Iran’s one-way attack drones, used extensively to target U.S. forces across the Middle East over the last five months, could put troops at greater risk of traumatic brain injury and psychological harm, according to medical experts and veterans groups.
More than 600 service members have been wounded in action during the five-month war with Iran, with a majority suffering traumatic brain injuries, according to statements from the Pentagon and U.S. Central Command.
The Pentagon has released few details about how the injuries occurred, making it unclear how many were caused by drone attacks. But Iran’s heavy reliance on one-way attack drones has exposed U.S. troops to threats that medical professionals are still working to understand.
“This is a different kind of war and warfare that we’re having to make a shift around,” said Dr. James Kelly, chief medical scientist at the Invisible Wounds Foundation. “I think that this is something we really have to gear up to understand better and deal with.”
Kelly, one of the nation’s leading experts on brain injuries, was the founding director of the Defense Department’s National Intrepid Center of Excellence and spent years evaluating troops for TBIs in Iraq and Afghanistan.
Unlike roadside bombs that caused many brain injuries during the post-9/11 wars, drones can reach large, established bases far from traditional frontlines, potentially exposing more troops to attack.
And explosions from a drone often come from overhead, Kelly said. That leaves the upper body — especially the brain — more exposed to the blast.
“This is something that comes from above, often blows up in the air, or hits something up in the air,” he said. “Anatomically the head is much more vulnerable under those circumstances.”
Iranian-backed militants have for years used drones to target U.S. forces in the region, including in the 2024 attack on the Tower 22 outpost in Jordan that killed three Army Reserve soldiers.
But Operation Epic Fury marks the first time U.S. troops have faced sustained drone attacks on this scale, with repeated salvos over an extended period.
According to U.S. estimates, Iran fired more than 2,000 drones during the first few days of the war, striking high-rises in Bahrain, targeting oil fields in Saudi Arabia and killing six U.S. soldiers at an Army outpost in Kuwait.
Iran’s Shahed-136 drone measures about 8 by 11 feet and can reach 115 mph carrying a 120-pound warhead. The Pentagon is developing cheaper ways to counter drones but still relies heavily on costly interceptors, including Patriot missiles, to shoot them down.
Some are still getting through. Of the 8,500 missiles and drones Iran has launched, about 100 penetrated air defenses, The Washington Post reported, citing a U.S. official.
Pentagon officials have emphasized that most troops injured in the Iran war quickly returned to duty. But decades of research show that brain injuries can have long-term effects and remain difficult to diagnose and treat.
That was evident after Iran’s 2020 ballistic missile attack on Al Asad Air Base in Iraq. No U.S. casualties were initially reported, but continued screening eventually identified 110 service members with traumatic brain injuries.
The prevalence of TBIs in the current war does not necessarily mean troops are suffering brain injuries at a higher rate than in previous conflicts. Awareness of the injuries has grown significantly during the post-9/11 wars, making comparisons across conflicts difficult.
But the scale of the problem is well-established. The Defense Department reported nearly 500,000 traumatic brain injuries between 2000 and 2025, a number that continues to grow, said Kelly Parker, director of Independence Services at the Wounded Warrior Project.
“Many of them will need care for the rest of their lives, or some type of support for the rest of their lives,” Parker said.
There is still limited understanding of how drone attacks differ from more traditional munitions strikes, but the Russia-Ukraine war has given researchers and medical experts some insight into their potential effects.
As drones proliferate in Ukraine, soldiers have shown more upper-body and blast injuries along with signs of intense anxiety and hypervigilance, said Dr. Joseph Bonvie, a retired U.S. Navy operational psychologist and senior director of clinical services for Home Base, a Boston-based nonprofit that treats veterans and service members.
Bonvie traveled to Ukraine last year, where he met with a soldier who described being caught off guard by a Russian drone attack.
The soldier endured repeated strikes over several hours and lost consciousness while a reconnaissance drone filmed the entire incident. He survived, only to later encounter footage of his own attack circulating on social media.
That combination of battlefield lethality and digital exposure represents a new aspect of modern warfare, Bonvie wrote in a case study, with potential implications for psychological trauma, moral injury — distress over deeply troubling experience — and clinical care that are yet to be fully understood.
“That is a whole new bag of trauma exposure that we haven’t seen before,” Bonvie told Stars and Stripes.
Meanwhile, advocacy groups are warning about a steep decline in Pentagon funding for brain injury research. Funding for medical research into traumatic brain injuries fell from $175 million in 2024 to $40.5 million in 2026 — a drop of more than 75%.
Groups such as the Veterans of Foreign Wars are lobbying Congress for more funding for brain injury research, better diagnostic tools and long-term treatments for veterans.
“Ongoing conflict in the Middle East is increasingly exposing our nation’s service members to these blast injuries with the increasing use of drone and rocket attacks,” said Craig Breckheimer, senior vice commander for the VFW’s Department of Europe.
One of the biggest challenges is the lack of an objective test for brain injuries. Doctors traditionally have relied on questionnaires and clinical observations to make diagnoses.
Army medical leaders recently began fielding a handheld device that uses blood samples to quickly detect biomarkers — proteins released into the bloodstream after a brain injury — that can help determine whether a service member needs further treatment.
The tool is currently being used by the 10th Army Air and Missile Defense Command, which has units deployed to Jordan and lost two soldiers in a deadly July 17 attack.
Medical professionals say little is also known about the effects of repeated blasts on service members. A 2024 Massachusetts General Hospital study of 30 active-duty U.S. Special Operations Forces personnel found a possible association between greater blast exposure and certain changes in the brain.
Researchers also noted that the effects of repeated blast exposure can be difficult to pinpoint to a single incident, potentially complicating efforts to explain cognitive, physical and psychological symptoms.
The potential for repeated blast exposure from drone attacks has added urgency to efforts to better understand and diagnose TBIs, experts say.
“Military innovation, weaponry innovation, has always been commensurate with medical innovation for all the wrong reasons,” Bonvie, at Home Base, said. “And I think that’s where we are again.”