Understanding Suicidal Behavior among US Army Soldiers: Intent, Lethality, and their Prediction
Catherine L. Dempsey,1 James A. Naifeh,1 Patti L. Vegella,1 Matthew K. Nock,2 Christina L. Wryter,1 Carol S. Fullerton,1 David M. Benedek,1 Steven G. Heeringa,3Ronald C. Kessler,4 Murray B. Stein,5 Lisa J. Colpe,6 Michael Schoenbaum,6 & Robert J. Ursano1
1Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences; 2Harvard University; 3University of Michigan; 4Harvard Medical School; 5University

BACKGROUND• The US Army suicide rate has sky-rocketed over the past
decade, yet our understanding of suicidal behaviors amongSoldiers remains very limited. The Army Study to Assess Risk
and Resilience in Servicemembers (Army STARRS; www.
ArmySTARRS.org)1 is a multicomponent epidemiological andneurobiological study designed to generate actionable,evidence-based recommendations to reduce Army suicides andincrease knowledge about risk and resilience factors forsuicidality.*• This is the first report on Soldier Health Outcomes Study-A (SHOS-A), an Army STARRS case-control study ofSoldiers hospitalized due to a suicide attempt. We examined the severity and predictors of suicide intent andmedical lethality among recent Army suicide attempters using data from a structured clinical interview.

RESULTS
I. DESCRIPTIVE STATISTICS• Suicide attempt history: Over 51% of cases reported 2 or more lifetime suicide attempts, with 26% reporting • Method of attempt: Prescription drug use was the most common method of suicide attempt overall (30%),although a greater proportion of females (48%) than males (27%) reported prescription drugs as their method.
3 or more.
The most common multiple method used was alcohol and prescription drug use (Figure 2).
• Recent substance use: 57% reported use of alcohol and/or illicit drugs within a week of hospitalization, and
30% reported consuming at least 4 alcoholic drinks in the 24 hours prior to attempting suicide.

TotalFemales

Males

Percent (%)• In a multivariate regression model, having 3 or more lifetime suicide attempts remained a significant predictorof lethality (B=-1.19, p=.04) when controlling for gender, suicide intent, any alcohol or illicit drug use in theweek prior to hospitalization, and number of alcoholic drinks in 24 hours prior to attempt.

• Army suicide attempters (N=120) wererecruited from psychiatric inpatient units atfive military treatment facilities in thecontinental US. Patients were excluded
based on active psychosis or medical
incapacity, as determined by the attending
physician.

PsychiatricSymptoms

Problem with
Family/Spouse

Other

Job stress

Legal/Criminal
problemMedical Chapter

Contributing Circumstances
1. Participants may be counted in more than one category (i.e., categories are not mutually exclusive).

• Cases were predominantly male (82%),
White Non-Hispanic (56%), at least highschool educated (87%), married (59%), andwith a mean age of 28-years-old.

Figure 2. Primary method of suicide attempt1,2
50

TotalFemales

Males

454035• Suicide attempt history & characteristics: An adapted version of the Self-Injurious Thoughts and Behaviors
Interview (STBI)4 was used to assess the number of previous suicide attempts and the characteristics of the mostrecent attempt (i.e., the attempt that precipitated current hospitalization). Here we examined STBI items assessing
method of actual or attempted injury, the circumstances reported as contributing to the attempt, alcohol or illicit
drug use in the week prior to hospitalization, and number of alcoholic drinks in the 24 hours prior to attempt.

30

Percent (%)

Measures:

25
20
15
105

GenderFemaleMale
Method of Attempt
Own prescription drugs
1
Illicit drugs
Over-counter drugs
Firearms
Hanging
Sharp object
Auto exhaust
Multiple Methods
2
Other
3
Primary Circumstance of Attempt
Job stress
Problem with family/spouse
Psychiatric symptomsLegal/criminal problem
Army medical chapter
4
OtherLethality(LS score)

Suicide Intent(SIS score)

Characteristics

Sample:• Suicide intent: Level of suicide intent (i.e., intent to die) was assessed using the Suicide Intent Scale (SIS)5
based on behaviors before, during, and after the most recent suicide attempt. The SIS was modified foradministration as a structured interview. The interviewer rated each of the 15 items on a 0-2 scale, with a higher
summary score indicating greater suicide intent.

II. PRIMARY OUTCOMES• Predictors of suicide intent: None of the predictor variables considered here were associated with suicide• Reported contributing circumstances: Psychiatric symptoms were the most frequently reported contributing
intent in either univariate or multivariate analyses.
circumstances among both males (86%) and females (71%). Job stress (including bullying) was the second
most frequently reported circumstance among females (67%), whereas family or spouse problems was the • Predictors of lethality: In univariate regression models, Soldiers who reported 3 or more lifetime suicide
second most common among males (58%) (Figure 1).
attempts had a less lethal recent attempt than those for whom the current attempt was their first (B=-1.21,p=0.03). There was a marginal association between consuming 2 or more alcoholic drinks versus none in theFigure 1. Circumstances reported as contributing to the suicide attempt1,2
24 hours prior to attempt with higher lethality (B=0.87, p=0.09). Suicide intent was not associated with lethality
at the univariate level (B=0.04, p=0.39).

• Prior studies have reported conflicting findings regarding the association between suicide intent and lethality, withsome studies finding a strong correlation (i.e., the greater the intent to die, the more lethal the attempt)2 and othersfinding no such association.3 One reason for this divergence of findings could be problems in the measurement ofthese constructs.

