Avenging Lamarck: the role of epigenetic in modulating reactions to traumatic events

Post Traumatic Growth and Post-Traumatic Stress disorder represent two parallel phenomena whose origin is a common ground, trauma. Following the Lamarck theory, recent epigenetic studies seem to confirm the importance of gene-environment interaction in determining different reactions to traumatic events that, according to the concept of Historical Trauma and Post-Traumatic Slave Syndrome, could interfere with the entire course of lives of a family and/or of a cultural group, becoming intergenerational. Recently, a growing field of research has focused on the associations between epigenome and mental illnesses, also including autism spectrum disorder (ASD), reporting a possible higher vulnerability to epigenetic alterations, in ASD subjects. Indeed, a greater neurobiological and genetic vulnerability to environment influences in association with the deficit in interaction and understanding of social stimuli make ASD subjects more easily exposed to trauma. On the other hand, these subjects, compared to neurotypical people, may more frequently develop positive reactions, thanks to divergent thinking that allows them to adopt a new point of view following stressful events. In this framework, the epigenome represents a new key to understand the impact on highly challenging events on illness trajectories and their role in mental disorders.