Two new studies suggest that while individuals enrolling in the armed forces do not share the exact psychological profile as socio-demographically comparable civilians, they are more similar than previously thought.

The first study found that new soldiers and matched civilians are equally likely to have experienced at least one major episode of mental illness in their lifetime (38.7 percent of new soldiers; 36.5 percent of civilians) but that some mental disorders (generalized anxiety disorder, post-traumatic stress disorder and conduct disorder) are more common among new soldiers than civilians. What's more, new soldiers are more likely than civilians to have experienced a combination of three or more disorders, or comorbidity, prior to enlisting (11.3 percent vs. 6.5 percent).

A second study focused on suicide, finding that new soldiers had pre-enlistment rates of suicide thoughts and plans at rates roughly the same as matched civilians. However, rates of pre-enlistment suicidality are higher among soldiers than civilians later in the Army career, implying that Army experiences might lead to chronicity of suicidality.

Both studies, published online today in Depression and Anxiety, are the result of a survey of 38,507 new soldiers reporting for Basic Combat Training in 2011-2012 that was carried out as part of the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS).

Concerns about the rising U.S. Army suicide rate led to Army STARRS, the largest study of mental health risk and resilience ever conducted amongU.S. Army personnel. Army STARRS is funded by the Army through the National Institute of Mental Health. The two papers, published today, focus on the ArmySTARRS survey of new soldiers about to start Basic Combat Training, whereas previous Army STARRS reports presented results from analyses of Army and Department of Defense administrative records and from a separate survey of soldiers exclusive of those in Basic Combat Training.

"The comparability of overall pre-enlistment rates of mental disorders among new soldiers and civilians is striking," said Ronald Kessler, McNeil Family Professor of Health Care Policy at Harvard Medical School and one of the senior authors. "This raises the possibility that the high rates of active pre-enlistment mental disorders reported by soldiers later in their Army careers might be due largely to these disorders becoming chronic in the context of Army experiences."

Anthony Rosellini, the lead author of the first paper and an HMS postdoctoral fellow in Health Care Policy, added "At the same time, evidence exists for selection into Army service on the basis of some disorders that can become risk factors for suicidality, suggesting that a combination of differential selection and differential chronicity might be involved in accounting for the high active pre-enlistment disorder rates later in the Army career."

The second Army STARRS paper reported that 14.1 percent of new soldiers had considered suicide at some point in their life before enlisting, 2.3 percent of new soldiers had made a suicide plan, and that 1.9 percent of new soldiers previously attempted suicide.

"These results are quite similar to those found in our survey of soldiers who were later in their Army careers and these, in turn, were similar to the rates found among matched civilians," noted the lead author of the paper, Robert Ursano, Chairman of the Department of Psychiatry at the Uniformed Services University of the Health Sciences and one of the two Army STARRS coprincipal investigators. "This means that new soldiers do not come into the Army with higher rates of suicidality than comparable civilians. And this, in turn, means that the high rates of suicidality seen later in the Army career are likely associated with experiences that happen after enlistment rather than before enlistment."

"Taken together, these results suggest the need for at least two separate kinds of interventions: Clinical interventions early in the Army career to help new soldiers reduce the chronicity of pre-enlistment mental disorders and suicidality and preventive interventions throughout the Army career to reduce onset of post-enlistment disorders and suicidality," said Matthew Nock, professor of psychology at Harvard University and a site coprincipal investigator of the Army STARRS team at Harvard Medical School.