Could soldiers, like football players, be at risk of brain disease?

Much of World War I took place in the trenches, under the unrelenting rain of artillery fire. Just like in today’s battlefields, many soldiers were repeatedly blasted by explosives.

And a curious condition began to appear: Soldiers with no obvious head injuries, but who’d been near a detonation, suffered headaches, memory loss, poor concentration, dizziness, nightmares, tremors, fatigue and hypersensitivity to sound.

At first, doctors assumed “shell shock” had a physical cause, that the structure of the brain was in some way disturbed. The medical director of one hospital found multiple hemorrhages in the brains of two shell-shocked soldiers who had no visible injuries, and proposed more exams. But his theory fell out of fashion, and those studies never took place.

A psychological view won out, which held that shell shock was a response to the intense stress of combat, especially on ill-prepared conscripts. Many dismissed shell shock as plain old malingering.

The British Army embraced the psychiatric take, which made it much easier to send troops back to the frontlines.

“If they admitted that it was psychological and a result of the war, they had to pay out money. They had to pay pensions,” says Peter Leese, author of “Shell Shock: Traumatic Neuroses and the British Soldiers of the First World War.” “And they didn’t want to do that. And they didn’t have the money to do that. The main point was to uphold military discipline. If you give into that idea of psychological symptoms then you destroy discipline and you can’t fight the war.”

British authorities ended up banning the term “shell shock,” but the symptoms stubbornly persisted. In World War II, “postconcussion syndrome” became popular for those who’d been exposed to a blast. Soon, “war fatigue” entered the lexicon. Finally, in 1980, PTSD became an official condition in the Diagnostic and Statistical Manual of Mental Disorders, thanks in part to several Vietnam veterans’ rights activists on the committee charged with looking into it.

“They wanted to secure for the veterans access to two things: continued psychiatric care… and access to disability pensions,” says Allan Young, professor of social studies in medicine at McGill University and author of “Harmony of Illusions: Inventing Post-Traumatic Stress Disorder.” Today, PTSD treatment is the Veteran Health Administration’s single largest expense, and combined with TBI, takes up more than half its budget.

But researchers say the traumatic brain injuries of today have a lot in common with the shell shock cases of World War I, and are calling into question the division between traumatic brain injury and PTSD -- one a blow to the head, the other a blow to the nerves -- that has become the medical standard. 

“Most psychiatric disorders have strong links with brian disorder and nearly all have some links,” Wellsley said. “It’s like the nature/nurture debate in genetics that used to get everyone so excited. People used to start punch-ups in meetings. Now, if you ask, ‘is it nature or nurture?’ geneticists will just roll their eyes and think you’re an idiot.”

Only recently has research emerged that connects repeated head trauma in combat to CTE. Last year, doctors at Boston University School of Medicine looked at the brains of four veterans who had experienced blast injury, and found the pathological markers of the disease.

In 2011, Dr. Bennet Omalu, who first discovered CTE in the brain of an NFL player in 2002, decided to look at the brain of a young Marine Corps veteran who had been diagnosed with PTSD and committed suicide by hanging eight months after his honorable discharge. During his two tours in Fallujah and Ramadi, the serviceman had been exposed to multiple mortar and IED blasts. His brain appeared normal during the autopsy, but showed abnormalities consistent with a diagnosis of CTE during microscopic inspection.

New research is also linking multiple concussions to a higher risk of suicide. Of active-duty soldiers in Iraq who had experienced more than one traumatic brain injury in their lives, nearly 22 percent reported thoughts or preoccupation with suicide, according to a May study, compared to 6 percent of patients who had experienced just one.

A large proportion of these servicemembers also had concussions before they even touched a battlefield, from high school sports or basic training, making them all the more vulnerable to the dangers of repeated blows to the head. More than 80 percent of traumatic brain injuries suffered by U.S. forces occur in a nondeployed setting, according to the Defense and Veterans Brain Injury Center.

Perl believes the military’s approach to concussions has been very similar to that of the NFL. The $765 million settlement the NFL reached with 18,000 retired players in August was partly over its alleged concealment of the long-term dangers of concussions, and partly the tendency of coaches to rush injured players back onto the field.

“If you weren’t bleeding, you were perhaps exposed to the IED, you’d go back to the barracks for a few days, but then you’d be back with your patrol,” he says.

Perl hopes better research could improve prevention, and also treatment for those who might be misdiagnosed as suffering something purely psychological.

“If someone has cancer, they can be depressed about having cancer. And that can interfere with the treatment of the cancer and a variety of things. And a properly trained psychologist or psychiatrist can treat the depression,” says Perl. “...And that’s important. However, that treatment will do nothing for the cancer cells.”

For those servicemen who are bothered by an initial diagnosis of PTSD, researchers say, a revised diagnosis of CTE could help encourage some servicemen to get treatment. We’ve advanced a lot when it comes to psychological illness and stigma. We no longer see traumatized soldiers as malingerers. But humans in general are still more comfortable with, and sympathetic to, diseases of the brain than the mind.

For now, however, the only way for Perl to test his theory is to get more specimens. CTE can only be definitively diagnosed postmortem, and the revelations about CTE among retired pro footballers only emerged because dozens of NFL players, including Junior Seau, the star linebacker who committed suicide last year, donated their brains to science.

Almost a century after the research was first proposed, Perl's repository is officially open. Now he's just looking for more veterans’ brains to fill it.