The prevalence of mental illness in refugees and asylum seekers: A systematic review and meta-analysis

Abstract

Background: Globally, the number of refugees and asylum seekers has reached record highs. Past research in refugee mental health has reported wide variation in mental illness prevalence data, partially attributable to methodological limitations. This systematic review aims to summarise the current body of evidence for the prevalence of mental illness in global refugee populations and overcome methodological limitations of individual studies.

Methods and findings: A comprehensive search of electronic databases was undertaken from 1 January 2003 to 4 February 2020 (MEDLINE, MEDLINE In-Process, EBM Reviews, Embase, PsycINFO, CINAHL, PILOTS, Web of Science). Quantitative studies were included if diagnosis of mental illness involved a clinical interview and use of a validated assessment measure and reported at least 50 participants. Study quality was assessed using a descriptive approach based on a template according to study design (modified Newcastle-Ottawa Scale). Random-effects models, based on inverse variance weights, were conducted. Subgroup analyses were performed for sex, sample size, displacement duration, visa status, country of origin, current residence, type of interview (interpreter-assisted or native language), and diagnostic measure. The systematic review was registered with PROSPERO (CRD) 42016046349. The search yielded a result of 21,842 records. Twenty-six studies, which included one randomised controlled trial and 25 observational studies, provided results for 5,143 adult refugees and asylum seekers. Studies were undertaken across 15 countries: Australia (652 refugees), Austria (150), China (65), Germany (1,104), Italy (297), Lebanon (646), Nepal (574), Norway (64), South Korea (200), Sweden (86), Switzerland (164), Turkey (238), Uganda (77), United Kingdom (420), and the United States of America (406). The prevalence of posttraumatic stress disorder (PTSD) was 31.46% (95% CI 24.43-38.5), the prevalence of depression was 31.5% (95% CI 22.64-40.38), the prevalence of anxiety disorders was 11% (95% CI 6.75-15.43), and the prevalence of psychosis was 1.51% (95% CI 0.63-2.40). A limitation of the study is that substantial heterogeneity was present in the prevalence estimates of PTSD, depression, and anxiety, and limited covariates were reported in the included studies.

Conclusions: This comprehensive review generates current prevalence estimates for not only PTSD but also depression, anxiety, and psychosis. Refugees and asylum seekers have high and persistent rates of PTSD and depression, and the results of this review highlight the need for ongoing, long-term mental health care beyond the initial period of resettlement.

Fig 1. Search results and selection of studies reporting prevalence of mental illness among refugees and asylum seekers.

Fig 2. Prevalence of PTSD in refugees and asylum seekers.

*Study with sample size of ≥200. Horizontal lines indicate 95% CIs; horizontal points of the open diamond are the limits of the overall 95% CIs; and the red dashed line shows the position of the overall prevalence. AF, Afghanistan; AZR, Azerbaijan; CI, confidence interval; Frmr Yug, former Yugoslavia; ME, Middle East; PTSD, posttraumatic stress disorder; W Afr, West Africa.

Fig 3. Prevalence of PTSD by various study characteristics.

p-Values derived from random-effects models; horizontal lines indicate 95% CIs. CAPS, Clinician Administered PTSD Scale; CI, confidence interval; M.I.N.I., the Mini-International Neuropsychiatric Interview; PTSD, posttraumatic stress disorder; SCID, Structured Clinical Interview for DSM; WHO-CIDI, World Health Organization–Composite International Diagnostic Interview.

Fig 4. Prevalence of depression in refugees and asylum seekers.

*Study with sample size of ≥200. Horizontal lines indicate 95% CIs; horizontal points of the open diamond are the limits of the overall 95% CIs; and the red dashed line shows the position of the overall prevalence. AZR, Azerbaijan; CI, confidence interval; Frmr Yug, former Yugoslavia; ME, Middle East.

Fig 5. Prevalence of depression by various study characteristics.

p-Values derived from random-effects models; horizontal lines indicate 95% CI. Subgroup analysis for sex could not be conducted, owing to a lack of reported data. CI, confidence interval; M.I.N.I., the Mini-International Neuropsychiatric Interview; SCID, Structured Clinical Interview for DSM; WHO-CIDI, World Health Organization–Composite International Diagnostic Interview.

Fig 6. Prevalence of anxiety in refugees and asylum seekers.

*Study with sample size of ≥200. Horizontal lines indicate 95% CIs; horizontal points of the open diamond are the limits of the overall 95% CIs; and the red dashed line shows the position of the overall prevalence. AZR, Azerbaijan; CI, confidence interval; Frmr Yug, former Yugoslavia; ME, Middle East.

Fig 7. Prevalence of anxiety by various study characteristics.

p-Values are derived from random-effects models; horizontal lines indicate 95% CI. Subgroup analysis for sex could not be conducted, owing to a lack of reported data. Subgroup analysis for diagnostic measure could not be conducted, owing to insufficient studies for each measure. CI, confidence interval.

Fig 8. Prevalence of psychosis in refugees and asylum seekers.

Horizontal lines indicate 95% CIs. Horizontal points of the open diamond are the limits of the overall 95% CIs; and the red dashed line shows the position of the overall prevalence. AZR, Azerbaijan; CI, confidence interval; Frmr Yug, former Yugoslavia; ME, Middle East.