Complex post-traumatic stress: widely varying estimates among displaced people

A disorder that goes beyond the core symptoms of post-traumatic stress

Complex post-traumatic stress disorder combines the core symptoms of post-traumatic stress with disturbances in self-organization: difficulties with emotional regulation, a negative self-concept and relationship difficulties.

Forcibly displaced populations are frequently exposed to severe, prolonged or repeated trauma that is difficult to escape. The review seeks to quantify how common this disorder is in these populations and to examine what this concept adds beyond post-traumatic stress.

A descriptive average, not a universal rate

The researchers searched five databases through January 2026. They included 20 studies, representing 17 independent samples and 12,504 participants, then used a random-effects meta-analysis.

The pooled prevalence is 20.9%, with a 95% confidence interval ranging from 12.6% to 32.6%. However, the authors retain this value as a descriptive summary of the included studies, not as an estimate applicable to all displaced people.

Reported prevalence estimates range from 3.0% to 74.6%. Heterogeneity between studies is very high, with an I² of 98.3%. This variability is a central finding: presenting only the average would obscure much of the information.

Recruitment and living conditions matter

Average estimates reach 10.6% in community-recruited samples, compared with 55.2% among people seeking care. These groups are therefore not interchangeable. Asylum seekers also show a higher prevalence than refugees, although no numerical estimate is specified in the abstract.

In four studies, post-migration difficulties, including legal insecurity, poverty and marginalization, are more strongly associated with disturbances in self-organization than with the core symptoms of post-traumatic stress. This finding suggests that current living conditions matter, but these associations alone do not demonstrate a causal link.

What we can take away

The key finding is not a single rate: the estimated frequency of complex post-traumatic stress varies widely depending on the populations studied and how they were recruited. Living conditions after displacement also deserve consideration, beyond earlier trauma.