Interaction of Val66Met BDNF and 5-HTTLPR polymorphisms with prevalence of post-earthquake 27-F PTSD in Chilean population

Natural disasters can have significant impacts on populations, including an increased risk of developing post-traumatic stress disorder (PTSD). This study aimed to investigate the prevalence of PTSD in individuals who had previously undergone structured psychiatric diagnostic interviews in the aftermath of the 27-F earthquake in Chile. The prevalence of post-earthquake PTSD was found to be 11.06%, with no significant difference from the reported prevalence of PTSD in those exposed to traumatic events. While studies have identified higher rates of PTSD in women, this study did not find any sex-related differences. However, a concomitant diagnosis of depressive episodes (DE) was significantly associated with an elevated risk of developing post-earthquake PTSD. Witnessing more than one critical traumatic event associated with the earthquake was also found to escalate the risk of developing earthquake-induced PTSD. The study also evaluated the potential influence of genetic factors on the risk of post-earthquake PTSD. The presence of BDNF and 5-HTTLPR genetic variants was assessed, and although studies have proposed that carriers of the Met allele are more susceptible to developing PTSD, this study did not identify a significant association between the Met allele and the incidence of post-earthquake PTSD. Similarly, while studies have suggested that individuals carrying at least one "S" allele of 5-HTTLPR are more susceptible to stress-related disorders, this study did not find a significant association between the LG and S alleles and the incidence of post-earthquake PTSD. The study highlights the need for clinical care to prioritize the detection and treatment of concomitant DE and the exposure to critical traumatic events in survivors of disasters. Early interventions can potentially mitigate the risk of developing post-disaster PTSD. Furthermore, the study suggests a need for a more comprehensive understanding of genetic predispositions to post-disaster PTSD, and future research is encouraged to explore other genetic variants that could influence the development of PTSD. Limitations of the study include the potential interference of different DE subtypes, the complexity of quantifying the degree of earthquake exposure experienced by each individual, and events entailing social disruption, such as looting, that can profoundly influence distress. These limitations highlight the need for further research to broaden the understanding of PTSD following disasters, potentially leading to more effective prevention and treatment strategies. In conclusion, this study emphasizes the multifaceted nature of PTSD and the significant role that critical traumatic experiences and concomitant depressive episodes play in the development of post-disaster PTSD. The study provides insights into potential areas for intervention and highlights the need for further research to better understand the relationship between genetic factors and post-disaster PTSD.