GEOFF BENNETT: More than 350 U.S.

service members have been injured since military action against Iran began in late February.

And U.S.

Central Command says the vast majority of those injuries are TBIs, or traumatic brain injuries.

Our Liz Landers is here with more.

LIZ LANDERS: Traumatic brain injuries have become the defining injury of post-9/11 conflicts in Iraq, Afghanistan, and now in Iran.

And while many service members are able to return to duty, the symptoms of TBI can often linger for years or even a lifetime.

Joining us now is Jayna Moceri-Brooks, who has studied combat-related traumatic brain injuries for years.

She's a professor at NYU in the College of Nursing.

Jayna, thank you so much for joining "News Hour."

JAYNA MOCERI-BROOKS, New York University: Thanks for having me.

LIZ LANDERS: Why have traumatic brain injuries for soldiers become more common, not just in this war with Iran, but also in the war on terror in the last 20 or so years?

JAYNA MOCERI-BROOKS: I think there's a number of factors for that.

One is that the type of warfare has changed, where it moved to the urban environment, where service members were experiencing a lot more IEDs and EFPs that caused the blast overpressure injury to their brains.

Also, we have such strong armor that I think previous service members would have not survived some of the blasts that our current service members have survived, and they have walked away alive, but with traumatic brain injuries from the blast.

LIZ LANDERS: TBI is sometimes called an invisible wound.

What are some of the effects or symptoms of traumatic brain injuries?

JAYNA MOCERI-BROOKS: So there's many wide-ranging effects, and they are somewhat individual to the person who experienced it.

But common symptoms include headaches, ringing in the ears, visual changes, sleep disturbances, impulse or memory challenges, difficulty concentrating.

There's a range of symptoms that are actually fairly from head to toe for these service members.

LIZ LANDERS: Why is it getting easier for the military and medical professionals to recognize and diagnose traumatic brain injuries?

JAYNA MOCERI-BROOKS: I think it's easier because, if we look at it through a neuroscience lens, instead of a psychological lens, then we can use a mechanism of injury to diagnose these injuries, which we do in emergency and trauma medicine all the time.

We know from science that being in or near a blast causes a concussion injury.

And so by mechanism alone we can diagnose these injuries.

LIZ LANDERS: You have championed the Purple Heart being awarded to service members with TBI.

Why is that so important, do you think?

JAYNA MOCERI-BROOKS: It's so important because my studies show that it actually lowers suicide risk to be given that official recognition of a combat injury.

And what I found through my study is that those who received the Purple Heart for their combat-related brain injury felt like the Purple Heart validated their uniquely invisible injury and helped them to receive care for their injury.

And, again, I found in my study that it lowered their suicide risk.

And we know that those with a combat-related traumatic brain injury are four times more likely to attempt suicide and have over double the suicide rate than those without a traumatic brain injury.

LIZ LANDERS: How can this Trump administration improve the TBI care that soldiers from this Iran war are receiving?

JAYNA MOCERI-BROOKS: I think this administration has a phenomenal opportunity to be the first to properly recognize, identify, document and treat these injuries to prevent suicide in the long term.

I think that they have an opportunity to provide early recognition through receipt of the Purple Heart and to ensure that these service members who come home have multidisciplinary care and a phased - - accelerated phased recovery plan for the years after the injury occurs to help them to heal from the injury.

LIZ LANDERS: Earlier, we spoke with Jim and Karee White from North Carolina about the reality of military families caring for returning veterans.

Their daughter, Kimmy, suffered a severe traumatic brain injury in 2014 while serving in Afghanistan and now requires full-time care.

I want to play some of that interview for you.

JIM WHITE, Military Family Member: That's a burden that will get carried quietly by families.

It'll change everything.

And - - but for us, it's been a duty.

It's been just another duty and it's been an honor to take care of our daughter.

And it's been -- for all the hardship, there's been many, many gifts that we have gotten as a result of it, the way our friends and neighbors have responded, the support we have gotten.

KAREE WHITE, Military Family Member; Service members don't choose a war.

They choose to serve their country.

That's the way we look at it.

And it's an act of faith, really, in the nation that we love to do that.

And I think the country has a lifelong obligation.

When we ask our sons and daughters to serve in harm's way, they have an obligation to stand behind them for the length of time it takes for those families that have sacrificed.

LIZ LANDERS: I think Jim and Karee demonstrate that, for every veteran that serves, there's a family behind them that supports them and also sacrifices as well.

What do those families experience?

And then also how can those families be supported?

JAYNA MOCERI-BROOKS: Yes, that's so true.

So, the families experience seeing firsthand the service' members challenges or continued symptoms from their traumatic brain injury in the rawest, most vulnerable state, and so they have really important insights to share and need to be listened to and heard and included in the care process and the care plan and the recovery plan through every aspect of it.

And I think they have important insights, that they should be brought into the visits and made sure that they're heard and being given the opportunity to share what they see behind closed doors.

LIZ LANDERS: What is your advice to some of those family members?

JAYNA MOCERI-BROOKS: My advice would be to -- to be and insert yourself in the process and to go with the service member to the office visits, to advocate for them to receive continued care and a multidisciplinary approach, to helping them through some of the symptoms that they're experiencing, and to not give up, to keep going, to keep advocating and to stick with them to make sure that they get the care that they need.

LIZ LANDERS: Jayna Moceri-Brooks, thank you so much for joining the "News Hour."

JAYNA MOCERI-BROOKS: Thanks for having me.