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Unit cohesion during deployment and post-deployment mental health: is cohesion an individual- or unit-level buffer for combat-exposed soldiers?

Published online by Cambridge University Press:  10 June 2020

Laura Campbell-Sills Open the ORCID record for Laura Campbell-Sills [Opens in a new window] ,
Patrick J. Flynn ,
Karmel W. Choi ,
Tsz Hin H. Ng ,
Pablo A. Aliaga ,
Catherine Broshek ,
Sonia Jain ,
Ronald C. Kessler ,
Murray B. Stein  and
Robert J. Ursano
...Show all authors
Laura Campbell-Sills*
Affiliation:
Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
Patrick J. Flynn
Affiliation:
Department of Management, Innovation, and Entrepreneurship, Poole College of Management, North Carolina State University, Raleigh, NC, USA
Karmel W. Choi
Affiliation:
Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA Psychiatric and Neurodevelopmental Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA Stanley Center for Psychiatric Research, Broad Institute, Boston, MA, USA
Tsz Hin H. Ng
Affiliation:
Department of Psychiatry, Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD, USA Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
Pablo A. Aliaga
Affiliation:
Department of Psychiatry, Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD, USA Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
Catherine Broshek
Affiliation:
Department of Psychiatry, Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD, USA Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
Sonia Jain
Affiliation:
Department of Family Medicine and Public Health, University of California San Diego, La Jolla, CA, USA
Ronald C. Kessler
Affiliation:
Department of Health Care Policy, Harvard Medical School, Boston, MA, USA
Murray B. Stein
Affiliation:
Department of Psychiatry, University of California San Diego, La Jolla, CA, USA Department of Family Medicine and Public Health, University of California San Diego, La Jolla, CA, USA VA San Diego Healthcare System, San Diego, CA, USA
Robert J. Ursano
Affiliation:
Department of Psychiatry, Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
Paul D. Bliese
Affiliation:
Department of Management, Darla Moore School of Business, University of South Carolina, Columbia, SC, USA
*
Author for correspondence: Laura Campbell-Sills, E-mail: l2campbellsills@health.ucsd.edu
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Abstract

Background

Unit cohesion may protect service member mental health by mitigating effects of combat exposure; however, questions remain about the origins of potential stress-buffering effects. We examined buffering effects associated with two forms of unit cohesion (peer-oriented horizontal cohesion and subordinate-leader vertical cohesion) defined as either individual-level or aggregated unit-level variables.

Methods

Longitudinal survey data from US Army soldiers who deployed to Afghanistan in 2012 were analyzed using mixed-effects regression. Models evaluated individual- and unit-level interaction effects of combat exposure and cohesion during deployment on symptoms of post-traumatic stress disorder (PTSD), depression, and suicidal ideation reported at 3 months post-deployment (model n's = 6684 to 6826). Given the small effective sample size (k = 89), the significance of unit-level interactions was evaluated at a 90% confidence level.

Results

At the individual-level, buffering effects of horizontal cohesion were found for PTSD symptoms [B = −0.11, 95% CI (−0.18 to −0.04), p < 0.01] and depressive symptoms [B = −0.06, 95% CI (−0.10 to −0.01), p < 0.05]; while a buffering effect of vertical cohesion was observed for PTSD symptoms only [B = −0.03, 95% CI (−0.06 to −0.0001), p < 0.05]. At the unit-level, buffering effects of horizontal (but not vertical) cohesion were observed for PTSD symptoms [B = −0.91, 90% CI (−1.70 to −0.11), p = 0.06], depressive symptoms [B = −0.83, 90% CI (−1.24 to −0.41), p < 0.01], and suicidal ideation [B = −0.32, 90% CI (−0.62 to −0.01), p = 0.08].

Conclusions

Policies and interventions that enhance horizontal cohesion may protect combat-exposed units against post-deployment mental health problems. Efforts to support individual soldiers who report low levels of horizontal or vertical cohesion may also yield mental health benefits.

