Physical injuries to the brain can now be detected with more precise instruments like MRI and can often be treated. In the last six years it has become clear that there are several sources of PTSD (post-traumatic stress disorder) and concussions from explosions were more of a factor than previously thought. Many troops, because of exposure to roadside bombs and battlefield explosions in general, developed minor concussions that, like sports injuries, could turn into long term medical problems. Often these concussions were accompanied by some PTSD. Examining medical histories of World War II, Korea, and Vietnam War vets showed a pattern of later medical problems among many concussion victims. The same pattern has been found among athletes and accident victims who suffered concussions. Medical experts concluded that pulling troops out of combat after being exposed to three explosions would have long term benefits, in that it would prevent most permanent brain injuries and PTSD, including cases that could require a soldier or marine to be retired early on medical disability.
Combat commanders, and many of the troops pulled out of combat this way, were opposed to the policy. Commanders felt that sending units into action with fewer troops made it more likely that they will suffer still more casualties. Infantrymen tend to be reluctant to leave their buddies in the lurch, unless physically unable to continue fighting. The military sought to convince troops that, like boxers, hockey, or football players, too many concussions will lead to serious problems down the line or even sooner.
Another problem with this proposal is that roadside bombs are only one of several sources of concussions. But the military medicine experts believe that roadside bombs were by far the biggest source of these concussions and the resulting brain injuries. The "three bombs and you're out" (of combat) rule tended to not pull more than one or two percent of troops out of action. But this had a higher impact on combat units, which always suffer most of the casualties. Thus infantry units can lose another 5-10 percent of their troops.
The U.S. Army has been conducting a long-term study to identify and measure the impact of combat zone stress and concussions on soldiers. This began with a random selection of 55,000 soldiers, who were interviewed to obtain additional data on their experiences in the military. That will be periodically updated for the lives of the study subjects. Over the decades the army will learn more and more about military and combat stress and be better able to develop policies to avoid it and create treatments for harmful aftereffects.
This is one of a growing number of efforts to deal with an unprecedented number of troops who have spent a lot (more than any other war) of time in a combat zone. The result of this is that over the last decade more and more combat NCOs and junior officers have been found to be suffering from debilitating PTSD. Studies so far have found that at least 20 percent of troops sent into a combat zone suffer some form of mental distress. That's over 400,000 troops (out of two million who have served in Iraq or Afghanistan). Not all these are actually diagnosed, often because the victim is unaware that they have PTSD. Taking the recent victims and adding in the many Vietnam veterans who have been treated for PTSD and studied, the army has already found some useful data. For example, troops are more prone to serious PTSD effects (including suicide) if there are genetic factors (often, but not always, revealed by a family history of psychiatric problems), traumatic childhood events, and insufficient support and treatment after traumatic battlefield events. For centuries it's been accepted that some men are prone to "break" under the stress of combat. It was understood, even without any knowledge of genetics, that a soldier with a family history of mental instability would be less able to handle combat. Now the army can more precisely measure the risk and more accurately screen out those who will be most at risk.
The major problem is that most people eventually get PTSD if they are in combat long enough. This has been confirmed by nearly a century of energetic efforts to diagnose and treat PTSD (including much more recent attention to civilian victims, via accidents or criminal assault). During World War II it was found that, on average, 200 days of combat would bring on a case of PTSD. After World War II methods were found to delay the onset of PTSD (more breaks from combat, better living conditions in the combat zone, prompt treatment when PTSD was detected). Military historians note that successful, and often popular, commanders throughout history have paid attention to the physical well-being of the troops, all in the name of "maintaining morale." These measures also delayed the onset of combat fatigue.
That's why combat troops in Iraq and Afghanistan often slept in air conditioned quarters, had Internet access, lots of amenities, and a two week vacation (anywhere) in the middle of their combat tour. This extended their useful time in combat before PTSD (or "bad morale") sets in. No one is yet sure what the new combat days average is, and the new screening methods are an attempt to find out. The army and marines are now confronting the fact that, for a large number of their combat NCOs, the limits are being reached. It's a lot more than 200 days in combat but the army and marines have the majority of their most able and experienced NCOs approaching that limit.
This was not unexpected. The army knew that they had a large, and growing, percentage of its combat troops with over 200 days of combat. Some have three or four times that. For a while treatments (counseling and medications, for the most part) worked. But these are not cures. A major reason for army generals talking about the army "needing a break" (from combat) are the looming loss of many combat experienced NCOs to PTSD. The army won't give out exact figures, partly because they don't have much in the way of exact figures. But over the next few years the army will get a clearer picture of how well they have coped with PTSD among troops who have, individually, seen far more combat than their predecessors in Vietnam, Korea, or World War II.
The problem is mainly among combat NCOs. Most of the troops are in for one enlistment (usually four years) and then leave. Junior officers get promoted out of jobs involving close combat, and officers in general are rotated between leadership and staff jobs. NCOs spend all their time with the troops, except those few who get promoted to Sergeant Major (a largely staff job as advisor to senior commanders). The Sergeants Major were among the first to note the stress problems with career NCOs (squad and platoon leaders, as well as company 1st Sergeants).
The only acceptable solution for the problem is to transfer the worst hit combat NCOs to non-combat jobs. This is a common sort of thing in the army and marines, where it's long been common for NCOs with physical conditions and injuries (resulting from the rigors of peace or wartime infantry service) to be offered transfers and retraining. Severe cases may also be offered a medical discharge (and disability pay). The loss of these skilled and experienced NCOs from combat units results in more troops getting killed or wounded in combat. But that can happen anyway if you leave a stressed out NCO in action for too long.
Then there's the problem of what to call this new situation. Many troops wish everyone would revert to the older term, Combat Fatigue. What's in a word? For the troops PTSD is just another injury and not a disorder. It's something you deal with. Like debilitating physical injuries (bad backs or knee/ foot problems) trying to cope often leads to sinking morale and a lot of people leaving the military. But with the shape the economy is in, quitting your job is not a good option.
The army and marines are dealing with PTSD head on, believing that what happened in Iraq and Afghanistan will happen again and now is the time to get ready. Experience so far has shown that PTSD can be delayed, perhaps for a long time. When a soldier does come down with it, PTSD can often be treated and its effects reversed. But not always. This has large ramifications for non-military medicine, for many civilians suffer from PTSD. That's because military recruits are screened for their ability to handle stress and resist PTSD. In the civilian community there are far more people who can acquire PTSD after exposure to much less stress. What many troops wish the brass would understand is that, as recruits, they learned that stress was a major part of the job and understood it more than the mental health mafia is willing to admit.