Among current and former military personnel, the risk of suicide is related to the same mental health disorders found in civilian populations rather than to military experience, a report published online Aug. 6 in JAMA suggests.
In an analysis of data from a large prospective longitudinal cohort of personnel from all branches of the service, increased suicide risk was strongly associated with manic-depressive disorder, now commonly called bipolar disorder; depression; and alcohol-related problems but was not associated with military-specific factors such as combat experiences, long deployments, or multiple deployments, reported Cynthia A. LeardMann of the department of deployment health research, Naval Health Research Center, San Diego, and her associates.
Ms. Cynthia LeardMann
Their findings indicate that the best means of mitigating suicide risk in military personnel are screening for mental and substance use disorders, obtaining an accurate psychiatric history, and recognizing potential suicidal behaviors early, together with providing high-quality mental health treatment, the researchers said.
Suicide rates in the military increased sharply beginning in 2005 and continued to rise each year until leveling off in 2009. Yet, suicide still remains a rare outcome in service personnel.
To examine factors associated with suicide risk in the military, Ms. LeardMann and her colleagues analyzed data from the Millennium Cohort Study, which prospectively records the health impact of military service in a randomly selected sample of service members using periodic surveys. The Millennium Cohort includes a large population of active, reserve, and National Guard members in the Army, Navy/Coast Guard, Marine Corps, and Air Force.
For their study, Ms. LeardMann and her associates assessed the records of 151,560 participants in the Millennium Cohort who were surveyed in 2001 through 2008, the last year for which complete data have been collected. Suicides and other deaths were identified through these records as well as through the National Death Index and the Department of Defense Medical Mortality Registry.
Factors related to deployment that were considered in the analyses included the number of deployments; length of deployments; whether or not the subject had encountered dead or decomposing bodies, witnessed people being killed, discharged a weapon, or felt in great danger of being killed; and whether the subject had witnessed abuse such as torture, beating, or rape. Nonmilitary stressful life events also were considered, such as divorce, severe illness, or death of a close loved one.
During up to 7 years of follow-up – the equivalent of 707,493 person-years of observation – 646 of these subjects died, including 83 (12.8% of total deaths) who died from suicide. The overall crude rate of suicide was 11.73 per 100,000 person-years.
Crude suicide rates were highest among study subjects who had manic-depressive disorder (87.55 per 100,000), alcohol-related problems (27.67 per 100,000), and depression (26.94 per 100,000). Subjects who were currently deployed, whether or not they had combat experience, were no more likely than nondeployed subjects to die from suicide, the investigators reported (JAMA 2013;310:496-506).
In a more refined analysis of the data, suicide risk was again strongly associated with manic-depressive disorder (hazard ratio, 4.35), alcohol-related problems (HR, 2.56), and depression (HR, 1.96), and was not associated with any deployment-related factors.
In an additional nested case-control analysis, suicide risk was independently and strongly associated with manic-depressive disorder (odds ratio, 7.38), depression (OR, 2.68), and alcohol-related problems (OR, 2.30). Again, no association was found between suicide risk and deployment factors.
In a subgroup analysis involving only Army personnel, manic-depressive disorder (HR, 5.96) and alcohol-related problems (HR, 3.86) were significantly associated with suicide risk. Depression was not, but that might have been attributable to inadequate statistical power because there were not enough cases in this subgroup, the investigators said.
These findings "are not consistent with the assumption that specific deployment-related characteristics ... are directly associated with increased suicide risk. Instead, the risk factors associated with suicide in this military population are consistent with civilian populations, including male sex and mental disorders," Ms. LeardMann and her associates said.
"Studies have shown a marked increase in the incidence of diagnosed mental disorders in active-duty service members since 2005, paralleling the incidence of suicide. This suggests that the increased rate of suicide in the military may largely be a product of an increased prevalence of mental disorders in this population, possibly resulting from indirect cumulative occupational stresses across both deployed and home-station environments over years of war," they said.
The researchers noted that their analyses could not capture suicides that occurred since 2008. "It is possible that the cumulative strain of multiple and lengthy deployments only began to be reflected in suicide rates toward the later stages of the conflicts [in Iran and Afghanistan]," and thus could not be accounted for in this study.