AUTHOR=Prieur Constance , Lhote Vincent , Marsaudon Antoine , Guillaume Stéphanie , Jusot Florence , Wittwer Jérôme , Dourgnon Paul 
  
TITLE=Post-Traumatic Stress Disorder Among Undocumented Immigrants. Evidence for the Premier-Pas Survey
  
JOURNAL=International Journal of Public Health
  
VOLUME=Volume 71 - 2026
  
YEAR=2026
  
URL=https://www.ssph-journal.org/journals/international-journal-of-public-health/articles/10.3389/ijph.2026.1608844
  
DOI=10.3389/ijph.2026.1608844
  
ISSN=1661-8564
  
ABSTRACT=ObjectivesUndocumented immigrants are a highly vulnerable population, frequently exposed to violence and trauma in their country of origin, along the migration journey, and in the host country. This study investigates which factors experienced before, during, and after migration influence the development of post-traumatic stress disorder (PTSD). It also investigates whether PTSD relates to high-risk health behaviors in France.MethodsWe relied on a survey representative of undocumented immigrants attending facilities providing assistance to vulnerable populations in Paris and Bordeaux (France). Analyses relied on several multivariate probit models (N = 1,060).ResultsOverall, 54.1% of respondents experienced at least one traumatic event, and 17.2% currently suffer from PTSD. Factors associated with an increase probability to develop PTSD are: coming to France for safety reasons (before migration), entering France without appropriate documentation (during migration), food insecurity and poor housing conditions (after migration). PTSD is also associated with an increase probability to engage in high-risk alcohol consumption.ConclusionAlthough pre-migration factors cannot be addressed by destination-country policies, our findings suggest that interventions targeting deprivation may help reducing PTSD and substance use among undocumented immigrants.