Fort Hood shooting: What's known about combat stress and violence?

War is a violent business, and sometimes soldiers troubled by what they’ve seen or done bring violence home with them, or they turn it on fellow soldiers in the war zone.

But the kind of violence that hit Fort Hood, Texas, Wednesday afternoon – a soldier attacking fellow soldiers before taking his own life – happens only infrequently. More typical are self-inflicted shootings or domestic violence following combat tours.

As the wars in Iraq and Afghanistan lengthened into years, the rising incidence of suicide and attacks on family members increasingly has become tied to those wars’ signature mental-health injuries: post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI).

In some cases, such combat-related injuries have been used as a defense argument in cases where soldiers have attacked civilians in Iraq and Afghanistan. Most notably, that includes Army Staff Sgt. Robert Bales, charged with wantonly killing 16 Afghan villagers in a night time rampage two years ago. He had served three tours in Iraq before deploying to Afghanistan.

Spc. Ivan Lopez, reported to be the shooter Wednesday at Fort Hood, was not engaged in combat during a four-month deployment to Iraq in 2011, but he had reported the effects of TBI, was being treated for anxiety and depression, and was in the process of being diagnosed for PTSD.

Suicide and domestic violence have been on the rise among military personnel in recent years.

Direct ties between PTSD and domestic violence can be difficult to establish, and a new study by the National Institute of Mental Health suggests that most soldiers who attempt suicide have mental health issues before enlisting. But such problems are mounting, according to data from Fort Bragg, a massive installation that, like Fort Hood, prepares combat units (including Special Forces) for deployments to war zones.

“Unfortunately, the number of unhealthy relationships appear to be growing,” the Army reported about Fort Bragg in September 2012. “From 2006 to 2011, reports show that domestic violence rose 33 percent; violent crime rose 64 percent and child abuse rose 43 percent.”

Acknowledging the strain that multiple deployments have placed on service members and their families, then-Defense Secretary Robert Gates launched a domestic awareness campaign.

Stacy Bannerman, the wife of an Army National Guard soldier first mobilized for active duty deployment in 2003, is the author of “When the War Came Home: The Inside Story of Reservists and the Families They Leave Behind.”

Citing US Department of Veterans Affairs studies, she wrote in a Daily Beast column, “Male veterans with PTSD are two to three times more likely than veterans without PTSD to engage in intimate partner violence, according to the VA, which also found that the majority of veterans with combat stress commit at least one act of spousal abuse in their first year post-deployment.”

“Since 2003, there has been a 75 percent increase in reports of domestic violence in and around Ft. Hood, where the number of soldiers diagnosed with PTSD rose from 310 in 2004 to 2,445 in 2009,” she wrote.

A survey of Iraq and Afghanistan veterans by the Washington Post-Kaiser Family Foundation this week included these findings: 52 percent say their physical or mental health is worse than it was before the wars; 41 percent report experiencing outbursts of anger; 51 percent know a service member who has attempted or committed suicide.

“More than half of the 2.6 million Americans dispatched to fight the wars in Iraq and Afghanistan struggle with physical or mental health problems stemming from their service, feel disconnected from civilian life and believe the government is failing to meet the needs of this generation’s veterans,” The Washington Post reported.

Army officials say Specialist Lopez had been assigned to a support unit in Iraq. But his mental health was clearly an issue.

“Specialist Ivan Lopez reportedly suffered a TBI … which can lead to disinhibition, impulsiveness and irritability which cannot be controlled,” says Prakash Masand, a practicing psychiatrist in New York City.

“There are reports he was also being evaluated for PTSD, and combat veterans with PTSD are two to three times more likely to exhibit violent behavior than combat veterans without PTSD,” Dr. Masand says via e-mail. “If he had PTSD combined with depression, it could have been the lethal combination that put him over the edge.”

Given the investigations that have just begun, other experts are less willing to assign cause.

Lopez’s violent episode is not common behavior for veterans with PTSD, says Harry Croft, a former Army doctor and a psychiatrist who has evaluated more than 7,000 veterans with PTSD. Other mental illness was more than likely involved, he says.

And the fact that Lopez killed himself puts him in a troubling category of US military personnel: those who commit suicide.

The number of those who took their own lives more than doubled between 2004 and 2009 to more than 30 per 100,000 among those who had served in Iraq and Afghanistan, higher than the 19 per 100,000 for the general US population. As the wars wound down, the number dropped.

The extent to which that is tied to PTSD or other forms of combat stress is harder to gauge, according to the National Institute of Mental Health report last month.

“The rise in suicide deaths from 2004 to 2009 occurred not only in currently and previously deployed soldiers, but also among soldiers never deployed,” the NIMH reported. “Nearly half of soldiers who reported suicide attempts indicated their first attempt was prior to enlistment; and soldiers reported higher rates of certain mental disorders than civilians….”

Attacks on fellow soldiers of the type Lopez carried out – particularly against officers – was dubbed "fragging" in Vietnam.

Between 1969 and 1971, the Army reported 600 fragging incidents that killed 82 Americans and injured 651. In 1971 alone, there were 1.8 fraggings for every 1,000 American soldiers serving in Vietnam, not including gun and knife assaults.

Such incidents have dropped dramatically. But in recent years there have been several incidents in the United States and Iraq. As tallied by NBC News and the Associated Press, they include:

• May 11, 2009: Five soldiers shot dead at Camp Liberty in Baghdad by Sgt. John Russell.
• Sept. 8, 2008: Spc. Jody Michael Wirawan killed himself after killing 1st Lt. Robert Bartlett Fletcher at Fort Hood.
• Feb. 25, 2008: Dustin Thorson, an Air Force technical sergeant, fatally shot his son and daughter at home on Tinker Air Base in Oklahoma in a domestic dispute with ex-wife. He had been diagnosed with PTSD after returning from Iraq.
• June 7, 2005: Two National Guard officers were killed by a grenade at headquarters in Tikrit. Staff Sgt. Alberto Martinez was later acquitted of murder in a court-martial.
• March 23, 2003: Army Sgt. Hasan Akbar tossed grenades into three tents and then fired a rifle at Camp Pennsylvania in Kuwait, killing one and injuring 14. Sergeant Akbar later received a death sentence.