A recent review of studies measuring proteins in blood serum/plasma illustrates the systemic nature of disease-related changes in patients with schizophrenia, major depressive and bipolar disorders. The collection of studies examined, including many that utilized Myriad RBM’s services, underscores the importance of including analysis of these peripheral proteins in the development of validated biomarker tests to advance treatment and diagnosis of psychiatric disorders. The review provides a concise evaluation of related research studies within the context of current clinical needs in the field of psychiatry.