Background: Elevated prevalences of post-traumatic stress disorder (PTSD) and major depression (MD) have been reported in populations exposed to war. However, no global estimates of war survivors suffering from PTSD and/or MD in absolute numbers have been reported. Objective: We made the first attempt to estimate in absolute numbers how many adult war survivors globally may suffer PTSD and/or MD, which should inform local and global mental health programmes. Method: Drawing on the Uppsala Conflict Database, we reviewed all countries that suffered at least one war within their own territory between 1989 and 2015 (time span chosen on availability of geo-referenced data and population estimates). We then conducted a metaanalysis of current randomized epidemiological surveys on prevalence of PTSD and/or MD among war survivors. Finally, we extrapolated our results from the meta-analysis on the global population of adult war survivors by means of using general population data from the United Nations. Results: We estimate that about 1.45 billion individuals worldwide have experienced war between 1989 and 2015 and were still alive in 2015, including one billion adults. On the basis of our meta-analysis, we estimate that about 354 million adult war survivors suffer from PTSD and/or MD. Of these, about 117 million suffer from comorbid PTSD and MD. Conclusions: Based on the slim available evidence base, the global number of adult war survivors suffering PTSD and/or MD is vast. Most war survivors live in low-to-middle income countries with limited means to handle the enormous mental health burden. Since representative high quality data is lacking from most of these countries, our results contain a large margin of uncertainty and should be interpreted with caution.

ObjectiveExtensive research has demonstrated high prevalences of post-traumatic stress disorder (PTSD) and major depression (MD) in war-surviving populations. However, absolute estimates are lacking, which may additionally inform policy making, research and healthcare. We aimed at estimating the absolute global prevalence and disease burden of adult survivors of recent wars (1989–2019) affected by PTSD and/or MD.MethodsWe conducted a systematic literature search and meta-analysis of interview-based epidemiological surveys assessing the prevalence of PTSD and/or MD in representative samples from countries with a recent war history (1989–2019). Drawing on the war definition and geo-referenced data of the Uppsala Conflict Database Programme and population estimates of the United Nations for 2019, we extrapolated the meta-analytic results to absolute global numbers of affected people. Drawing on disability-adjusted life years (DALYs) data of the Global Burden of Diseases Study 2019, we further calculated the PTSD-associated and MD-associated DALYs.ResultsTwenty-two surveys (N=15 420) for PTSD, 13 surveys for MD (N=9836) and six surveys on the comorbidity of PTSD and MD (N=1131) were included. Random effects meta-analyses yielded point prevalences of 26.51% for PTSD and 23.31% for MD. Of those affected by PTSD, 55.26% presented with comorbid MD. Prevalence rates were not significantly associated with war intensity and length, time since war, response rate or survey quality. The extrapolation yielded 316 million adult war-survivors globally who suffered from PTSD and/or MD in 2019. War-survivors were almost exclusively living in low/middle-income countries (LMICs) and carried a burden of 3 105 387 and 4 083 950 DALYs associated with PTSD and MD, respectively.ConclusionsSince LMICs lack sufficient funding and qualified professionals to provide evidence-based psychological treatments for such large numbers of affected people, alternative and scalable strategies using existing resources in primary care and communities are required. Research is required to assist upscaling.

BackgroundThe imperative for physical distancing (mostly referred to as social distancing) during COVID-19 pandemic may deteriorate physical and mental health. We aimed at summarising the strength of evidence in the published literature on the association of physical and mental health with social connection via social isolation, living alone and loneliness.MethodsWe conducted a systematic search in April 2020 to identify meta-analyses using the Medline, PsycINFO and Web of Science databases. The search strategy included terms of social isolation, loneliness, living alone and meta-analysis. Eligible meta-analyses needed to report any sort of association between an indicator of social connection and any physical or mental health outcome. The findings were summarised in a narrative synthesis.ResultsTwenty-five meta-analyses met our criteria, of which 10 focused on physical health and 15 on mental health outcomes. The results suggest that lack of social connection is associated with chronic physical symptoms, frailty, coronary heart disease, malnutrition, hospital readmission, reduced vaccine uptake, early mortality, depression, social anxiety, psychosis, cognitive impairment in later life and suicidal ideation.ConclusionsThe existing evidence clearly indicates that social connection is associated with a range of poor physical and mental health outcomes. A potential negative impact on these outcomes needs to be considered in future decisions on physical distancing measures.

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Comparative thinking is ubiquitous in human cognition. Empirical evidence is accumulating that PTSD symptomatology is linked to various changes in social, temporal and counterfactual comparative thinking. However, no systematic review and meta-analysis in this line of research have been conducted to this date. We searched titles, abstracts and subject terms of electronic records in PsycInfo and Medline from inception to January 2019 with various search terms for social, temporal and counterfactual comparative thinking as well as PTSD. Journal articles were included if they reported a quantitative association between PTSD and social, temporal and/or counterfactual comparative thinking in trauma-exposed clinical or sub-clinical samples. A total of 36 publications were included in the qualitative synthesis. The number of publications on the association between PTSD and social and temporal comparative thinking was too scarce to warrant a meta-analytic review. A narrative review of available literature suggests that PTSD is associated with distortions in social and temporal comparative thinking. A meta-analysis of 24 independent samples (n = 4423) assessing the association between PTSD and the frequency of counterfactual comparative thinking yielded a medium to large positive association of r =.464 (p <.001, 95% CI =.404; .520). Higher study quality was associated with higher magnitude of association in a metaregression. Most studies collected data cross-sectionally, precluding conclusions regarding causality. Overall, study quality was found to be moderate. More longitudinal and experimental research with validated comparative thinking measures in clinical samples is needed to acquire a more sophisticated understanding of the role of comparative cognitions in the aetiology and maintenance of PTSD. Comparative thinking might be a fruitful avenue for a better understanding of posttraumatic reactions and improving treatment.