[Trauma, development, and attachment relationships].

Post-traumatic stress disorder (PTSD) is a heterogeneous form of psychopathology shaped by environmental and genetic factors, as well as their interaction. Although exposure to potentially traumatic events is common, only a minority of individuals develop PTSD, highlighting the role of attachment history, biological constitution, and specific details regarding the nature of the exposure and its consequences. This article integrates psychological, psychiatric, and developmental models of trauma, with a particular focus on complex PTSD, early-life stress, and intergenerational transmission within the parent-child relationship. Epidemiological, clinical, and neurobiological findings are discussed, along with their diagnostic and therapeutic implications. The article concludes that early, relational, and integrative interventions within a context of secure attachment are likely essential for preventing persistent psychopathology.