Linking early adversity epigenetics and neuropsychiatric disorders: Interaction between environment epigenetics and inherited susceptibility variants.

Early life adversity refers to adverse exposures (e.g., malnutrition, violence, psychologic stress) in early life and development that may induce long-lasting adaptations to these adverse environments. However, in situations where the environment no longer matches the one that induced these adaptations, this mismatch could lead to poor outcomes later in life. Early life adversity has been linked to neuropsychiatric outcomes in later life, such as mental health disorders, self-harming behaviors, suicidality, and substance dependence. This chapter examines the timing and types of the most common adversities, their cumulative effects, and the responsive mechanisms, including gene-environment interactions and epigenetic processes. Mechanisms involved in the link between early life adversity and later neuropsychiatric disorders are also explored, such as neuroendocrine networks and immune pathways. Characterizing resilience and susceptibility in the context of adversity can inform the identification of protective factors to combat this susceptibility, such as health and lifestyle changes during pregnancy and supportive family environments.