Correlates and prevalence of post-traumatic stress disorders in the São Paulo metropolitan area, Brazil.

Background: Post-traumatic stress disorder (PTSD) is a debilitating condition, which generates an extensive burden. We aimed to investigate in a huge metropolitan area, the prevalence of traumatic experiences, the development of PTSD, and its predictors.

Methods: Traumatic experiences and PTSD were assessed in 5037 adult individuals of the general population. Cross-tabulations method assessed the prevalence of traumatic events and PTSD. Logistic regression models investigated predictors of lifetime and 12-month odds of PTSD and the conditional probability of developing PTSD for specific traumas.

Results: Lifetime and 12-month diagnoses of PTSD were found in 3.2% and 1.6% of the sample. 'Witnessing anyone being injured or killed, or unexpectedly seeing a dead body' (35,7%) and 'being mugged or threatened with a weapon' (34.0%) were the two most reported traumas. The commonest events before PTSD onset were 'sudden unexpected death of a loved one' (34.0%), 'interpersonal violence' (31.0%), and 'threats to the physical integrity of others' (25.0%). Experiences related to "interpersonal violence" presented the highest conditional probability for PTSD (range 2.2-21.2%). Being 'sexually assaulted or molested' (21.2% total; 22.3% women; 0.0% men) and being 'raped' (18.8% total; 18.4% women; 20.1% men) were the two experiences with the highest odds for PTSD. While being female was a predictor of less exposure to any event (OR = 0.69), females were more prone to develop lifetime PTSD after exposure to an event (OR = 2.38).

Conclusion: Traumatic events are frequent in the general population and a small group of traumatic events accounts for most cases of subsequent PTSD.