Complex post-traumatic stress disorder in refugees, asylum seekers, and internally displaced people: a systematic review and meta-analysis.

In 30 seconds

This systematic review and random-effects meta-analysis examined complex post-traumatic stress disorder (CPTSD) prevalence among refugees, asylum seekers, and internally displaced people. Twenty studies covering 17 independent samples (n = 12,504) reported prevalence ranging from 3.0% to 74.6%. The pooled estimate was 20.9% (95% CI [12.6%, 32.6%]), but heterogeneity was very high (I² = 98.3%) and the 95% prediction interval was [1.7%, 80.3%]. Prevalence estimates differed by recruitment context, averaging 10.6% in community samples and 55.2% in treatment-seeking samples; asylum seekers also had higher prevalence than refugees.

Key findings

• Pooled CPTSD prevalence was 20.9% (95% CI [12.6%, 32.6%]); the 95% prediction interval was [1.7%, 80.3%].
• Prevalence estimates averaged 10.6% in community-based samples and 55.2% in treatment-seeking samples.
• Between-study heterogeneity was very high (I² = 98.3%), with reported prevalence ranging from 3.0% to 74.6%.
• Across four studies, post-migration difficulties were more strongly associated with disturbances in self-organisation than with core PTSD symptoms.

Why it matters

The wide variation in estimates means the pooled prevalence should not be treated as a general rate for all forcibly displaced people. Differences by recruitment setting and displacement status, alongside associations between post-migration adversity and disturbances in self-organisation, highlight the importance of interpreting CPTSD findings in their social and sampling context.

What to keep in mind

Very high between-study heterogeneity and a limited, geographically uneven evidence base prevent global population-level inference.