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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: [email protected]
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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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