The largest and most comprehensive study on veterans who sought treatment for depression in the government's health care system was conducted by the Department of Veterans Affairs and University of Michigan. The joint effort detailed records from more than 800,000 veterans, including troops returning from Iraq and Afghanistan, revealed that veterans receiving treatment for depression are no more likely to take their own lives as compared with civilian patients.

The study yielded 1,683 suicides in all, a rate of less than one-quarter of one percent ? far lower than some past estimates. However, experts cautioned against applying the findings too widely, because most former servicemen and women with mental health problems do not seek treatment in the Veterans Affairs system.

Contrary to most studies of non-veterans, the risk of suicide generally goes up with age, the highest rate among those ages 18 to 44, but dropped about 20 percent for those ages 45 to 64, and then rose again after that.

Paradoxically, the research suggested that those who had symptoms of post-traumatic stress disorder (PTSD) as well as depression were at significantly lower risk of suicide than those without trauma symptoms. Veterans being treated for both conditions were 20% less likely to commit suicide than those who were treated for depression alone. People suffering from two conditions are usually considered to be at higher risk for harm than those with one.

According to the Dr. Marcia Valenstein, senior author of the team from the University of Michigan, ?It may be that those being treated for PTSD have more access to services, more psychotherapy visits, just more mental health services in general.?

In addition to that, Dr. Valenstein said that the veterans being treated for post-traumatic stress disorder were more likely than the others to receive income supplements from the government to cover the disability, which could also help account for the difference.

The Veterans Affairs and Defense Departments have been investigating suicide risk closely since a study of combat troops in 2003 found high rates of suicide. In another recent study, Oregon researchers found that veterans were about twice as likely to kill themselves as were people who had not served in the military.

The American Journal of Public Health published the new analysis online which focused only on those veterans who sought treatment for depression in the government's health care system and suggested that they might be different in some ways from others in treatment.

Mark Kaplan, a professor of community health at Portland State University in Oregon said that the s an important study and adds a lot to what we know about this population.?

In this new research study, the team evaluated records for 807,694 veterans being treated in the V.A. system from April 1999 to September 2004, which included men and women who had served in Vietnam, the Persian Gulf war, Iraq and Afghanistan. However, the researchers did not do separate analysis for each.

Moreover, the study did not evaluate the methods used in the suicides. In the Oregon study led by a community health practitioner named Dr. Mark Kaplan was published last summer. His study indicated that more than 80% of veterans? suicides were found to have been committed with a gun compared to 55% among non-veterans.