title: Depressive Symptoms and Biomarkers of Alzheimer's Disease in Cognitively Normal Older Adults.
abstract: Even low levels of depressive symptoms are associated with an increased risk of cognitive decline in older adults without overt cognitive impairment (CN). Our objective was to examine whether very low, "subthreshold symptoms of depression" are associated with Alzheimer's disease (AD) biomarkers of neurodegeneration in CN adults and whether these associations are specific to particular depressive symptoms. We analyzed data from 248 community-dwelling CN older adults, including measurements of cortical amyloid burden, neurodegeneration markers of hippocampal volume (HV) and cerebral 18F-fluorodeoxyglucose (FDG) metabolism in a composite of AD-related regions and the 30-item Geriatric Depression Scale (GDS). Participants with GDS >10 were excluded. General linear regression models evaluated the cross-sectional relations of GDS to HV or FDG in separate backward elimination models. Predictors included GDS total score, age, gender, premorbid intelligence, a binary amyloid variable and its interaction with GDS. Principal component analyses of GDS item scores revealed three factors (the Dysphoria, Apathy-Anhedonia, and Anxiety-Concentration Factors). In secondary analyses, GDS total score was replaced with the three factor scores in repeated models. Higher GDS score (p = 0.03) was significantly associated with lower HV and was marginally related (p = 0.06) to FDG hypometabolism. In secondary models, higher Dysphoria (p = 0.02) and Apathy-Anhedonia (p = 0.05) were related to lower HV while higher Apathy-Anhedonia (p = 0.003) was the sole factor related to FDG hypometabolism. Amyloid was not a significant predictor in any model. In conclusion, very low-level dysphoria, apathy and anhedonia may point to neurodegeneration in AD-related regions but this association appears to be independent of amyloid burden.
authors.affiliation: Center for Alzheimer Research and Treatment, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Donovan
authors.affiliation: Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Hsu
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.|Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Dagley
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.|Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Schultz
authors.affiliation: Center for Alzheimer Research and Treatment, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Amariglio
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Mormino
authors.affiliation: Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Olivia I
authors.initials: OI
authors.lastname: Okereke
authors.affiliation: Center for Alzheimer Research and Treatment, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Dorene M
authors.initials: DM
authors.lastname: Rentz
authors.affiliation: Center for Alzheimer Research and Treatment, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Johnson
authors.affiliation: Center for Alzheimer Research and Treatment, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Reisa A
authors.initials: RA
authors.lastname: Sperling
authors.affiliation: Center for Alzheimer Research and Treatment, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Gad A
authors.initials: GA
authors.lastname: Marshall
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000544:Alzheimer Disease / Q000150:complications* / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000814:Aniline Compounds / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D003863:Depression / Q000209:etiology*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D015577:Geriatric Assessment; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D049268:Positron-Emission Tomography; D025341:Principal Component Analysis; D011569:Psychiatric Status Rating Scales; D012111:Residence Characteristics; D013844:Thiazoles / Q000378:metabolism
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D016229:Amyloid beta-Peptides; D000814:Aniline Compounds; D015415:Biomarkers; D013844:Thiazoles; D019788:Fluorodeoxyglucose F18
keywords: Alzheimer’s disease; biomarkers; neurodegeneration; normal cognition; preclinical; subthreshold depressivesymptoms