Where Do We Stand in the Quest for Neuropsychiatric Biomarkers and Endophenotypes and What Next?

Abstract

Although biomarker science is a field that is advancing rapidly in medicine as a whole, neuropsychiatric disorders are still characterized by an absence of the biomarkers and laboratory tests that will promote new diagnostic and prognostic procedures. Recent advances in genomic, genetic, epigenetic, neuroscience, proteomic and metabolomic knowledge and technologies have opened the way to searching for biomarkers, however, it is still a relatively new field for neuropsychiatry. In addition, candidate endophenotypes, important trait markers widely used for genetic studies, are useful for the development of heritable diagnostic and prognostic biomarkers (endophenotype strategy). This chapter provides definitions of biomarkers and endophenotypes, elucidating their types and properties that will make them useful in neuropsychiatric research and practice. Recent results in the schizophrenia and mood disorders literature that illustrate the usefulness of biomarkers and endophenotypes are also reviewed. We predict that both biomarker and endophenotypic approaches will open new avenues for practically important applications of genetics, neuroscience and "omics" advantages in neuropsychiatry.