Abstract: Characterized by positive symptoms (such as changes in behavior or thoughts, including delusions and hallucinations), negative symptoms (such as apathy, anhedonia, and social withdrawal), and cognitive impairments, schizophrenia is a chronic, severe, and disabling mental disorder with late adolescence or early adulthood onset. Antipsychotics are the most commonly used drugs to treat schizophrenia, but those currently in use do not fully reverse all three types of symptoms characterizing this condition. Schizophrenia is frequently misdiagnosed, resulting in a delay of or inappropriate treatment. Abnormal expression of microRNAs is connected to brain development and disease and could provide novel biomarkers for the diagnosis and prognosis of schizophrenia. The recent studies reviewed included microRNA profiling in blood- and urine-based materials and nervous tissue materials. From the studies that had validated the preliminary findings, potential candidate biomarkers for schizophrenia in adults could be miR-22-3p, -30e-5p, -92a-3p, -148b-5p, -181a-3p, -181a-5p, -181b-5p, -199b-5p, -137 in whole blood, and miR-130b, -193a-3p in blood plasma. Antipsychotic treatment of schizophrenia patients was found to modulate the expression of certain microRNAs including miR-130b, -193a-3p, -132, -195, -30e, -432 in blood plasma. Further studies are warranted with adolescents and young adults having schizophrenia and consideration should be given to using animal models of the disorder to investigate the effect of suppressing or overexpressing specific microRNAs.

Key words: antipsychotics, biomarkers, blood exosomes, blood plasma, brain tissue exosomes, brain tissues, leukocytes, microRNAs, neural stem cells, olfactory neuroepithelium, schizophrenia, whole blood