Neuroinflammation in Late-Onset Schizophrenia: Viewing from the Standpoint of the Microglia Hypothesis

Schizophrenia develops mainly in adolescence, but late-onset schizophrenia (LOS) is not uncommon. According to the international consensus, schizophrenia which develops over 40 years old is called LOS and psychosis which develops over 60 years old is called very late-onset schizophrenia-like psychosis (VLOS). Compared to early-onset schizophrenia (EOS) that develops before the age of 40 years, LOS and VLOS are reported to be more common in women, and there are clinically clear differences such as less involvement of genetic factors than EOS. This review outlines the abnormalities of the neuroimmune system in the pathophysiology of LOS, especially focusing on the role of microglia.