A vulnerability paradox in the cross-national prevalence of post-traumatic stress disorder

Br J Psychiatry. 2016 Oct;209(4):300-305. doi: 10.1192/bjp.bp.115.176628. Epub 2016 Jul 21.


Background: Determinants of cross-national differences in the prevalence of mental illness are poorly understood.

Aims: To test whether national post-traumatic stress disorder (PTSD) rates can be explained by (a) rates of exposure to trauma and (b) countries' overall cultural and socioeconomic vulnerability to adversity.

Method: We collected general population studies on lifetime PTSD and trauma exposure, measured using the WHO Composite International Diagnostic Interview (DSM-IV). PTSD prevalence was identified for 24 countries (86 687 respondents) and exposure for 16 countries (53 038 respondents). PTSD was predicted using exposure and vulnerability data.

Results: PTSD is related positively to exposure but negatively to country vulnerability. Together, exposure, vulnerability and their interaction explain approximately 75% of variance in the national prevalence of PTSD.

Conclusions: Contrary to expectations based on individual risk factors, we identified a paradox whereby greater country vulnerability is associated with a decreased, rather than increased, risk of PTSD for its citizens.

MeSH terms

  • Culture
  • Exposure to Violence / ethnology
  • Exposure to Violence / statistics & numerical data*
  • Global Health / ethnology
  • Global Health / statistics & numerical data*
  • Humans
  • Prevalence
  • Psychological Trauma / epidemiology*
  • Psychological Trauma / ethnology
  • Risk Factors
  • Stress Disorders, Post-Traumatic / epidemiology*
  • Stress Disorders, Post-Traumatic / ethnology