds Middle Eastern war refugees show biomarkers for PTSD

A newly-published study led by a Michigan State University professor has identified two biomarkers in recent Middle Eastern war refugees that appear to be related to post-traumatic stress disorder and other mental health problems.

The researchers found elevated levels of two brain chemicals – neurotrophic growth factor and nerve growth factor – in the blood of refugees who recently had arrived in Michigan from Iraq and Syria and exhibited symptoms of PTSD, depression and anxiety. Those chemicals, known collectively as neurotrophins, are involved in the brain’s ability to form new connections between neurons in response to brain injuries, a process called neuroplasticity.

“In effect, the neurotrophins created a dysfunctional rewiring of the brain that makes the refugees relive these experiences,” said Bengt Arnetz, the study’s principal investigator and chair of the College of Human Medicine Department of Family Medicine. “That was a new finding.”

The study appears in the current issue of the scientific journal PLOS ONE.

The researchers also examined whether those refugees who reported they had been exposed to environmental contaminants, such as lead and other heavy metals, had higher levels of the two neurotrophins in their blood. 

Arnetz said that the men and women from Syria also were more likely to report they had been exposed to environmental contaminants in fact, many of them had high levels of manganese in their bodies. 

“There is a definite association between higher environmental exposure and PTSD,” Arnetz said.

Those refugees with large amounts of lead in the blood also had elevated levels of the two neurotrophins and scored higher on a PTSD index, the study found. 

Further research is needed to understand how the psychological trauma of war and environmental exposure contribute to adverse mental health, the authors suggested.

Other researchers from Michigan State University and Wayne State University assisted in the study. The full text of the study can be found at


By: Bengt Arnetz

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