What if the pain of trauma doesn't end with the person who experienced it? A new review of existing research suggests that severe stress—whether a single acute event or prolonged hardship—can leave molecular marks on the body, a process known as epigenetic change. These changes most consistently appear in the biological pathways that govern how we handle stress, how our immune system responds, how our brain develops, and how our metabolism works.
The review looked at how different types of trauma might leave different biological signatures. It found that a single traumatic event is often linked to changes in stress and inflammatory signals that could affect development. In contrast, chronic or complex trauma appears tied to broader, cumulative adaptations across stress-regulatory, metabolic, and brain development systems. For the children and grandchildren of those who experienced trauma, the review notes a pattern of increased vulnerability to anxiety, depression, stress-related disorders, and some chronic health conditions.
It's crucial to understand what this review does and does not tell us. The researchers are piecing together a complex puzzle from many small, varied studies. The science is still emerging, and interpretation is limited. Studies often had small groups of people, used different definitions of trauma, and lacked long-term, multi-generational data. This means we cannot say these biological changes cause specific outcomes in offspring. Instead, the work points to the importance of considering both biological and psychological factors when supporting families affected by trauma.
