When Michael was discharged, DeBow picked him up at the airport — and was staggered. “When he got off the plane and I picked him up, it was like he was an empty shell,” she told me. “His body was shaking.” Michael began drinking and abusing drugs, his mother says, and he terrified her by buying the same kind of gun he had carried in Iraq. “He said he slept with his gun over there, and he needed it here,” she recalls.

Then Ryan returned home in 2007, and he too began to show signs of severe strain. He couldn’t sleep, abused drugs and alcohol, and suffered extreme jitters.

“He was so anxious, he couldn’t stand to sit next to you and hear you breathe,” DeBow remembers. A talented filmmaker, Ryan turned the lens on himself to record heartbreaking video of his own sleeplessness, his own irrational behavior — even his own mock suicide.

One reason for veteran suicides (and crimes, which get far more attention) may be post-traumatic stress disorder, along with a related condition, traumatic brain injury. Ryan suffered a concussion in an explosion in Iraq, and Michael finally had traumatic brain injury diagnosed two months ago.

Estimates of post-traumatic stress disorder and traumatic brain injury vary widely, but a ballpark figure is that the problems afflict at least one in five veterans from Afghanistan and Iraq. One study found that by their third or fourth tours in Iraq or Afghanistan, more than one-quarter of soldiers had such mental health problems.