This manuscript describes the basics of proteomic and metabolic profiling of blood serum and plasma from patients with psychiatric disorders. It will also explain the rationale behind the use of these body fluids due to need for user friendly and rapid tests in the clinic with simple sampling procedures. It has emerged over the last 15 years or so that psychiatric disorders are whole body diseases and the bloodstream is a means of molecular transport and therefore provides a conduit for two way communication with the brain. Here we also describe some of the basic biomarker findings from studies of serum or plasma from patients with psychiatric disorders like schizophrenia, major depression and bipolar disorder. Finally, we will discuss potential future advancements in this area which includes the development of held devices containing miniature proteomic and metabolic assays which can be used for facilitating diagnosis in a point-of-care setting and yield results in less than 15 minutes from a single drop of blood.