Throughout history war has always resulted in a significant psychological cost to the men (and now women) who are members of the military. The Iraq war is no different. A fairly balanced article in the LA Times looks at some of the psychiatric problems being seen in Iraqi veterans:
A study by the Walter Reed Army Institute of Research found that 15.6% of Marines and 17.1% of soldiers surveyed after they returned from Iraq suffered major depression, generalized anxiety or post-traumatic stress disorder — a debilitating, sometimes lifelong change in the brain's chemistry that can include flashbacks, sleep disorders, panic attacks, violent outbursts, acute anxiety and emotional numbness....
When you think of psychiatric disorders along a spectrum from "biological" to "psychosocial", there are some people who are biologically resiliant and not subject to psychiatric illness under most "normally" stressful situations. But war is not "normally" stressful. It is stressful like no other situation for a living being. And that is why even the biologically resiliant can develop problems; not to mention those who might be more physiologically prone to depression or anxiety or psychosis.
Combat stress disorders — named and renamed but strikingly alike — have ruined lives following every war in history. Homer's Achilles may have suffered from some form of it. Combat stress was documented in the late 19th century after the Franco-Prussian War. After the Civil War, doctors called the condition "nostalgia," or "soldiers heart." In World War I, soldiers were said to suffer shell shock; in World War II and Korea, combat fatigue or battle fatigue.But it wasn't until 1985 that the American Psychiatric Assn. finally gave a name to the condition that had sent tens of thousands of Vietnam veterans into lives of homelessness, crime or despair.
After WWI, the military got the idea of placing psychiatrists and mental health professionals near to the front line to deal immediately with some of these stress disorders. It seemed to work better and prevent some of the longer-term problems. After the immediate intervention, they were either returned to the front, or sent back for longer treatment. You might remember the 1963 movie "Captain Newman, M.D.", starring Gregory Peck, which was about a military psychiatrist who ran a mental ward during WWII.
During the Korean War, the M.A.S.H. units and military facilities near the front also had psychiatrists attached to them. Nowadays, of course, the pharmacological and psychotherapeutic interventions are considerably better than they were in the middle of last century. The faster one can intervene with those soldiers at risk, the better--before they can injure themselves or others. Reportedly there have been about 30 suicides by soldiers in Iraq, and this is an indication that there is not sufficient mental health support at the front lines; especially since even one suicide is too many.
Vietnam gave us the term "Post-Traumatic Stress Disorder" (PTSD), which was originally used to describe the stress syndrome noted in its veterans when they returned home (but which described symptoms that every veteran of every war in history was likely aware of). It was estimated that maybe 30% of Vietnam vets had some symptoms of this disorder, which is now well-described in the literature and also applicable to people in traumatic situations other than war. I have always suspected that PTSD was probably more common in wars like Vietnam, where many of the soldiers were not there voluntarily (due to the military draft); but whether one volunteers or is drafted, there is no doubt that war is hell, and that it dramatically, intensely, and sometimes irrevocably impacts body, mind, and soul.