The cumulative contribution of direct and indirect traumas to the production of PTSD

Objective Posttraumatic Stress Disorder (PTSD) affects millions of people worldwide. While the relationship between direct exposure to traumatic events and PTSD is well-established, the influence of indirect trauma exposure on PTSD remains unclear. It is similarly unclear what role cumulative exposure to direct and indirect traumas play in the risk of PTSD. Methods The study uses data from the Houston Trauma and Recovery Study, conducted on 2020–2021, and involved a random sampling of 1,167 individuals residing in Houston during Hurricane Harvey in 2017. Participants were asked about their experiences related to both Hurricane Harvey and the subsequent COVID-19 pandemic. Exposures were categorized as direct or indirect traumas, in line with the criteria delineated in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Cumulative exposures were also calculated. Results Among participants, 12.6% were experiencing current PTSD. There were significant associations between both direct [OR = 3.18, 95% CI 1.85, 5.46] and indirect [OR = 1.91, 95% CI 1.05, 3.46] traumas related to Harvey, as well as direct [OR = 2.13, 95% CI 1.20, 3.77] and indirect [OR = 1.69, 95% CI 0.93, 3.09] traumas due to COVID and the risk of PTSD in fully adjusted models. Further, significant associations were found between the cumulative exposure to traumas from both Hurricane Harvey and COVID-19 and the risk of PTSD, considering both direct [OR = 2.53, 95% CI 1.36, 4.70] and indirect exposures [OR = 2.79, 95% CI 1.47, 5.28]. Conclusions Our study offers support for connections between exposure to both direct and indirect traumas stemming from large-scale disasters and PTSD. Moreover, we show that cumulative exposures to multiple large-scale events increase the risk of PTSD. This highlights the importance of the consideration of a range of exposures as risks for PTSD, particularly in a time of compounding disasters and broad population exposures to these events.