Gene expression and epigenetic changes in post-traumatic stress disorder, depression, and anxiety in first responders: A systematic review

Abstract

Objective

Police, firefighters, dispatchers, and emergency medical technicians—collectively known as first responders—are a unique population frequently exposed to chronic, traumatic incidents. This exposure results in a high prevalence of PTSD, depression, and anxiety, posing a substantial public health concern. Genetic predispositions and epigenetic modifications that regulate gene expression are significant contributors to trauma-related pathologies. This systematic review aims to summarize current data on epigenetic and gene expression changes in first responders related to three post-trauma pathologies: PTSD, depression, and anxiety. We also explore genetic pathways across these disorders to identify potential commonalities and therapeutic targets.

Methods

Following PRISMA guidelines, databases were searched from July to October 2023, yielding 1103 studies, 12 of which met the inclusion criteria (total N = 6943).

Results

Of the included studies, 11 examined PTSD, consistently implicating stress-response genes, such as those in the hypothalamic–pituitary–adrenal axis (e.g., FKBP5, NR3C1), and genes related to inflammation and immune responses. Three studies focused on depression-related genetic biomarkers but reported no significant genome-wide methylation differences between responders with current versus no major depressive disorder (MDD). No studies addressed epigenetic or gene expression changes linked to anxiety.

Conclusion

This review identified novel genes and pathways related to trauma as potential targets for future research and pharmacological therapy. It also highlights a significant gap in the literature, emphasizing the need for broader research to investigate the genetic underpinnings of trauma exposure in first responders, aiming to identify relevant pathways and therapeutic targets.