One would think that people with few friends and living in poverty are more at risk for PTSD than those with a strong support network and many resources.

And that’s true.

However, it is a different story when you look at the country-, rather than the individual level. Countries with more resources, such as the USA and the Netherlands, have higher levels of PTSD than countries with fewer resources (e.g. Colombia, South Africa).

This is the key finding of our latest study, which has just been published in the British Journal of Psychiatry. For the analyses, we made use of international data on trauma exposure, PTSD and country vulnerability. They had been collected in 24 different studies, published between 2005 and 2014.

The information on exposure and PTSD came from one, well-established and (evidently) widely used measure, the Composite International Diagnostic Interview. The country resources, or vulnerability, information came from the annual World Risk Report. It includes a mix of country characteristics, such as number of hospital beds, malnutrition, and gross domestic product per capita.

Both trauma exposure and vulnerability were major determinants of PTSD, but the latter in an unexpected way. While a higher percentage of trauma exposure in the country related to higher levels of PTSD, more vulnerability was associated with less PTSD.

Michel Dückers, the lead author of the study, calls it the “vulnerability paradox”. Continue reading →