The U.S. Department of Defense has taken the huge amount of data acquired, quite recently, on battlefield concussions and other brain trauma, and established clear criteria about what degree of injury is required for the victim to be eligible for a Purple Heart medal. Unlike other types of wounds, which have obvious signs (blood, broken bones, burns and so on), brain trauma if often not immediately noted by the victim, aside from perhaps a headache, dizziness, blurred vision and the like. But long term, these brain "wounds" can have far more devastating impact than getting shot or badly burned. The injury is very real, and in the last decade, it's become possible to detect and measure the degree of injury early on.
The new criteria are meant to solve the problem of getting combat commanders to award Purple Heart medals to troops suffering from concussions (usually the result of roadside bombs.) This will also allow the many veterans suffering the long-term effects (or headed that way) of these invisible wounds to get Purple Hearts.
The army has long allowed Purple Hearts for concussions, but most commanders would not allow it. This goes back to an old (since World War II) debate on just what kind of a wound qualifies for a Purple Heart. Currently, it takes a medical officer to certify a qualifying wound and a commander to sign off on the award. Normally, if you are bleeding, badly burned, blind, permanently deaf or something is obviously broken, you qualify. Ever since the Purple Heart awards for wounds began in World War II, many troops took it as a point of honor not to take one unless they were "really hurt." Thus a lot of minor cuts (even if stitches were required) and bumps (including concussions) were not considered "really hurt." Since World War II, however, some troops gamed the system, applying for, and often getting, a Purple Heart for what most troops considered minor injuries from enemy action.
But medical science has advanced, and it's now possible to actually detect and measure the effect of a concussion. Some of them are quite serious, more so than many gunshot or shrapnel wounds. And it's now known that even one concussion (and definitely several) have long term bad effects on victims. This has led to efforts to get one of those long term effects, PTSD (post-traumatic stress disorder), eligible for a Purple Heart. Two years ago, despite vigorous lobbying by some combat veterans and U.S. military psychologists and medical officials, the U.S. Department of Defense turned down a proposal to award PTSD victims the Purple Heart medal. The Purple Heart has always been considered an award for physical wounds, and replaced earlier recognition (in the form of wound badges and such) in the 1930s. But now that invisible physical injury (concussions) are precisely defined, and eligible for the awards, PTSD Purple Hearts may not be too far behind.
But PTSD is real. The army has, over the years, developed a set of guidelines for how to recognize the symptoms of combat fatigue (or PTSD). With all the attention PTSD has gotten in the media of late, troops are more willing to seek treatment. While extreme cases of PTSD are pretty obvious, it's the more subtle ones the army wants to catch early. These are easier to cure if treated promptly. Some of the proponents for PTSD Purple Hearts believed that the award of these medals would make it easier for PTSD sufferers to seek treatment early on.
The problem with giving a medal for PTSD is that, again, except in severe cases, it's not certain who has it. A physical wound is pretty unambiguous. Even some mental injuries, like a concussion, can be proven via an x-ray or other brain image. And this is where PTSD is going. Brain activity imaging (mainly via MRI) is a rapidly growing field, and some types of PTSD can be identified this way.
But it's got a ways to go, perhaps 5-10 years, before you can put someone in an MRI (or whatever) scanner and determine if they have PTSD. That still leaves open the question of what caused the PTSD. We all suffer from PTSD to a certain extent. Accidents, a death in the family or other traumatic events can do it. But eventually, a PTSD "wound" will be as easy, well, almost as easy, to identify as a bullet wound. Then they may start handing out Purple Hearts for what was called, after the American Civil War (1861-65), "Irritable Heart," in World War I "shell shock" and in World War II "combat fatigue."