Postnatal Immune Activation: A Hidden Trigger for Mood Disorders?

Postnatal immune activation (PIA) is linked to persistent CNS homeostatic imbalance, which may contribute to the emergence of neuropsychiatric disorders such as depression and cognitive impairment. This process involves multiple pathological changes such as abnormal activation of central glial cells, neuroimmune disorders, and abnormal neural development during the embryonic period and the early postnatal period. Currently, the specific molecular mechanism by which PIA leads to the occurrence of emotional disorders is still not fully understood. This review summarizes evidence from animal models linking early postnatal immune challenges with later cognitive, anxiety-like, depression-like, and social outcomes, and systematically elaborates on the regulatory role of PIA in the occurrence and development of emotional disorders, aiming to deeply analyze its potential pathological mechanism and provide a basis for early prevention and targeted intervention in mental diseases such as depression and anxiety.