When Ricardo Pereyda returned from Iraq, he thought his most difficult days were behind him.

But nothing had prepared him for the battle he would face back home.

“It was extremely difficult when I got back,” Pereyda recalls. “Here I was, a 22-year-old kid ... and I felt used up. I felt like, what now?”

Pereyda, who had served in the U.S. Army military police, was now living with a traumatic brain injury and post-traumatic stress disorder, or PTSD.

Nightmares kept him from sleeping, and his days were wrought with anxiety, anger and grief. Within a year and a half, Pereyda was medically discharged and going through a divorce.

It was then, Pereyda says, that he decided to end his life. On a quiet afternoon, with his beloved dog beside him, he wrote a letter to his loved ones and held a gun to his head. He would have pulled the trigger, he says, if it weren’t for the thought that entered his mind in that moment: the thought of the pain his death would cause his parents.

Pereyda chose to live that day, but many veterans don’t. The number of service members and veterans attempting and completing suicide has been rising for the past 10 years.

According to the Department of Veterans Affairs, 18 veterans die by suicide every day—far more than are killed in combat.

For the psychologists working to stem this tide of suicide, it’s a problem with many causes and no simple solution.