title: Functional biomarkers of depression: diagnosis, treatment, and pathophysiology.
abstract: Major depressive disorder (MDD) is a heterogeneous illness for which there are currently no effective methods to objectively assess severity, endophenotypes, or response to treatment. Increasing evidence suggests that circulating levels of peripheral/serum growth factors and cytokines are altered in patients with MDD, and that antidepressant treatments reverse or normalize these effects. Furthermore, there is a large body of literature demonstrating that MDD is associated with changes in endocrine and metabolic factors. Here we provide a brief overview of the evidence that peripheral growth factors, pro-inflammatory cytokines, endocrine factors, and metabolic markers contribute to the pathophysiology of MDD and antidepressant response. Recent preclinical studies demonstrating that peripheral growth factors and cytokines influence brain function and behavior are also discussed along with their implications for diagnosing and treating patients with MDD. Together, these studies highlight the need to develop a biomarker panel for depression that aims to profile diverse peripheral factors that together provide a biological signature of MDD subtypes as well as treatment response.
authors.affiliation: Department of Psychiatry, Center for Neurobiology and Behavior, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA. hschmidt@mail.med.upenn.edu
authors.forename: Heath D
authors.initials: HD
authors.lastname: Schmidt
authors.forename: Richard C
authors.initials: RC
authors.lastname: Shelton
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Duman
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D016207:Cytokines / Q000097:blood; D003866:Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D016896:Treatment Outcome
chemical_list: D000928:Antidepressive Agents; D015415:Biomarkers; D016207:Cytokines