Keywords

Depressionmilitary personnelmultilevel analysispost-traumatic stress disorderprotective factorspsychological resiliencerisk factorssuicidal ideation
Type
Original Article
Information
Psychological Medicine , Volume 52 , Issue 1 , January 2022 , pp. 121 - 131
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Copyright
Copyright © The Author(s), 2020. Published by Cambridge University Press

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References

Anderson, L., Campbell-Sills, L., Ursano, R. J., Kessler, R. C., Sun, X., Heeringa, S. G., … Stein, M. B. (2019). Prospective associations of perceived unit cohesion with postdeployment mental health outcomes. Depression and Anxiety, 36, 511–521.10.1002/da.22884CrossRefGoogle ScholarPubMed
Armistead-Jehle, P., Johnston, S. L., Wade, N. G., & Ecklund, C. J. (2011). Posttraumatic stress in U.S. Marines: The role of unit cohesion and combat exposure. Journal of Counseling and Development, 89, 81–88.10.1002/j.1556-6678.2011.tb00063.xCrossRefGoogle Scholar
Bates, D. M., Mächler, M., Bolker, B., & Walker, S. (2015). Fitting linear mixed-effects models using lme4. Journal of Statistical Software, 67, 1–48.10.18637/jss.v067.i01CrossRefGoogle Scholar
Bliese, P. D., Adler, A. B., & Castro, C. A. (2011). Research-based preventive mental health care strategies in the military. In Adler, A. B., Bliese, P. D., & Castro, C. A. (Eds.), Deployment psychology: Evidence-based strategies to promote mental health in the military (pp. 103–124). Washington, DC: American Psychological Association.10.1037/12300-004CrossRefGoogle Scholar
Bliese, P. D., Maltarich, M. A., & Hendricks, J. L. (2018). Back to basics with mixed-effects models: Nine take-away points. Journal of Business and Psychology, 33, 1–23.CrossRefGoogle Scholar
Breslau, J., Setodji, C. M., & Vaughan, C. A. (2016). Is cohesion within military units associated with post-deployment behavioral and mental health outcomes? Journal of Affective Disorders, 198, 102–107.CrossRefGoogle ScholarPubMed
Brooks, S. K., & Greenberg, N. (2018). Non-deployment factors affecting psychological wellbeing in military personnel: Literature review. Journal of Mental Health, 27, 80–90.10.1080/09638237.2016.1276536CrossRefGoogle ScholarPubMed
Browne, T., Iversen, A., Hull, L., Workman, L., Barker, C., Horn, O., … Fear, N. T. (2008). How do experiences in Iraq affect alcohol use among male UK armed forces personnel? Occupational and Environmental Medicine, 65, 628–633.10.1136/oem.2007.036830CrossRefGoogle ScholarPubMed
Bryan, C. J., Griffith, J. E., Pace, B. T., Hinkson, K., Bryan, A. O., Clemans, T. A., & Imel, Z. E. (2015). Combat exposure and risk for suicidal thoughts and behaviors among military personnel and veterans: A systematic review and meta-analysis. Suicide and Life Threatening Behavior, 45, 633–649.10.1111/sltb.12163CrossRefGoogle ScholarPubMed
Campbell-Sills, L., Ursano, R. J., Kessler, R. C., Sun, X., Heeringa, S. G., Nock, M. K., … Stein, M. B. (2018). Prospective risk factors for post-deployment heavy drinking and alcohol or substance use disorder among US Army soldiers. Psychological Medicine, 48, 1624–1633.10.1017/S0033291717003105CrossRefGoogle ScholarPubMed
Carvalho, J. P., & Hopko, D. R. (2011). Behavioral theory of depression: Reinforcement as a mediating variable between avoidance and depression. Journal of Behavior Therapy and Experimental Psychiatry, 42, 154–162.10.1016/j.jbtep.2010.10.001CrossRefGoogle ScholarPubMed
Griffith, J. (2015). Cross (unit)-level effects of cohesion on relationships of suicide thoughts to combat exposure, postdeployment stressors, and postdeployment social support. Behavioral Medicine, 41, 98–106.10.1080/08964289.2014.987719CrossRefGoogle ScholarPubMed
