Table 1: Cross-‐sectional and longitudinal studies examining prevalence of mental health problems and distress among soldiers who had been deployed to peacekeeping missions. Author Mission Sample Design Main conclusions a b US solders: 2,114 men, CS ; SR Yugoslavia, Longer deployments and first time deployments associated with increased Adler 2005 1,225 women c Hungary risk for PTSD and depressive symptoms in men but not women. d 1187 deployed vs. 669 CS; SR Probable PTSD : 11% for veterans vs. 3.9% for controls. PTSD symptoms Asmundson 2002 Multiple non-‐deployed Canadian had a negative influence on service members’ health through direct and veterans indirect paths (i.e., through depression, and alcohol use). CS; SR Probable PTSD: 16% in veterans vs. 9% in controls. Serving in Bosnia 145 UK service members Baggaley 1999 Bosnia associated with PTSD. No difference between groups on overall level of and 234 era controls psychopathology. 452 Italian service CS; SR Ballone 2000 Bosnia No increase in self-‐reported distress between cases and controls. members vs. 166 controls e L ; SR & Described stressors at each of the phases of deployment. Overall f Bartone 1998 Yugoslavia 128 US soldiers INT summarized stressors of peacekeeping as: 1) isolation, 2) ambiguity, 3) powerlessness, 4) boredom, and 5) threat and danger. CS; SR Prior to deployment, approximately 74% of reported a lifetime history of a Bolton 2001 Bosnia 2947 US soldiers potentially traumatic event and 6% had probable PTSD (witnessing injury was the most common traumatic event). CS; SR Individual’s perceptions of homecoming reception were positively Bolton 2002 Somalia 1,023 US soldiers associated with lower levels of PTSD symptoms CS; SR Self-‐disclosure of deployment stressors with family/friends were Bolton 2003 Somalia 426 US soldiers associated with lower PTSD symptoms. CS; SR PTSD symptom severity was associated with exposure to warzone stress. Bolton 2006 Somalia 522 US soldiers But, this association was modest. L; SR Pre-‐deployment personality traits (negativism and psychopathology) were 572 male Dutch service Bramsen 2000 Yugoslavia significantly associated with post-‐deployment PTSD symptoms even after members adjustment of number of stressors during deployment. US 161 soldiers mid-‐ L; SR Military hardiness was associated with being engaged in meaningful work Britt 2001 Bosnia deployment and post-‐ during deployment and deriving benefits from deployment. deployment L; SR Soldiers reporting higher levels of engagement in their work were less Britt 2003 Bosnia 1181 US soldiers likely to display distress in the context of higher work stress, less sleep and Author Mission Sample Design Main conclusions family stress. 40 Italian peacekeepers CS; SR Peacekeepers had significantly higher levels of anxiety. The two groups did Di Nicola 2007 Afghanistan vs. 120 era controls not differ on PTSD and depression symptoms. CS; SR Planful problem solving and seeking social support were associated with Dirkzwager 2003 Multiple 733 Dutch peacekeepers lower PTSD symptoms. CS; SR Probable PTSD prevalence 5.6%. Higher rates of PTSD symptoms among 3481 Dutch peacekeepers deployed to Bosnia in comparison to Cambodia. PTSD Dirkzwager 2005 Multiple peacekeepers associated with lower level of education, exposure to traumatic events, perceived meaninglessness of the mission, no control over situation. CS; SR Military hardiness (scale assessing military-‐specific commitment, Dolan 2006 Kosovo 629 US soldiers challenge, and control. Military hardiness moderated the impact of deployment stress on post-‐deployment depressive symptoms. 1132 male Canadian CS; SR PTSD and depressive symptoms were associated with health service use Elhai 2007 Multiple veterans intensity. CS; SR Two-‐thirds of those with PTSD sought help. Gender, lower military rank, Fikretoglu 2007, 2008, Multiple 8441 Canadian military lifetime trauma exposure, PTSD severity and comorbid depression were 2009 associated with service use. 1307 US men, 197 CS; SR Combat and sexual harassment associated with PTSD symptoms in both Fontana 2000 Somalia women men and women. 66 Australian L; INT PTSD symptoms were more severe among peacekeepers than Vietnam Forbes 2005 Africa peacekeepers and 63 veterans. At three months follow-‐up, no differences in treatment Vietnam controls outcomes. 1040 US soldiers, L; SR 6.5% of the sample had delayed onset Probable PTSD. War zone traumatic Gray 2004 Somalia 1 and 18 months after events exposure and perceived meaningfulness of the mission were deployment associated with symptom course. 1201 UK service CS; SR Talking about peacekeeping experiences was associated with lower Greenberg 2003 Bosnia members distress. Most peacekeepers make use of informal support networks. 1198 UK service CS; SR Deploying without an established peer group was not associated with Greenberg 2008 Multiple members PTSD symptoms. 25 Dutch peacekeepers CS; Int Neuropsychological testing revealed significantly lower levels of learning, with PTSD vs. to 25 Geuze 2009 Multiple immediate and delayed memory among PTSD veterans compared to those peacekeepers without without PTSD. PTSD Author Mission Sample Design Main conclusions Western 119 UN service members CS; SR 21% reported moderate levels of stress. Distress due to climate Han 2001 Sahara Desert from 23 countries adaptation, homesickness and interpersonal conflicts. 2 049 UK service CS; SR Highest level of PTSD symptoms among Gulf and Bosnia Veterans (13.2%). members vs. 1785 era Hotopf 2003a,b Bosnia Overall no increase in risk of PTSD symptoms among service members controls vs. 570 Gulf & deployed only to Bosnia (4.4%) vs. controls (4.5%), Bosnia veterans L; SR Self-‐perceived job control and active coping style impacted on the level of Ippolito 2005 Kosovo 638 US service members psychological distress. 