The study Holocaust exposure induced intergenerational effects on FKBP5 methylation by Yehuda (2016) investigates whether traumatic experiences from the Holocaust can leave biological traces that are visible in subsequent generations. The researchers focused on the FKBP5 gene, which is involved in the regulation of the stress hormone system (the HPA axis). Changes in the regulation of this gene can influence how the body copes with stress.

The study compared three groups: Holocaust survivors, their adult children, and a control group without direct Holocaust exposure. In both survivors and their descendants, the researchers found changes in DNA methylation of the FKBP5 gene. Methylation is an epigenetic process that determines how active a gene is without altering the genetic code itself. Notably, the methylation patterns in parents and children were not identical, but were clearly correlated. This points to a form of intergenerational transmission of stress-related biological changes.

The results suggest that extreme traumatic experiences can have long-lasting effects on stress regulation, and that these effects remain partially visible in the next generation. The study does not demonstrate deterministic transmission of trauma, but rather an increased sensitivity of the stress system. According to the authors, this may contribute to greater vulnerability to stress-related complaints, depending on later life circumstances and resilience factors.

Importantly, the researchers emphasize that epigenetic changes remain modifiable. Environmental factors, therapy, and social context can reshape the regulation of the stress system. The study thus provides a biologically substantiated indication that intergenerational trauma can have an impact not only psychologically but also physically, while simultaneously leaving room for recovery and plasticity.