Hines, L. A., Sundin, J., Rona, R. J., Wessely, S., & Fear, N. T. (2014). Posttraumatic stress disorder post Iraq and Afghanistan: Prevalence among military subgroups. Canadian Journal of Psychiatry, 59, 468–479.10.1177/070674371405900903CrossRefGoogle ScholarPubMed
Hofmann, D. A., & Gavin, M. B. (1998). Centering decisions in hierarchical linear models: Implications for research in organizations. Journal of Management, 24, 623–641.CrossRefGoogle Scholar
Hoge, C. W., Auchterlonie, J. L., & Milliken, C. S. (2006). Mental health problems, use of mental health services, and attrition from military service after returning from deployment to Iraq or Afghanistan. Journal of the American Medical Association, 295, 1023–1032.CrossRefGoogle ScholarPubMed
Hoge, C. W., Castro, C. A., Messer, S. C., McGurk, D., Cotting, D. I., & Koffman, R. L. (2004). Combat duty in Iraq and Afghanistan, mental health problems, and barriers to care. New England Journal of Medicine, 351, 13–22.10.1056/NEJMoa040603CrossRefGoogle ScholarPubMed
Hom, M. A., Stanley, I. H., Schneider, M. E., & Joiner, T. E. Jr. (2017). A systematic review of help-seeking and mental health service utilization among military service members. Clinical Psychology Review, 53, 59–78.CrossRefGoogle ScholarPubMed
Joint Mental Health Advisory Team 7 (J-MHAT 7). (2011). Joint Mental Health Advisory Team 7 (J-MHAT 7) Report. Retrieved from https://armymedicine.health.mil/Reports.Google Scholar
Jones, N., Seddon, R., Fear, N. T., McAllister, P., Wessely, S., & Greenberg, N. (2012). Leadership, cohesion, morale, and the mental health of UK Armed Forces in Afghanistan. Psychiatry, 75, 49–59.10.1521/psyc.2012.75.1.49CrossRefGoogle ScholarPubMed
Kanesarajah, J., Waller, M., Zheng, W. Y., & Dobson, A. J. (2016). Unit cohesion, traumatic exposure and mental health of military personnel. Occupational Medicine, 66, 308–315.10.1093/occmed/kqw009CrossRefGoogle ScholarPubMed
Keane, T. M., Marshall, A. D., & Taft, C. T. (2006). Posttraumatic stress disorder: Etiology, epidemiology, and treatment outcome. Annual Review of Clinical Psychology, 2, 161–197.10.1146/annurev.clinpsy.2.022305.095305CrossRefGoogle ScholarPubMed
Kessler, R. C., Colpe, L. J., Fullerton, C. S., Gebler, N., Naifeh, J. A., Nock, M. K., … Heeringa, S. G. (2013). Design of the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS). International Journal of Methods in Psychiatric Research, 22, 267–275.CrossRefGoogle Scholar
Kessler, R. C., Stein, M. B., Petukhova, M. V., Bliese, P., Bossarte, R. M., & Bromet, E. J., … Army STARRS Collaborators. (2017). Predicting suicides after outpatient mental health visits in the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS). Molecular Psychiatry, 22, 544–551.CrossRefGoogle Scholar
Kessler, R. C., & Ustun, T. B. (2004). The World Mental Health (WMH) survey initiative version of the World Health Organization (WHO) Composite International Diagnostic Interview (CIDI). International Journal of Methods in Psychiatric Research, 13, 93–121.CrossRefGoogle Scholar
King, L. A., King, D. W., Vogt, D. S., Knight, J., & Samper, R. E. (2006). Deployment Risk and Resilience Inventory: A collection of measures for studying deployment related experiences of military personnel and veterans. Military Psychology, 18, 89–120.CrossRefGoogle Scholar
Kroenke, K., Spitzer, R. L., & Williams, J. B. (2001). The PHQ-9: Validity of a brief depression severity measure. Journal of General Internal Medicine, 16, 606–613.CrossRefGoogle ScholarPubMed
Liu, R. T., Kleiman, E. M., Nestor, B. A., & Cheek, S. M. (2015). The hopelessness theory of depression: A quarter century in review. Clinical Psychology, 22, 345–365.Google Scholar
Markowitz, J. C., & Weissman, M. M. (2004). Interpersonal psychotherapy: Principles and applications. World Psychiatry, 3, 136–139.Google Scholar
