PTSD: The latest neuroimaging technology could mean a breakthrough for Canada's military

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Almost a century ago, soldiers returned from the First World War as changed men. They had obvious but sometimes invisible injuries: depression, flashbacks, recurrent memories, emotional and physical distress. The term coined for this phenomenon – shell shock – applied in physical and psychological cases, and while medical researchers endeavoured to understand the condition, it was seen by some as merely lack of character. In fact, hundreds of "shell-shocked" British soldiers were executed for cowardice and desertion (it wasn't until 2006 that their families were notified they would receive posthumous pardons).

Warfare evolved, and along with it the terminology around the condition. Shell shock became "combat fatigue" in the Second World War, and then "operational stress injury." But the stigma surrounding the injury endured.

Post-traumatic stress disorder is a significant issue in the Canadian military. According to a report from the Library of Parliament, one in 10 veterans released between 1998 and 2007 were diagnosed with PTSD. The figure rose to 24 per cent when other mental health illnesses were considered, including depression and bipolar disorder.

Treatment is offered to current and former soldiers, but the military's mental health services are strained. When symptoms become chronic, soldiers and veterans often have trouble working and face higher risks of alcohol abuse, drug addiction, run-ins with the law and suicide.

Some recover, others are released from the military because they are no longer well enough to serve. Before legislative changes in 2006, these veterans received lifetime payments for their injuries – now they're offered lump-sum awards.

The disorder is a disfigurement of sorts, but unlike clearly physical injuries such as tissue damage or lost limbs, doctors haven't had the equipment to scan for PTSD.

Until now.

With help from dozens of Canadian Forces soldiers who have seen combat action in Afghanistan, researchers at the Hospital for Sick Children in Toronto have used neuroimaging and analysis software to create a picture of PTSD.

The results offer hope for a tool that could take the guesswork out of a diagnosis that currently relies on self-reporting of emotional and psychological conditions. And it fuels excitement – and some skepticism – around the possibility of locating a biomarker for a psychiatric injury or illness.

The enterprising research began when Pang Shek, senior scientist at Defence Research and Development Canada (an arm of the Department of National Defence), conceived the idea of using magnetoencephalography technology to assess PTSD and mild traumatic brain injury (mTBI). He helped secure funding and put together a team of researchers from SickKids, the Canadian Forces Health Services and the United States Veterans Affairs Medical Center.

Dr. Paul Sedge, clinical leader for mental health at the Canadian Forces Operational Trauma and Stress Support Centre in Ottawa, personally recruited 50 soldiers under the age of 40, 25 of whom had a PTSD diagnosis and 25 of whom did not, for the brain-imaging experiment.

The men were shown combat-related words and images to test their speed of information processing and memory recall. Then a magnetoencephalography (MEG) machine, a sophisticated neuroimaging tool that looks like an old-fashioned, salon-style hair dryer, measured their responses to stimuli.

"The brain scans of the two groups showed huge differences in how the men with and without PTSD processed the images," said an elated Dr. Margot Taylor, director of functional neuroimaging in the Department of Diagnostic Imaging at SickKids.

"We could see heightened arousal that was maintained in the PTSD-afflicted men, and not in the men who don't suffer from the illness. The reality is those with PTSD can't let it go. Their brains stay in a hyper-aroused state," Taylor said.

She believes it's a breakthrough moment. "It's a discovery that potentially means we would be able to classify soldiers as to whether or not they have PTSD with very high accuracy, and take the guesswork out of it," she said. "PTSD is now diagnosed clinically, based on emotional and psychological symptoms. This research could lead to faster diagnosis based on an objective measure rather than having a soldier self-identify, which according to the Forces is an ongoing challenge."

Though Sedge believes "the MEG allows us to potentially understand mental illness like no other investigative tool," it will be a long time – up to 15 years – before Canadian Forces bases are equipped with mini-MEGS to provide rapid diagnosis. The sheer bulk and cost of the technology means patients can only be studied at centres like SickKids.

"To try to get this type of brain scan optimized for field work, we have to get to a portable unit, which is an EEG [electroencephalography], which will take more work and funding," Taylor said.

"It's not something we can put into our overall strategy in the near-term. It's more mid-term, so I can't put a time frame on it," Sedge said. "But 15 years ago, how many hospitals had CT [Computerized Tomography] scans or MRIs [Magnetic Resonance Imaging]?"

An accurate diagnostic tool couldn't come quickly enough for Canadian soldiers.

"PTSD is the most common type of mental-health injury we see arising in combat operations. And PTSD is the most difficult to diagnose and the most complex to treat," Sedge said.

Major Eghtedar Manouchehri, a long-time member of the Canadian Forces who completed his third and final tour in Afghanistan in 2011, can't understand why he doesn't have PTSD while so many of his friends do.

"We're talking about men and women who are sent into situations that the vast majority of people would simply run away from. Our job is exactly the opposite: We run toward horrible situations and try to put a stop to them if possible. I've seen horrendous things and I've come through relatively unscathed."

Now doing his master's degree in business at the University of Toronto's Rotman School of Management, Manouchehri volunteered to join the SickKids experiment to further his understanding of the condition. He considers himself lucky, because he knows the stigma is real.

"Very few people who are suffering from it will open up about it. It's not that the support network is not there, but the military is based on a culture of strength – so no one wants to appear 'weak,'" Manouchehri said. "These are the guys and girls that I have literally trusted with my life every day, and vice versa. Overseas, you watch each others' backs. Studies like this are important, because that kind of responsibility shouldn't end when we land back in Canada."

Sedge, a 30-year veteran with the Forces, is optimistic about the technology. He hopes that as researchers develop less-expensive MEG machines and the military makes it a priority to buy and use them, researchers will be able to develop a biomarker profile and a series of tests to diagnose PTSD, assess severity of symptoms, and then determine if treatment has worked.

Others are less sure. Renowned PTSD expert Dr. Alain Brunet, a clinical psychologist at Montreal's McGill University, advises caution. "It must all be taken with a grain of salt. The research for biomarkers in psychiatry is akin to the Holy Grail – there have been a lot of disappointments over the last 60 years," he said. "I do not know of a psychiatric illness that can be diagnosed with neuroimaging. None. Ever. So allow me to be skeptical."

He points out that with the exception of severe cases of Alzheimer's disease, neuroimaging has not been successfully used to identify mental illness.

"And that is because mental disorders are not illnesses in the same sense that we use in medicine. Illnesses in medicine all have a biomarker, but in psychiatry we rely on signs and symptoms. We diagnose the illness on the basis of its symptom, not the basis of the biomarker."

Back at Defence Research, Shek is so encouraged by the MEG study he ventures to call it "exciting." He hopes it will lead to a first-ever objective biomarker system for PTSD and mTBI.

"I firmly believe that MEG is finally enabling us to make invisible wounds visible," he said.

With a file from Renata D'Aliesio.