they anticipated exposure to chemical warfare; the risk increased with time spent in the field and exposure to the dead and wounded. Another stressor was the feeling that they were deserting their families at a time of need.

In OEF and OIF, many of the stressors are more reminiscent of the Vietnam War than of the 1991 Gulf War or World War II. With the defeat of the Iraqi Army and later sectarian violence, U.S. troops have been subjected to guerilla warfare and terrorist actions from civilian insurgents and militias, particularly the use of improvised explosive devices. Soldiers must be constantly on guard, and all civilians must be viewed with caution. Department of Defense (DoD) surveys of Army soldiers and Marines stationed in Iraq found that exposure to combat was the critical determinant of a soldier’s or Marine’s mental health.


A person exposed to a stressor, deployment-related or not, may experience a stress response. The word stress is used in many contexts and has a variety of meanings. It is often used to describe a situation characterized by real or perceived threats, but it is also commonly used to refer to the body’s response to such threats. Thus, stress has been used both to describe the environmental events (the stressors) that trigger responses and to refer to the resulting changes (stress response) that occur in the brain and the rest of the body.

The stress response is a coordinated set of interactions among multiple organ systems in the body, including the brain, gut, heart, liver, immune system, thyroid, adrenals, pituitary, gonads, bone, and skin. In response to a stressor, the body initiates an acute stress response. Acute stress responses are usually adaptive, preparing the body for “fight or flight.” After exposure to the stressor has ended, the acute stress response subsides, and the body returns to its normal state. However, if the body’s reactions persist after the stressor has ended, a chronic stress response can develop, which can be maladaptive and result in feelings of anxiety and lack of control and chronic health effects. Stressors can also lead to adverse psychosocial effects—such as marital conflicts and homelessness—concurrently with or after the development of health effects. Whether the stress response leads to adverse health effects either in the short term (hours to days) or in the long term (months to years) is determined by a number of factors, including the intensity and duration of the stressful experience, the effects of previous stressors, and risk factors (such as genetic susceptibility or a history of a psychiatric disorder) and protective factors (such as military training or supportive family and social environment). Thus, each person’s response to stress can be modified on the basis of the specific deployment-related stressors, the complex nature of the stress response, and risk and protective factors.


It is widely recognized that soldiers can suffer psychologic consequences during and after combat. After the Vietnam War, research demonstrated that many veterans, particularly those exposed to severe war-related trauma, and such other traumatized populations as Holocaust survivors, suffered from chronic psychologic problems that often resulted in social and occupational dysfunction. The constellation of symptoms that has come to be known as PTSD is an anxiety disorder whose occurrence is precipitated by exposure to a traumatic event. PTSD

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