TORONTO -- A former U.S. Marine is bringing his real-life experience to season four of the popular TV drama “This is Us,” as the show plunges deeper into the struggles of post-traumatic stress for soldiers.

James LaPorta is a veteran who has had multiple deployments in Afghanistan in the past, and now works as a journalist. It was journalism that first brought him into contact with “This is Us” show creator Dan Fogelman, he told CTV News -- at first, he was just looking to interview him.

LaPorta had no idea that soon he would be the show’s new military consultant.

“This Is Us,” a show that follows the lives of the Pearson family, has explored the effects of war before within the series -- the patriarch of the family, Jack, fought in the Vietnam War with his brother Nicky.

LaPorta said he had been a “fan of the show from the beginning,” but when it started delving further into that Vietnam War storyline, he was impressed by the accuracy.

“They were just getting a lot of things right,” he said. “But not only just getting a lot of things right from a historical standpoint … they just captured what it’s like to come home and what it’s like to sort of be back in civilian life after rotating out of the military.”

He said that any veteran could “relate” to that feeling of displacement, not matter which war they had fought in.

“The way I got involved (in ‘This is Us’) was … I reached out and (said) ‘Hey, I wanted to do a story,’ and found out that ‘This is Us’ had brought in Tim O’Brien, who wrote probably one of the best books to come out of Vietnam.”

That book was “The Things They Carried,” a collection of linked short stories that O’Brien wrote based on his experiences as a soldier in the Vietnam War. The collection was nominated for a Pulitzer.

“(O’Brien) wrote the Vietnam storyline (for ‘This Is Us’),” LaPorta said.

LaPorta arranged an interview with Fogelman and O’Brien. But an hour before the interview was set to take place, LaPorta received devastating news.

“I had learned that a marine that I had served with in Afghanistan had taken their own life,” he said. “And as you can imagine, the interview didn’t go well. I sort of broke down on the phone call.”

He said that as a journalist, it was an embarrassing moment for him. But Fogelman didn’t see it that way. LaPorta said Fogelman told him, “You’re being a little too hard on yourself. You’re human.”

The creators later told LaPorta that they were inspired by his story, and he said they asked him to “help us craft season four.”

Season four brings new characters and a new look at PTSD with the storyline of Cassidy Sharp, played by Jennifer Morrison.

Cassidy is an accomplished military officer who struggles to deal with civilian life after returning home from the Middle East. After alienating her family, she ends up seeking help in a support group for veterans. Her first connection with a member of the Pearson family comes at the end of the first episode of season 4, when her group session is disrupted by Nicky throwing a chair through the window.

“I became incredibly obsessed with getting everything right,” LaPorta said about working on the show.

It wasn’t the regular fans of the show that he was worried so much about letting down-- it was other veterans who could watch the season and see something out of place.

“And so actually everything in Cassidy’s storyline … is either a true story, or comes from a real fact, or comes from a real statistic,” he said. “We made up very little, if anything at all.”

He did “tons of research” to prepare for the first episode of season four alone, he said, and the showrunners did their own research to match. LaPorta said that even details that might not be noticed by every viewer were still important to the show’s creative team to get right, down to small things like dyeing the actors’ beards to make sure they matched real life cultural practices.

The most important thing for him is to depict PTSD accurately and help raise awareness, he said.

“The one message that everybody should take away from this storyline, or even just being a casual watcher of ‘This Is Us,’ is that there is help out there,” LaPorta said. “The best way to take care of post-traumatic stress -- or any stress that you’ve been through, regardless if it’s war or not – is to find that support group … go through it as a community.”

He wants “This is Us” viewers to know that “you don’t have to go through life alone. Nobody is meant to be alone.”