METHODof California, San Diego; 6National Institute of Mental Health

N

Mean

(SD)

Mean

(SD)

2198

15.3
17.2

(4.4)
(5.0)

4.2
4.3

(2.0)
(2.8)

36
3
124
14
135
26
7

16.0
19.7
17.0
18.0
17.0
16.5
20.4
17.0
16.0

(4.7)
(9.5)
(6.2)
(4.8)
(5.2)
(3.7)
(3.2)
(5.8)
(2.2)

5.1
6.3
4.6
0.0
2.1
4.5
4.6
4.6
3.2

(2.4)
(0.6)
(3.1)
(0.0)
(1.7)
(1.7)
(3.2)
(2.5)
(3.0)

18
26
56
6
5
9

16.6
16.4
17.8
15.0
14.0
15.6

(5.4)
(4.7)
(4.0)
(9.1)
(5.4)
(6.9)

4.2
3.5
4.5
5.7
6.6
2.9

(2.3)
(2.6)
(2.6)
(2.5)
(2.8)
(2.3)

1. Illicit drugs include someone else’s prescription drugs.

0
PrescriptiondrugsMultipleMethods

Hanging

Sharp object Over-counterdrugs

Other

Auto exhaustFirearms

Illicit drugs

2. Other method includes: poisoning, jumping from height, train/car, alcohol.
3. Participants were categorized based on the contributing circumstance they identified as primary (i.e., categories are mutually exclusive).

• Lethality: Level of medical lethality (i.e., danger to life) resulting from the recent suicide attempt was assessedusing the Beck Lethality Scale (LS).6 The interviewer rated lethality on a 0-10 scale in one of 8 categories(corresponding to method of attempt) based on participant-reported injuries and medical treatment, with a higherscore indicating greater medical lethality. When multiple methods were used, lethality was determined based on
the category with the highest score.
Interrater Reliability:• To assess interrater reliability, interviewers at each study site took turns administering the interview via
teleconference to actors trained to simulate psychiatric symptoms. During each teleconference, interviewers at theother sites listened silently and independently coded the responses (coding decisions were not discussed).
Average interrater reliability (Cohen’s Kappa) for the 8 simulated interviews was 0.82 for items assessing
alcohol/drug use (STBI), 0.54 for items assessing method and circumstances (STBI) and lethality (LS), and 0.57
for items assessing suicide intent (SIS).

Method of Suicide Attempt

4. Other circumstances include: financial problems, health problems (self), health problems/death (other), and unknown.

1. Method categories are mutually exclusive.
2. Other includes: poisoning, jumping from height, train/car, and alcohol.

CONCLUSIONS• Consistent with some prior civilian studies,3 but not with others,2 we found no association between suicide intent and medical lethality in this sample of hospitalized US Army suicide attempters. It is important to continue to work on
resolving this complex relationship, as evidence clearly demonstrates that both suicide intent and lethality play a critical role in understanding and preventing suicide.
• The finding that more lifetime suicide attempts was associated with a less lethal most recent suicide attempt conflicts with evidence from civilian research indicating repeated suicide attempts tend to increase in severity.7 This
discrepancy may be due to sociodemographic, psychological, and environmental exposure characteristics that differentiate Soldiers from the civilian population. It may also be due to recall and reporting bias in the assessment oflethality among SHOS-A cases, as the civilian findings were based on lethality ratings derived from medical records. It would likely be informative for future Army studies to examine the correspondence between self-reported andadministrative indicators of lethality.

Analyses:

References:• Analyses were conducted using SAS version 9.3. Missing SIS values were imputed using the modal response forthat item within the sample. The single participant missing data on other variables was excluded. Predictors ofsuicide intent and lethality were examined in univariate and multivariate ordinary least squares regression models.

1. Ursano, R. J., Colpe, L. J., Heeringa, S. G., Kessler, R. C., Schoenbaum, M., & Stein, M. B. (2014). The Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS). Psychiatry: Interpersonal and Biological Processes, 72(2), 107-119.
2. Haw, C., Hawton, K., Houston, K., & Townsend, E. (2003). Correlates of relative lethality and suicidal intent among deliberate self-harm patients. Suicide and Life Threatening Behavior, 33(4), 353-364.
3. Brown, G. K., Henriques, G. R., Sosdjan, D., & Beck, A. T. (2004). Suicide intent and accurate expectations of lethality: Predictors of medical lethality of suicide attempts. Journal of Consulting and Clinical Psychology, 72(6), 1170-1174.
4. Nock, M. K., Holmberg, E. B., Photos, V. I., & Michel, B. D. (2007). Self-Injurious Thoughts and Behaviors Interview: Development, reliability, and validity in an adolescent sample. Psychological Assessment, 19(3), 309-317.
5. Beck, A. T., Schuyler, D., & Herman, I. (1974). Development of suicidal intent scales. In A. T. Beck, H. L. P. Resnick & D. J. Lettieri (Eds.), The prediction of suicide (pp. 45-56). Bowie, MD: Charles Press.
6. Beck, A. T., Beck, R., & Kovacs, M. (1975). Classification of suicidal behaviors: I. Quantifying intent and medical lethality. American Journal of Psychiatry, 132(3), 285-287.
7. Carter, G., Reith, D. M., Whyte, I. M., & McPherson, M. (2005). Repeated self-poisoning: increasing severity of self-harm as a predictor of subsequent suicide. British Journal of Psychiatry, 186, 253-257.
*Army STARRS was sponsored by the Department of the Army and funded under cooperative agreement number U01MH087981 with the U.S. Department of Health and Human Services, National Institutes of Health, National Institute of Mental Health (NIH/NIMH). The contents are solely the responsibility of the authors and do not necessarily represent the views of theDepartment of Health and Human Services, NIMH, Department of the Army, Department of Defense, Uniformed Services University of the Health Sciences, or Center for the Study of Traumatic Stress. The funders had no role in study design, data collection, and analysis, decision to publish, or preparation of the manuscript. Conflicts of interest: none.