When the body of 29-year-old Navy SEAL operator Ryan Larkin was found in his home, he was dressed in a SEAL Team shirt, flanked by the many medals he earned in service. He had survived four gruesome combat tours throughout his ten years of service. But, on a Sunday morning in 2017, he succumbed to suicide.

Getting to the truth

What didn’t kill Larkin in Iraq and Afghanistan didn’t make him stronger. Ryan was a Navy SEAL, sniper, combat medic, and instructor who taught other operators how to breach buildings with explosives. Over the years, he experienced countless blast waves and even survived a close call with an IED (improvised explosive device).

Larkin was in terrible pain and was convinced it was all due to brain damage he had suffered during service. He studied dozens of research papers on traumatic brain injury desperately trying to understand what was happening to him after doctors couldn’t find anything physically wrong with him.

Months before he took his own life, Larkin instructed his parents to donate his brain to science. Indeed, a postmortem of Larkin’s brain uncovered a pattern of brain trauma. His brain’s tissue, internal linings, and blood vessels exhibited microscopic tears that aren’t visible in standard brain scans.

“He knew,” Frank Larkin, Ryan’s father, told NBC News. “I’ve grown to understand that he was out to prove that he was hurt, and he wasn’t crazy.”

“Ryan died from combat injuries, just not right away,” the grieving father said during an interview with AP.

This tragic case highlighted major deficiencies in how the military mitigates blast risks for its servicemen. It also brought to light a woeful lack of understanding of traumatic brain injury. It’s not just veterans that should be worried. The CDC estimates that around 1.5 million people undergo at least one episode of traumatic brain injury every year, ranging from mild concussions to severe disabilities and even death.

Unseen scars

Veterans who’ve experienced considerable exposure to pressure blasts and explosives often report a range of symptoms. Some common experiences are headaches, poor sleep, trouble focusing, irritability, and failing memory.

In 2016, doctors at the Uniformed Services University of the Health Sciences dissected the brains of eight veterans who had a history of chronic or acute blast exposure. They compared the tissue features to the brains of people without exposure to explosive blasts, finding “astroglial scarring that involved the subpial glial plate, penetrating cortical blood vessels, grey-white matter junctions, and structures lining the ventricles.”

The researchers noted that “all cases of chronic blast exposure had an antemortem diagnosis of post-traumatic stress disorder”. They also mention that there were no guidelines available at the time of the study for the definitive diagnosis or treatment of blast-associated traumatic brain injuries, “partly because the underlying pathology is unknown”.

Ryan’s parents recount how their son complained about terrible headaches and had trouble sleeping. Ryan’s personality also changed for the worse after every combat tour. He stopped smiling, was often anxious, and had a quick temper.

Hidden battle

Eventually, Ryan was diagnosed with post-traumatic stress disorder (PTSD). He tried over 40 different medications, most of which only made his condition worse. The problem was that Ryan’s troubles weren’t purely psychological — there were also physical lesions in his brain. Essentially, without knowledge of these lesions he couldn’t be effectively diagnosed.

“You become very vulnerable with a lack of good science to help support your decisions,” Frank Larkin said.

“He knew that he wasn’t going to get better and that there was no turning back,” Larkin added. “The system he trusted failed him and turned on him.”

Blast-related traumatic brain injuries returned to the public’s attention recently with a tragedy. In late 2023, Robert Card, a firearms instructor and a member of the Army Reserve, opened fire in a bowling alley in Maine. He killed 18 people before dying of a self-inflicted gunshot after a two-day manhunt.

A post-mortem examination of Card’s brain revealed he had traumatic brain injuries that might have influenced his actions in his final months of life.

“Robert Card had evidence of traumatic brain injury. In the white matter, the nerve fibers that allow for communication between different areas of the brain, there was significant degeneration, axonal and myelin loss, inflammation, and small blood vessel injury,” Ann McKee from the Boston University CTE Center said in a statement issued by the family and the Concussion Legacy Foundation.

“These findings align with our previous studies on the effects of blast injury in humans and experimental models. While I cannot say with certainty that these pathological findings underlie Mr. Card’s behavioral changes in the last 10 months of life, based on our previous work, brain injury likely played a role in his symptoms.”

Call to arms

Although Card was never deployed, he was an Army instructor at the hand grenade training range. He must have been exposed to thousands of low-level grenade blasts during his job. Around the time of Card’s mass shooting, his family reports he was hearing voices and was very paranoid that others were out to get him. Card had spent two weeks undergoing psychiatric treatment.

An Army spokesman said in a statement that the findings “are concerning and underscore the Army’s need to do all it can to protect Soldiers against blast-induced injury.”

The same statement mentions that the Army is currently working to track personnel exposed to explosive blasts and document training grounds that exceed certain blast thresholds. According to a Defense Department statistic, 492,000 traumatic brain injuries have been logged in the U.S. military between 2000 and 2023, most of which are mild concussions. However, these statistics do not include veterans who suffer from chronic blast exposure, partly because the pathology is still poorly understood.

Later this year, NATO is expected to release guidelines for preventing serious brain injuries in service members, including those related to blast exposure. Although for some veterans this will be too little too late, it’s nevertheless a welcomed step in the right direction.

“This isn’t going away,” Frank Larkin said. “And my fear is that this is going to trail behind us for decades.”