Recent research from Naval Health Research Center's (NHRC) Warfighter Performance Department found physical activity may diminish the risk of major depressive disorder (MDD) and suicidal ideation (SI) in individuals with a genetic predisposition.

Study findings were published online in the January issue of "Psychiatry Research."

The NHRC study, "A genetic risk factor for major depression and suicidal ideation is mitigated by physical activity," cited past research which identified MDD as the most common psychiatric disorder and SI as the strongest risk factor for attempted and completed suicide. Despite this, NHRC researchers stated little is known about their causes, particularly in vulnerable populations, such as service members who are exposed to chronic stress and combat.

Previous research has found physical activity or exercise and genetic factors may influence behavioral health, but less is known about how they work together, according to study authors. In the current study, NHRC researchers sought to determine if physical activity can reduce the genetic risk for mood disorders.

Researchers evaluated more than 700 active-duty, volunteer participants. Data collection included DNA from saliva samples and self-report survey responses which assessed depression, perceived stress, and physical activity.

According to study authors, research findings demonstrate some military members have a higher genetic risk of depression and suicidal thoughts, but engaging in physical activity at levels which meet national recommendations -- 30 minutes of moderate-intensity activity five days per week or 20 minutes of vigorous-intensity activity three days per week -- may protect against some of these risks.

Additionally, researchers found:

* Individuals with the genetic risk factor were twice as likely to report MDD and SI than those without the genetic risk factor.
* Individuals who did not meet physical activity guidelines were twice as likely to report MDD and SI than participants who met recommendations for physical activity.
* Individuals who did not meet guidelines for physical activity and had the genetic risk factor for MDD and SI were more than twice as likely to develop mood disorders than participants who did not have the genetic risk factor and did meet the recommended physical activity.

Study authors suggest lifestyle modifications which include getting the recommended amount and intensity of physical activity may effectively target mood disorders in genetically vulnerable individuals.

Future research directions may include evaluating the effectiveness of promoting physical activity in genetically vulnerable populations for improving overall health outcomes.

The Warfighter Performance Department:

Marc Taylor leads the Biobehavioral Sciences Lab in the Warfighter Performance Department NHRC. The team investigates the associations between physical and psychological stressors and factors which can mitigate their negative impact on the warfighter. Their research expertise includes stress physiology, salivary bioscience, and human performance in extreme environments.

The Publication:

http://www.ncbi.nlm.nih.gov/pubmed/28142104

About NHRC:

As the Department of Defense's premier deployment health research center, NHRC's cutting-edge research and development is used to optimize the operational health and readiness of the nation's armed forces. In proximity to more than 95,000 active-duty service members, world-class universities, and industry partners, NHRC sets the standard in joint ventures, innovation, and translational research.

For more information, visit http://www.navy.mil, http://www.facebook.com/usnavy, or http://www.twitter.com/usnavy.

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