Biomarkers

One of psychiatry’s significant challenges lies in differentiating certain mental illnesses, given the overlapping characteristics exhibited by many of them. The identification of a biomarker or a panel of biomarkers serving this purpose would represent a clinical revolution, motivating the scientific community to intensify their search. This chapter provides a concise historical overview of the quest for molecular biomarkers for schizophrenia spectrum disorders (SSD). Additionally, it outlines various classification patterns of biomarkers and attempts to categorize them based on hypotheses related to the pathophysiology of SSD. To help the reader comprehend the process of biomarker discovery, the chapter introduces the development of diagnostic models using machine learning. It delves into some of the multivariate analyses conducted and explains the evaluation of the model performance through the receiver operating characteristic (ROC) curve, providing detailed insights into result interpretation.