1,086 Swedish service CS; SR No difference in psychiatric morbidity. Combat veterans more prone to Kettner 1972 Congo members, and, 1,242 accidents. controls 1046 Dutch CS; SR Dutch peacekeepers do not have higher rates of psychological distress Kllaassens 2008 Multiple peacekeeping veterans than the Dutch general population 10-‐25 years post-‐deployment. L; SR Baseline trait anxiety and insomnia predicted postdeployment Larsson 2008 Kosovo 44 Swedish peacekeepers posttraumatic symptoms. CS; SR Probable PTSD 8%. War zone stressors and negative aspects of Litz 1997a,b 3,461 US service peacekeeping predicted PTSD. Experiencing the military mission as Somalia Orsillo 1998 members rewarding/positive protected against PTSD. Military pride and cohesion are associated with lower distress L; SR Self-‐reported anxiety and distress was highest at pre-‐deployment and at Multiple MacDonald 1998, 277 New Zealand service the follow-‐up period in comparison with during deployment. Self-‐ missions 1999 members reported depression was highest at mid-‐deployment and 6 months follow-‐ 1992 up. 203 US service members L; SR Exposure to traumatic events associated with post-‐deployment PTSD Maguen 2004 Kosovo symptoms and depressive symptoms, but not problem drinking. Kosovo, 203 Kosovo personnel, L; SR Following deployment, 5%-‐9% of peacekeepers reported need for mental Maguen 2006 Bosnia 105 Bosnia reservists health treatment. Norwegian service CS; SR Service members that had prematurely been repatriated had the highest members – 888 veterans, levels of probable PTSD (16% vs. 5% in veterans). Level of stress during Mehlum 2002 Lebanon 323 repatriated, 485 service, perceived lack of meaningfulness of the mission, and stressful life controls events after the service were associated with probable PTSD. South 888 Norwegian service CS; SR 44% of service members reported increased alcohol consumption during Mehlum 1999 Lebanon members deployment. Exposure to combat exposure was associated with self-‐ Author Mission Sample Design Main conclusions medication with alcohol. 211 male Norwegian CS; SR UN observers had significantly elevated levels of distress and PTSD Mehlum 2006 Lebanon peacekeepers, 187 symptoms than peacekeepers. Norwegian observers L; SR No significant change on level of mental distress over time. Exposure to 316 Swedish Service Michel 2003 Bosnia traumatic events during deployment and post-‐deployment stressful members events associated with distress. L; SR 9.5% of the cohort met criteria for at least one probable personality 516 Swedish service disorder. The presence of a probable personality disorder at baseline was Michel 2005 Bosnia members associated with increased distress at one year follow-‐up, greater likelihood of reporting traumatic events during deployment. 130 Canadian veterans CS; INT The association between PTSD and pain was fully mediated by comorbid Poundja 2006 Multiple attending clinic depression. CS; SR Probable PTSD and depression higher among those with multiple deployments compared to those with one deployment and no Richardson 2006, 1,016 Canadian male Multiple deployments. Younger age, and not being married was associated with 2007 service members PTSD. Probable PTSD was associated with increased medical and specialist care utilization. 125 Canadian soldiers CS; INT PTSD and depression symptom severity were associate with lower quality Richardson 2008 Multiple attending clinic of life. CS; INT Exposure to peacekeeping operations, combat exposure and witnessing 8,441 Canadian service atrocities were associated with an increased likelihood of PTSD and other Sareen 2007, 2008 Multiple members (population-‐ mental disorder. Approximately 20% of cases of PTSD were attributable to based sample) peacekeeping operations. CS; SR Mental health condition remained stable before, during and after 339 Self-‐Defense Force Sawamura 2008 Golan Heights deployment with little variation in mental health conditions influenced by members deployment period. CS; SR Veterans with comorbid Probable PTSD and depression used more health 473 Canadian Stapleton 2006 Multiple care resources in the past year than did those with either PTSD or peacekeeping veterans depression alone. L; SR Baseline negative affect traits also appear to interact with the number of 138 male Brazilian Souza 2008 Haiti stressful situations experienced during deployment to increase the service members likelihood of post-‐deployment self-‐reported PTSD symptoms. Author Mission Sample Design Main conclusions CS; SR The majority of stress was perceived to be due to frustrations with the Multiple Thomas 2006 342 UK service members occupational role of being a peacekeeper, although many peacekeepers found their role fulfilling. UK service members: CS; SR Although Gulf war veterans were significantly more likely to be distressed 3284 Gulf war veterans, compared to Bosnia peacekeepers and controls, Bosnia peacekeepers did Unwin 1999 Bosnia 1815 Bosnia veterans, not have an increased risk of probable PTSD or GHQ caseness compared 2408 controls to controls 117 Australian soldiers CS; SR Self-‐reported distress increased in veterans compared to controls. Ward 1997 Somalia and 77 controls a b c CS-‐ Cross-‐sectional design, SR-‐ Main outcomes are based on self-‐report measures that are not designed for delineating diagnosis, PTSD-‐ Posttraumatic Stress d e f Disorder, Probable PTSD – High likelihood for PTSD based on self-‐report measures; L-‐ Longitudinal design; INT-‐ Interview based assessment of mental disorders.