Migration is not an event, but an interactive process whereby individuals on the move make decisions in their social and political contexts. As such, one expects migrant mental health to change over time. To examine this relationship, we conducted a meta-analysis, the first to our knowledge, to identify the impact of migration phase and migration type on the prevalence of mental health in migrant populations. We searched PubMed, PsycInfo, and Embase for studies published between January 1, 2010, and January 1, 2020 (Prospero ID: 192751). We included studies with international migrants reporting prevalence rates for post-traumatic stress disorder (PTSD), depression, and/or anxiety. The authors extracted data from eligible studies and tabulated mental health prevalence rates, relevant migration condition (e.g., migration type or phase), and methods (e.g., sample size).

Full text review resulted in n = 269 manuscripts included in the meta-analysis examining PTSD (n = 149), depression (n = 218), and anxiety (n = 104). Overall prevalence was estimated for PTSD (30.54 %, I² = 98.94 %, Q = 10,443.6), depression (28.57 %, I² = 99.17 %, Q = 13,844.34), and anxiety (25.30 %, I² = 99.2 %, Q = 10,416.20). We also estimated the effect of methodological and migration factors on prevalence in PTSD, depression, and anxiety. Our findings reveal increased prevalence of mental health due to forced migration and being in the journey phase of migration, even when accounting for the influence of methods.