The experience of killing in war was strongly associated with thoughts of suicide, in a study of Vietnam-era veterans led by researchers at the San Francisco VA Medical Center (SFVAMC) and the University of California, San Francisco (UCSF).
The scientists found that veterans with more experiences involving killing were twice as likely to have reported suicidal thoughts as veterans who had fewer or no experiences.
To evaluate the experience of killing, the authors created four variables - killing enemy combatants, killing prisoners, killing civilians in general and killing or injuring women, children or the elderly. For each veteran, they combined those variables into a single composite measure. The higher the composite score, the greater the likelihood that a veteran had thought about suicide.
The relationship between killing and suicidal thoughts held even after the scientists adjusted for variables including post-traumatic stress disorder (PTSD), depression, substance use disorders and exposure to combat.
The study, which was published electronically on April 13 in the journal Depression and Anxiety, was based on an analysis of data from the National Vietnam Veterans Readjustment Survey, a comprehensive study of a nationally representative sample of Vietnam-era veterans.
The authors cited other research indicating that veterans are at elevated risk of suicide compared to people with no military service. They noted that by 2009, the suicide rate in the U.S. Army had risen to 21.8 per 100,000 soldiers, a rate exceeding that of the general population.
"The VA has a lot of very good mental health programs, including programs targeting suicide prevention. Our goal is to make those programs even stronger," said lead author Shira Maguen, a clinical psychologist at SFVAMC and an assistant clinical professor of psychiatry at UCSF. "We want clinicians and suicide prevention coordinators to be aware that in analyzing a veteran's risk of suicide, killing in combat is an additional factor that they may or may not be aware of."
Notably, the scientists found that the only variable with a significant link to actual suicide attempts among the veterans was PTSD - a finding that replicated earlier studies, according to Maguen. Thus, she said, the link between killing and suicide attempts was not as significant as the link between killing and suicidal thoughts.
Maguen noted that, currently, the mental health impact of killing is not formally evaluated as part of VA or Department of Defense mental health treatments, nor typically taken into consideration when assessing a veteran's risk of suicide.
"We know from our previous research how hard it is to talk about killing," Maguen cautioned. "It's important that we as care providers have these conversations with veterans in a supportive, therapeutic environment so that they will feel comfortable talking about their experiences."
The overall goal, she said, "is to look back and understand some lessons of the past that we can apply to the present. Talking with people who have had suicidal thoughts can potentially give us insights into why suicides occur, and hopefully help us prevent them."
Co-authors of the study are Thomas Metzler, MA, of SFVAMC and UCSF; Jeanne Bosch, MPH, of SFVAMC; Charles R. Marmar, MD, of New York University Langone Medical Center, New York; Sara J. Knight, PhD, of SFVAMC and UCSF at the time of the study; and Thomas C. Neylan, MD, of SFVAMC and UCSF.
The research was supported by funds from the Department of Veterans Affairs.
SFVAMC has the largest medical research program in the national VA system, with more than 200 research scientists, all of whom are faculty members at UCSF.
UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.