Strengths and limitation
We estimated the absolute global number of war survivors with PTSD and/or MD by conducting an up-to-date and comprehensive systematic literature search. We maximised validity of extrapolations by only including interview-based epidemiological data from random general population samples. The extrapolations to absolute numbers may enable professionals from various disciplines to better grasp the burden of PTSD and MD on survivors of war and guide decision making to ultimately improve mental health of survivors.
Our study also has several limitations. The meta-analyses relied on only 41 surveys. This primarily reflects the current state of literature on war survivors that has mostly focused on refugees or other special war-surviving populations rather than general populations.29 In fact, the current literature base on interview-based randomly sampled surveys covers only 12 countries (and Palestine) and for the remaining 30 war-affected countries such samples are currently lacking. Therefore, our summary of the available literature might not be generalisable to countries with lacking data. On the notion of generalisability to countries with lacking data, it is worthwhile to check whether countries with available data may differ from countries without such data in terms of war-intensity. As can be seen in table 1, countries with available data bewailed on average 17 813 war-related deaths from 1989 to 2019 (SD=18 807) which translates into 99.48 war-related deaths per 100.000 population (SD=112.16). Whereas countries with missing data on average bewailed 40 042 (SD=71 980) or 183.17 per 100.000 population (SD=339.65). Across all 43 war-afflicted countries, an average of 33 322 (SD=61 593) individuals or 155.97 per 100.000 (SD=288.95) died due to war events. This demonstrates that the war-afflicted countries with available data are somewhat below average in terms of war-intensity. The performed moderator analyses did not yield significant differences in prevalence rates across 12 war-affected countries (plus Palestine) despite varying degrees of war-intensity and war-length (see online supplemental eTable 2). This finding may be unexpected, since higher intensity of trauma has been shown to relate to higher risk and prevalences of PTSD generally30 and also in the context of war trauma31 and genocide such as the Holocaust.32 Therefore, the results of this moderator analysis should be interpreted with caution as a dose–response relationship between war intensity and prevalences of trauma-related disorders appears plausible.31
Also related to the issue of limited data and generalisability, extrapolative accuracy is naturally restrained. Due to the general scarcity of data, we had to rely on pooled prevalences of PTSD and MD for extrapolations. In the light of varying degrees of war intensity and lengths as well as more general country-specific differences, such an approach is limited. However, the CIs for the pooled PTSD and MD prevalences were fairly narrow (22.17% to 31.10% and 18.55% to 28.42%, respectively) indicating fairly similar prevalences of PTSD and MD across the included surveys from 12 war-affected countries (plus Palestine) from three continents. Similarly, the moderator analysis on pooled prevalences by continent did not yield significant differences in PTSD prevalences across the three war-afflicted continents (ie, Africa, Asia and Europe). Surveys on MD were too scarce to allow for this moderator analysis. As more data accumulates, more fine-grained meta-analyses and, consequently, more fine-grained extrapolations will become possible.
Another potential limitation is that the current literature base exclusively covers cross-sectional surveys and lacks longitudinal data on remission from PTSD and MD. In their summary of the World Mental Health (WMH) Surveys, Kessler et al reported that remission of war-related PTSD would steeply increase about 6 years after exposure. The remission rate was reported to rise from about 20% at 5 years after war to about 70% at 6 years after war.33 In our review, the mean time between war and the assessment of disorders across all included surveys was 6.88 years. In our moderator analyses (see online supplemental eTable 2), the number of years between the end of the (last) war and the conduct of the survey was not found to be related to prevalence rates. This finding is at odds with previous research as illustrated by the above-mentioned summary of the WMH surveys. Yet, several factors might explain why remission rates may be dampened in post-war settings. Besides war-trauma, non-war-related traumatic experiences and difficult socioeconomic conditions may also influence the development and maintenance of PTSD and MD.34 35 Socioeconomic risk factors are more prevalent in LMICs with a history of war as compared with the countries included in the WHM surveys which were mostly high-income countries. Furthermore, individuals with mental disorders in LMICs are less likely to receive appropriate healthcare,36–38 and PTSD as well as MD, if left untreated, may follow a chronic course.39 40 However, while remission rates post-conflict might be dampened in war-ridden LMICs for various reasons, a degree of remission is still to be expected particularly over several decades as illustrated by long-term epidemiological data on WWII survivors.41–43 Therefore, null findings more probably boil down to a lack of longer-term data rather than lacking remissions per se.
Another potential limitation concerns heterogeneity in outcomes based on different nosology. We included surveys that conducted diagnostic interviews based on any ICD or DSM iteration, which use different criteria for defining PTSD and MD. Finally, this study estimates the disease burden for PTSD. Since the GBD 2019 does not report on PTSD DALYs separately, all anxiety disorder DALYs had to be used. The presented estimate, therefore, may overestimate or underestimate the PTSD-associated DALYs. The GBD study has already announced that it will report data on PTSD separately in coming iterations, which will allow for more accurate extrapolations.
Comparison with the literature
The pooled PTSD and MD prevalences are slightly lower than reported prevalences in most meta-analyses on these conditions in war-surviving populations (ie, ≥30%).3 4 29 In our previous meta-analyses, we found similarly high prevalences (ie, 24%–26% for PTSD and 23%–27% for MD).2 6 However, recent estimates by the WHO are considerably lower with 15.3% for PTSD and 10.8% for MD.1 As mentioned before, all previous meta-analyses partly or exclusively involved specific populations (eg, refugees, bereaved individuals) and precluded extrapolations to general war-surviving. Furthermore, related meta-analyses included self-report-based data.1 Self-report-based measures of PTSD (eg, PTSD CheckList – Civilian Version) and MD (eg, Patient Health Questionnaire – 9) either are not validated for LMICs or have poor psychometric properties in LMICs.44 To our knowledge, we performed the first meta-analysis that exclusively included representative interview-based data and, therefore, allowed for more valid extrapolations. We aimed at estimating the absolute prevalence and disease burden of PTSD and MD in war-afflicted countries, irrespective of assumptions about their aetiology. The elevated prevalences of PTSD and MD in war-surviving populations are not to be mistaken as solely caused by war-related trauma. The aetiologies of PTSD and MD are complex and, besides war experiences, non-war-related traumatic experiences, psychological stressors and aversive social conditions can play a role in the development and maintenance of PTSD and MD. However, independently of the precise aetiology of the disorders, the reported prevalences reflect the extent of the total burden and the need for help due to PTSD and MD in war-surviving populations.
Clinical, policy and research implications
In theory, effective psychological interventions for both youth and adult survivors of mass conflict do exist.38 45 However, most LMICs lack the resources in terms of both funding and qualified staff to provide evidence-based psychological treatments for all affected war survivors.36 37 46 While the allocation of financial and human resources for mental healthcare should surely increase,36 47 other approaches than specialised treatments are needed to address the mental health needs of survivors of war. For this, mental healthcare should be as much as possible integrated into the overall response to healthcare following wars. This may include strengthening of primary care to address mental disorders in primary care, task-sharing of psychosocial interventions with trained non-professional individuals, involving families and informal carers, using digital platforms to facilitate the delivery of interventions, and the development and implementation of community-based interventions.48–52 All these options may benefit from more systematic research to inform public health policies and practice.