What did this meta-study aim to achieve? 

This meta-analysis of 66 articles aimed to find the most accurate prevalence rates of anxiety, depression, and post-traumatic stress disorder (PTSD) among refugees who relocated to wealthy countries. Recent estimates for the prevalence of these disorders in refugees at the time of this meta-analysis were not available. Pooling the results of many studies was therefore needed to get an accurate picture of up-to-date prevalence estimates. In doing this, the analysis also aimed to understand both the potential causes of the differences in prevalence estimates (heterogeneity) between studies as well as the main factors responsible for anxiety, depression, and PTSD rates among refugees. 

Why is this issue important? 

The number of people in the world right now with refugee status is the highest it has been since World War Ⅱ. In addition to traumatic events often experienced in asylum seekers’ home countries and during their migration, refugees deal with high numbers of unemployment and loneliness once they have resettled in the new country. Identifying the causes of mental illness in refugees is crucial because of their high vulnerabilities. The more information that is known about mental illnesses in the refugee population, the more public health policies can be created and adapted to better support their needs once they are settled. 

How were the studies for the meta-analysis chosen? 

Using the information from 66 scientific articles, 150 prevalence estimates of depression, anxiety, and PTSD were selected. The articles that were included in the meta-analysis all utilized either semi-structured diagnostic interviews or questionnaires with validated cut-off scores to determine prevalence rates of anxiety, depression, and PTSD. All chosen articles also used their original data and figures. Finally, only refugees who had migrated into highly developed countries were included in any of the studies used by the meta-analysis. The studies used had to be conducted using the information from either the DSM-Ⅳ or DSM-Ⅴ. 

What prevalence rates for depression, anxiety, and PTSD were found? 

After analyzing the 150 prevalence rates from various studies, it was estimated that about 33% of the refugee population that has relocated to a highly developed country suffers from clinical PTSD and/or a depressive disorder. 10-20% of this refugee population is estimated to have a clinical anxiety disorder. The majority of the results from the studies were derived from self-report questionnaires, which were shown, on average, to produce slightly higher prevalence rates. Prevalences of all examined disorders (PTSD, depression, and anxiety) were significantly higher in refugees than in the general population. These results apply to children and adolescents as well as adults. Interestingly, the prevalence of these disorders was also significantly higher in refugees than among populations of adults living in war or high conflict countries. This result was not significant for children and adolescents. All results that were found apply to both males and females. 

Which factors predict depression, anxiety, and PTSD among refugees?

Multiple factors, such as familial separation, discrimination, unemployment, and prolonged asylum processes were shown to contribute to the prevalence of these mental disorders among refugees. Length of residency in the new country, the continent of origin, the continent of settlement, and the year the study was conducted were all found to have no statistically significant effect on the prevalence of mental disorders. Further, the prevalences did not change as a function of either age or gender. Notably, the factors that did raise the prevalence rates of these three disorders were characteristics of post-migration life. Since the length of residence was unrelated to mental illness prevalences, it may be that time on its own is not a sufficient factor for healing from the trauma of asylum-seeking or migration.

The refugee population is at a very high risk for developing PTSD, depression, and/or anxiety, even after they have been settled in a new country for many years. Therefore, it is of the utmost importance that future research is done on feasible prevention and treatment plans for mental illness in refugees, and action is taken by policymakers to implement these plans.