NIH–Army study identifies risks for increased military suicides

Recent findings from a large-scale study funded by the NIH and the Army demonstrate that servicemembers have higher rates of mental illness compared with the American civilian population, and the rate of suicide attempts is not linked to deployment status.

Concerns about the steady increase in military suicide over the past 10 years led the National Institutes of Mental Health (NIMH) and the Army to create the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS), an extensive study of mental health risk among U.S. Military personnel.

The study included data on suicide attempts and ideation, and it also measured the precedent of mental disorders before and after deployments including attention-deficit/hyperactivity disorder, intermittent explosive disorder and substance abuse problems. NIMH and Army researchers approached the extensive study findings with three separate analyses recently published in JAMA Psychiatry.

“These studies provide knowledge on suicide risk and potentially protective factors in a military population that can also help us better understand how to prevent suicide in the public at large,” Thomas R. Insel, MD, director of the National Institute of Mental Health, said in an NIH press release.

Historically, suicide rates among U.S. military personnel have been lower than those of U.S. civilians; however, military suicide mortality has been increasing each year since the start of the Iraq and Afghanistan conflicts, according to previous data. Researchers from all three studies did not make a conclusive statement about root causes of the increase in military suicide mortality rates over the past decade; however, study results do provide insights as to what protective factors prevent suicide currently, according to the press release. Such insights may help support the development of novel treatments that could provide therapeutic options for servicemembers in and out of combat.

Increase in suicide rates

Michael Schoenbaum, PhD, and colleagues at NIMH sought to establish a basis for future Army STARRS investigations by analyzing trends and predictors of suicide in 975,057 active Regular Army soldiers who were serving at any point from 2004 to 2009. Findings showed that the 5-year period contained 569 military deaths by suicide and 1,331 accidental military deaths.

The data focused on soldiers who died by suicide or by accident during active Army service. Schoenbaum and colleagues found that the suicide rate rose between 2004 and 2009 among soldiers who had never been deployed, who were currently deployed and who had been previously deployed as Regular Army soldiers. Actual deaths by suicide measured 12.1 per 100,000 person-years of active duty from 2004 to 2005. From 2006 to 2007, the data showed 18.1 deaths per 100,000 person-years of active duty, and 18.1 deaths per 100,000 person-years of active duty from 2008 to 2009.

The 2004 to 2009 rates of accidental death decreased among currently deployed soldiers, remained constant among the previously deployed and increased for those who were never deployed.

Schoenbaum and colleagues also identified a correlation with suicide among certain experiences and demographic traits. The findings demonstrated that a higher risk was indicated if a soldier was a man, a women who was actively deployed, young (aged 17 to 24 years), white, a junior rank, recently demoted or deployed previously or currently.

The researchers noted that “the existence of a time trend in suicide risk among never-deployed soldiers argues indirectly against the view that exposure to combat-related trauma is the exclusive cause of the increase in Army suicides.”

Attempts before deployment

In a second Army STARRS analysis, Matthew Nock, PhD, and colleagues at Harvard Medical School compared self-administered survey results on suicidal ideation, plans and attempts both before and after 5,428 soldiers were deployed. The findings showed that approximately one-third of post-enlistment suicide attempts were correlated with mental disorders that showed symptoms before a soldier enlisted.

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“Pre-enlistment mental disorders might be targets for early screening and intervention,” researchers wrote.

According to Nock and colleagues, 47% to 60% of suicidal ideation, planning, and/or attempts had pre-enlistment onsets.

“It is striking that nearly half of the soldiers who reported lifetime suicide attempts reported their first attempt occurring prior to the age at enlistment because history of suicide attempts is asked about in recruitment interviews, and applicants who report such a history are excluded from service,” they wrote.

Data showed that post-enlistment attempts are positively correlated with being a woman (odds ratio [OR]=3.3; 95% CI, 1.5-7.5), being of a lower rank (OR=5.8; 95% CI, 1.8-18.1), and having been previously deployed (OR=2.4-3.7). Suicide attempts were negatively correlated to being unmarried (OR=0.1-0.8) and assigned to Special Operations Command (OR=0.0; 95% CI, 0.0-0.0).

Nock and colleagues emphasized the importance of methods and means control, suggesting that restricting access to lethal weapons may reduce mortality.

Health, before and after

The third study by Ronald C. Kessler, PhD, and colleagues at Harvard Medical School analyzed Army STARRS data to survey the prevalence of 30-day DSM-4 mental disorders among 5,428 non-deployed soldiers both before and after enlistment.

Based on DSM-4, researchers categorized reported mental disorders into two types: internalized and externalized. Internalized disorders included major depressive, bipolar, generalized anxiety, panic and posttraumatic stress disorders. Externalized disorders included attention-deficit/hyperactivity, intermittent explosive and substance use disorders.

Data showed that 25.1% of respondents met criteria for any 30-day DSM-4 mental disorder (15.0% internalizing and 18.4% externalizing) and 11.1% for multiple disorders. Compared with a civilian sample from the National Comorbidity Survey Replication, the estimated prevalence of any 30-day DSM-4 disorder was higher among the Army population. Reported onset of at least one 30-day disorder before enlistment occurred among 76.6% of cases and although both pre- and post-enlistment onset were significantly associated with role impairment, pre-enlistment disorders were shown to be consistently powerful predictors.

Data from Kessler and colleagues’ study reflected discussion points in the study by Nock et al; both analyses noted that current measures to pre-screen soldiers for mental illness are at odds with Army STARRS data that report prevalent mental illness rates during and after deployment.

Referring to previous studies, Kessler and colleagues noted that “evidence exists for associations of childhood stresses and mental disorders with poor soldier functioning … It would be possible to expand future recruitment screening efforts to include self-reports about these pre-enlistment risk factors, but the inability to obtain objective confirmation of these self-reports could undercut the value of such efforts.”

Researchers also said that measures could be implemented to increase the resilience of new recruits in the face of deployment stress.

“Another possibility would be to build outreach and treatment programs for new soldiers based on these research findings aimed at attracting soldiers with known pre-enlistment risk factors for targeted interventions, with pre-enlistment mental disorders included in this set of risk factors,” they wrote.

For more information:

Kessler RC. JAMA Psych. 2014;doi:10.1001/jamapsychiatry.2014.28.

Nock MK. JAMA Psych. 2014;doi:10.1001/jamapsychiatry.2014.30.

Schoenbaum M. JAMA Psych. 2014;doi:10.1001/jamapsychiatry.2013.44.

Disclosure: See full studies for a complete list of relevant financial disclosures.