title: Integrated Biomarkers for Depression in Alzheimer's Disease: A Critical Review.
abstract: Depression is a common neuropsychiatric manifestation among Alzheimer's disease (AD) patients. It may compromise everyday activities and lead to a faster cognitive decline as well as worse quality of life. The identification of promising biomarkers may therefore help to timely initiate and improve the treatment of preclinical and clinical states of AD, and to improve the long-term functional outcome. In this narrative review, we report studies that investigated biomarkers for AD-related depression. Genetic findings state AD-related depression as a rather complex, multifactorial trait with relevant environmental and inherited contributors. However, one specific set of genes, the brain derived neurotrophic factor (BDNF), specifically the Val66Met polymorphism, may play a crucial role in AD-related depression. Regarding neuroimaging markers, the most promising findings reveal structural impairments in the cortico-subcortical networks that are related to affect regulation and reward / aversion control. Functional imaging studies reveal abnormalities in predominantly frontal and temporal regions. Furthermore, CSF based biomarkers are seen as potentially promising for the diagnostic process showing abnormalities in metabolic pathways that contribute to AD-related depression. However, there is a need for standardization of methodological issues and for replication of current evidence with larger cohorts and prospective studies.
authors.affiliation: Laboratory of Neuroimaging, Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe- University, Frankfurt/Main, Germany.
authors.forename: Sofia
authors.initials: S
authors.lastname: Wenzler
authors.affiliation: Laboratory of Neuroimaging, Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe- University, Frankfurt/Main, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Knochel
authors.affiliation: Laboratory of Neuroimaging, Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe- University, Frankfurt/Main, Germany.
authors.forename: Ceylan
authors.initials: C
authors.lastname: Balaban
authors.affiliation: Laboratory of Neuroimaging, Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe- University, Frankfurt/Main, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: Kraft
authors.affiliation: Laboratory of Neuroimaging, Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe- University, Frankfurt/Main, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Kopf
authors.affiliation: Translational Psychiatry Research Group and Department of Clinical Medicine, Faculty of Medicine, Federal University of Ceará, Fortaleza, CE, Brazil.
authors.forename: Gilberto S
authors.initials: GS
authors.lastname: Alves
authors.affiliation: Laboratory of Neuroimaging, Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe- University, Frankfurt/Main, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Prvulovic
authors.affiliation: Translational Psychiatry Research Group and Department of Clinical Medicine, Faculty of Medicine, Federal University of Ceará, Fortaleza, CE, Brazil.
authors.forename: Andre F
authors.initials: AF
authors.lastname: Carvalho
authors.affiliation: Laboratory for Neuroimaging, Dept. of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe- University, Heinrich-Hoffmann-Str. 10, 60528 Frankfurt, Germany.
authors.forename: Viola
authors.initials: V
authors.lastname: Oertel-Knochel
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis* / Q000235:genetics / Q000523:psychology*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000000981:diagnostic imaging; D003863:Depression / Q000150:complications / Q000000981:diagnostic imaging* / Q000235:genetics; D006801:Humans
chemical_list: D015415:Biomarkers
keywords: Alzheimer's disease; BDNF.; biomarkers; depression; depression in Alzheimer's Disease; genetics; neuroimaging; neurophysiology; serum biomarkers