When Trauma Crosses Generations: Mechanisms, Clinical Patterns and Therapeutic Implications of Transgenerational Trauma—A Systematic Review

BACKGROUND: Transgenerational trauma (TT)/Intergenerational trauma (IT) is the transmission of the effects of traumatic experiences of parents to their children, who have not themselves experienced traumatic events. This transmission occurs through neurobiological and metabolic changes and the environment in which they were raised. METHODS: A systematic review was conducted in accordance with the PRISMA 2020 guidelines. PubMed and Google Scholar databases were searched from 2005 to 2025. Studies focusing on adult offspring, exposure to ancestral trauma, biological markers (DNA methylation, cortisol), and psychological outcomes were included. RESULTS: gene and accelerated biological aging (GrimAge) in offspring; role of parental reflective functioning (PRF) and impaired mentalization as major psychological channels of trauma transmission; and evidence confirming the impact on three generations, manifested by treatment-resistant depressive disorders, anxiety, and neuroendocrine dysregulation (low cortisol levels). CONCLUSIONS: This article highlights the intergenerational impact of trauma and highlights its epigenetic significance. The primary goal was to explore universal epigenetic mechanisms. Early understanding of ancestral history is crucial for personalized psychiatric care.