Concussion, or mild traumatic brain injury, occurs when a service member experiences a bump, blow, or jolt to the head that causes the head and brain to move rapidly back and forth, causing the brain to bounce around or twist in the skull and creating chemical changes in the brain and sometimes stretching and damaging brain cells (Photo by: CDC).

"When you do an MRI on such a patient, you don't see anything consistently," said Perl. "The implication is that something's wrong with the brain, but you just can't see it."

Perl established a neuropathology lab at USU dedicated to researching the acute and long-term effects of TBI and PTSD among military personnel. In the study, they analyzed brain specimens of cases with chronic blast exposure, acute blast exposure, chronic impact TBI, exposure to opiates, and a control group with no known neurological disorders for comparison.

"The one thing that kept coming up in these cases [with blast exposure] was a pattern of scarring in the brain that seemed rather unique and had really not been described previously," he said.

"And the more we worked, the more it appeared to be related to blast exposure."

The type of unique scarring they observed is called interface astroglial scarring. From there, they learned that blast waves emerging from detonations of high explosives such as improvised explosive devices and suicide bombs carry pressure waves "that expand in all different directions, at about the speed of sound, and actually pass through the skull, and through the brain, the most delicate and complex organ in the body," he said.

This led to the assumption that it must produce some damage to the brain.

"Indeed, the places where we found the scarring were places where biophysicists had previously shown that the blast wave gives off its energy," he said. "Putting two and two together, we have indicated that we think that the blast wave is damaging the brain in these locations, and this is the brain's attempt to repair itself from that damage."

"Mental health issues may be superimposed to this," he said, attributing the symptoms of concussion to "a duality of both factors - biologic factors plus functional factors - that are interplaying, interacting."

Similar Symptoms

Concussion can result in a wide variety of symptoms that can also be attributed to other causes, including headaches, irritability, fatigue, balance difficulties, sleep disturbance, dizziness, ringing in the ears, blurred vision, concentration, or memory difficulties, and other problems. But these are believed to be temporary and usually heal on their own over time, as the brain resettles back to regular functioning.

Likewise, people who have had a TBI and people who are depressed can share similar symptoms. These include low activity levels, sleep problems, difficulty controlling emotions, loss of interest in pleasurable activities, decreased energy, changes in appetite, and lack of initiation.

Similarly, Riggs said, while some people with a concussion may also have PTSD, not everyone does. He said some experts believe some people may be more vulnerable to psychological health conditions after a concussion because they were having problems already, or because they may be genetically predisposed to psychological health issues, like depression or anxiety.

Either way, the psychological health conditions that arise from concussions may require longer-term treatment.

Common treatment options include counseling and medications. Most cases of PTSD respond well to treatment, according to TBICoE.

And some complementary or alternative medical approaches such as meditation have shown to be useful, as a second-line treatment for managing PTSD.

Perl's research findings have implications for the way TBI might be diagnosed and treated in the future as well as for spurring broader research on the ways service members can be better protected as they head into situations where they might be exposed to blasts.

"We're beginning to work on if there are means by which we can detect this in living individuals," said Perl. "Our work has stimulated a number of ongoing studies to look for unique ways in which newer imaging and even fluid biomarkers can be used to identify these changes in the living."

Service members experiencing depression, anxiety, and PTSD due to concussion are not alone. The TBICoE website provides ample resources to help service members, veterans, their families, and loved ones cope with mTBI.

If you notice changes in the behavior of a loved one after concussion or fear a loved one may try to hurt themselves, urge them to call their health care provider, the Suicide and Crisis Lifeline at 988, or the Military Crisis Line at 800-273-8255 as soon as possible.