KILLEEN, Texas -- This week's deadly shootings at Ft. Hood suggest that after years of trying to confront a mental health crisis, the military is still struggling to design a healthcare system that can identify and successfully treat service members who might become violent.
Army Spc. Ivan Lopez had been diagnosed with depression, anxiety and sleep disturbances and was being evaluated for post-traumatic stress disorder before he opened fire on fellow soldiers and then killed himself at Ft. Hood on Wednesday. Now the Army is confronted once again with possible correlations between mental health disorders and violence -- and how to screen for them.
Tens of thousands of veterans of the wars in Iraq and Afghanistan have been diagnosed with PTSD, but only a small minority commit violent acts. It is extremely difficult to predict those who are likely to explode into violence, according to experts in mass shootings and mental illness.
The disorder alone does not make a combat veteran or anyone else more prone to premeditated violence, experts say. But it can severely strain relationships or lead to a firing or demotion at work -- events that can push someone over the edge.
And some conditions associated with PTSD -- depression, anxiety, anger, substance abuse, suicidal thoughts -- are also associated with those who commit mass shootings.
"It's easy to identify possible predictors of a rare tragic event after the fact," Richard J. McNally, a psychology professor at Harvard University, said in an email interview. "It is much harder to predict it."
The 34-year-old Lopez had been examined by a psychiatrist last month and was prescribed Ambien, among other drugs, while undergoing evaluation for PTSD.
"We have very strong evidence that he had a medical history that indicates unstable psychiatric or psychological conditions," Army Lt. Gen. Mark Milley, the Ft. Hood commander, told reporters. Yet Lopez was not placed under any restrictions, according to the Army.
Several studies have found that combat veterans diagnosed with PTSD are two to three times more likely than other combat veterans to commit domestic violence or other violent acts, said Dr. Prakash Masand, a former Duke Univeristy psychiatrist who has studied the disorder.
"The absolute numbers are small, but the association is there," Masand said in an interview.
A study of 1,300 combat veterans by the medical school at the University of North Carolina at Chapel Hill found that 23% with PTSD or suffering from "high irritability" had been arrested for criminal offenses. Masand said the military fails to adequately follow up and monitor PTSD patients, using the same "one size fits all" treatment plan for those at high risk of violence and those who exhibit few risk factors.
Lopez, who had served in Iraq as a truck driver, did not see combat.
There were other signals, however. He bought the .45-caliber Smith & Wesson used in the shooting after his apartment was robbed, posting on Facebook how he now was "full of hatred." He also was angry that he had been granted less than two days to attend his mother's funeral in November, his family said.
On Wednesday, Lopez learned that the Army had denied his request for leave to attend to family matters in Puerto Rico, a federal law enforcement official told the Los Angeles Times on Friday.
PTSD can increase the likelihood of spontaneous aggression or violence, said Dr. Charles R. Marmar, chairman of the department of psychiatry at New York University Langone Medical Center: "It can cause outbursts when someone is provoked, but it does not provoke mass murder."
And according to Milley, an argument at Ft. Hood between Lopez and another soldier or soldiers may have provoked the shootings.
In the military, a diagnosis of PTSD is largely based on a service member's self-reporting. Because of the stigma associated with the disorder, many service members downplay any symptoms.
"We still don't have a simple test, like a pregnancy test or prostate cancer screening," to confirm PTSD, said Marmar. "We very heavily rely on the soldier to disclose symptoms and we rely on family members to corroborate them."
Those accused of mass shootings invariably are found afterward to have exhibited certain common "variables," said Ron Avi Astor, a professor of education and social work at the University of Southern California who has studied school shootings. These include expressions of intent, access to a firearm and friends and family members who heard the suspect mention the possibility of violence or suicide.
Astor cited Maj. Nidal Malik Hasan, an Army psychiatrist convicted of premeditated murder for shooting and killing 13 people and wounding more than 30 at Ft. Hood in 2009. Hasan had expressed anger and rage toward U.S. service members fighting Muslim insurgents in Iraq and Afghanistan.
"He couldn’t have been more clear" about his intentions, Astor said, yet the Army took no direct action against Hasan.
Retired Army Staff Sgt. Alonzo Lunsford of Lillington, N.C., who was shot seven times in that 2009 attack, said he is concerned Wednesday's shooting will lead those suffering from PTSD or traumatic brain injury to be further stigmatized.
"If a person has TBI or PTSD, that doesn't mean they are walking around and being a dangerous person. I have TBI and PTSD and that doesn't make me a dangerous person," he said.
Lunsford said he developed both conditions after the 2009 shooting, but he and his family have learned to live with them. "Now that the war's winding down, we need to take a long, hard look at the toll it's taking on our troops," he said.
"The military has made some progress to make sure these needs are met. But in my opinion, they haven't made enough progress."
Public perceptions of returning combat veterans as mentally unstable and prone to violence have been cited by many veterans with PTSD as reasons for being turned down for jobs. In a recent survey by the Iraq and Afghanistan Veterans of America, 24% of veterans questioned said they believed companies avoid hiring them because of mental health concerns.
Highly publicized shootings only perpetuate the stigma against veterans with the disorder, said Paul Rieckhoff, the veterans group's founder.
"In moments like this, there is a tendency by some to paint a broad brush across the entire veterans community, and it's important to guard against that mistake," Rieckhoff said. The vast majority of returning veterans are law-abiding citizens, he said, and "the acts of one individual don’t diminish or change that fact."
The military screens returning combat veterans for PTSD and other mental health issues, yet many soldiers who suffer from the disorder go undiagnosed either because their symptoms were missed or they deliberately sought to avoid a diagnosis for the disorder.
"Most people don’t want to self-identify as needing treatment, especially if they want to be promoted or be deployed," said Dr. Elspeth Ritchie, a former chief psychiatrist in the Army.
Although the Army has worked to reduce the stigma of PTSD, service members believe their career will be harmed by a diagnosis. She also described a military "treatment gap" in which just over half of those diagnosed with the disorder receive timely treatment.
At the same time, the Army's screening of recruits has come into question. According to a study released last month, nearly 1 in 5 soldiers had a common mental illness, such as depression, panic disorder or PTSD, before enlisting in the Army.
More than 8% of those soldiers had thought about killing themselves and 1.1% had previously attempted suicide, researchers found in confidential surveys and interviews with 5,428 soldiers at Army installations across the country.
And more than 8% of soldiers entered the Army with "intermittent explosive disorder," characterized by uncontrolled attacks of anger, the study found. It was the most common disorder in the study, with a pre-enlistment prevalence nearly 6 times the civilian rate.
An estimated 13% to 20% of veterans who have served in Iraq and Afghanistan have been diagnosed with PTSD, according to the Institute of Medicine. And a Rand Corp. study estimated that a third of post-9/11 veterans suffer from PTSD, TBI or depression.
These numbers, coupled with the difficulty of screening, increases the likelihood of more shootings like those at Ft. Hood, Masand said.
"Unfortunately, this is going to happen over and over again, I guarantee you," he said.
Zarembo and Hennessy-Fiske reported from Killeen and Zucchino from Durham, N.C. Times staff writer Richard A. Serrano in Washington contributed to this report.