[Childhood and adolescent adversity : from toxic stress to clinical practice].

Adverse childhood experiences are common and have a lasting impact on physical and mental health, as well as on risky behaviors. The mechanisms involved include chronic activation of the stress response, as well as brain, immune, and epigenetic alterations that contribute to long-term vulnerability. However, these effects are not irreversible: the presence of protective factors can mitigate their consequences. Healthcare workers play a crucial role in strengthening parental and social support while promoting positive childhood experiences, all of which are key determinants of long-term health and development.