Chronic Toxoplasma gondii (T. gondii) infection is a widespread condition that can negatively affect brain function and is considered a risk factor for various psychiatric conditions, including depression and schizophrenia. This prospective observational study aims to investigate the expression levels of specific circulating microRNAs (miRNAs) in women diagnosed with schizophrenia, major depressive disorder, or bipolar disorder who also have chronic toxoplasmosis. By comparing these levels to patients without the infection, the study seeks to determine if these miRNAs can serve as biological markers to help differentiate between specific psychological disorders and identify the impact of chronic toxoplasmosis on mental health.