The use of new, creative approaches, e.g., analyzing bacteria-derived EVs from the serum microbiome in individuals with psychiatric disorders [71], or the development of a highly specific and sensitive ultra-performance liquid chromatography–tandem mass spectrometry method to detect activity of the enzyme catechol-O-methyltransferase (COMT) in EVs [72] might help to identify differentiating biomarkers. This evidence concerns the gene COMT and psychiatric disorder.