Marroquin, B. (2011). Interpersonal emotion regulation as a mechanism of social support in depression. Clinical Psychology Review, 31, 1276–1290.10.1016/j.cpr.2011.09.005CrossRefGoogle ScholarPubMed
Mitchell, M. M., Gallaway, M. S., Millikan, A. M., & Bell, M. (2012). Interaction of combat exposure and unit cohesion in predicting suicide-related ideation among post-deployment soldiers. Suicide and Life Threatening Behavior, 42, 486–494.CrossRefGoogle ScholarPubMed
Nock, M. K., Deming, C. A., Fullerton, C. S., Gilman, S. E., Goldenberg, M., Kessler, R. C., … Ursano, R. J. (2013). Suicide among soldiers: A review of psychosocial risk and protective factors. Psychiatry, 76, 97–125.CrossRefGoogle ScholarPubMed
Panzarella, C., Alloy, L. B., & Whitehouse, W. G. (2006). Expanded hopelessness theory of depression: On the mechanisms by which social support protects against depression. Cognitive Therapy and Research, 30, 307–333.CrossRefGoogle Scholar
Pietrzak, R. H., Johnson, D. C., Goldstein, M. B., Malley, J. C., Rivers, A. J., Morgan, C. A., & Southwick, S. M. (2010). Psychosocial buffers of traumatic stress, depressive symptoms, and psychosocial difficulties in veterans of Operations Enduring Freedom and Iraqi Freedom: The role of resilience, unit support, and postdeployment social support. Journal of Affective Disorders, 120, 188–192.CrossRefGoogle ScholarPubMed
Pinheiro, J., Bates, D., DebRoy, S., & Sarkar, D., & R Core Team. (2019). nlme: Linear and nonlinear mixed effects models. R package version 3.1–141 [Computer software].Google Scholar
Posner, K., Brown, G. K., Stanley, B., Brent, D. A., Yershova, K. V., Oquendo, M. A., … Mann, J. J. (2011). The Columbia-Suicide Severity Rating Scale: Initial validity and internal consistency findings from three multisite studies with adolescents and adults. American Journal of Psychiatry, 168, 1266–1277.CrossRefGoogle ScholarPubMed
Raudenbush, S. W., & Bryk, A. S. (2002). Hierarchical linear models: Applications and data analysis methods. Thousand Oaks, CA: Sage.Google Scholar
Shaver, J. M. (2019). Interpreting interactions in linear fixed-effect regression models: When fixed-effect estimates are no longer within-effects. Strategy Science, 4, 25–40.CrossRefGoogle Scholar
Smith, T. C., Ryan, M. A., Wingard, D. L., Slymen, D. J., Sallis, J. F., Kritz-Silverstein, D., & The Millennium Cohort Study. (2008). New onset and persistent symptoms of post-traumatic stress disorder self-reported after deployment and combat exposures: Prospective population-based US military cohort study. BMJ, 336, 366–371.CrossRefGoogle ScholarPubMed
Ursano, R. J., Colpe, L. J., Heeringa, S. G., Kessler, R. C., Schoenbaum, M., & Stein, M. B., & Army STARRS Collaborators. (2014). The Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS). Psychiatry, 77, 107–119.CrossRefGoogle Scholar
Ursano, R. J., Kessler, R. C., Naifeh, J. A., Herberman Mash, H., Fullerton, C. S., Aliaga, P. A., … Stein, M. B. (2018). Associations of time-related deployment variables with risk of suicide attempt among soldiers: Results from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS). JAMA Psychiatry, 75, 596–604.CrossRefGoogle Scholar
Vogt, D. S., Proctor, S. P., King, D. W., King, L. A., & Vasterling, J. J. (2008). Validation of scales from the Deployment Risk and Resilience Inventory in a sample of Operation Iraqi Freedom veterans. Assessment, 15, 391–403.CrossRefGoogle Scholar
Weathers, F., Litz, B., Herman, D., Huska, J., & Keane, T. (1993). The PTSD Checklist (PCL): Reliability, validity, and diagnostic utility. Paper presented at the annual convention of the International Society for Traumatic Stress Studies: San Antonio, TX.Google Scholar
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