title: Neurobiological correlates of depressive symptoms in people with subjective and mild cognitive impairment.
abstract: OBJECTIVE
  To test the hypothesis that depressive symptoms correlate with Alzheimer's disease (AD) type changes in CSF and structural and functional imaging including hippocampus volume, cortical thickness, white matter lesions, Diffusion tensor imaging (DTI), and fluoro-deoxy-glucose positron emission tomography (FDG-PET) in patient with subjective (SCI) and mild (MCI) cognitive impairment.
  
  
  METHODS
  In 60 patients, depressive symptoms were assessed using the Geriatric Depression Scale. The subjects underwent MRI, 18F-FDG PET imaging, and lumbar CSF extraction.
  
  
  RESULTS
  Subjects with depressive symptoms (n=24) did not have more pathological AD biomarkers than non-depressed. Uncorrected there were trends towards larger hippocampal volumes (P=0.06), less orbital WM damage measured by DTI (P=0.10), and higher orbital glucose metabolism (P=0.02) in the depressed group. The findings were similar when SCI and MCI were analyzed separately. Similarly, in patients with pathological CSF biomarkers (i.e., predementia AD, n=24), we found that correlations between scores on GDS and CSF Aß42 and P-tau indicated less severe AD-specific CSF changes with increasing depression.
  
  
  CONCLUSIONS
  Depressive symptoms are common in SCI/MCI, but are not associated with pathological imaging or CSF biomarkers of AD. Depression can explain cognitive impairment in SCI/MCI or add to cognitive impairment leading to an earlier clinical investigation in predementia AD.
authors.affiliation: Department of Geriatric Psychiatry, Akershus University Hospital, Ahus campus, Lørenskog, Norway; Institute of Clinical Medicine, Ahus campus University of Oslo, Oslo, Norway.
authors.forename: E
authors.initials: E
authors.lastname: Auning
authors.forename: P
authors.initials: P
authors.lastname: Selnes
authors.forename: R
authors.initials: R
authors.lastname: Grambaite
authors.forename: J
authors.initials: J
authors.lastname: Šaltytė Benth
authors.forename: A
authors.initials: A
authors.lastname: Haram
authors.forename: A
authors.initials: A
authors.lastname: Løvli Stav
authors.forename: A
authors.initials: A
authors.lastname: Bjørnerud
authors.forename: E
authors.initials: E
authors.lastname: Hessen
authors.forename: P K
authors.initials: PK
authors.lastname: Hol
authors.forename: A
authors.initials: A
authors.lastname: Muftuler løndalen
authors.forename: T
authors.initials: T
authors.lastname: Fladby
authors.forename: D
authors.initials: D
authors.lastname: Aarsland
mesh_terms: D000328:Adult; D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000000981:diagnostic imaging / Q000473:pathology / Q000523:psychology; D015415:Biomarkers / Q000134:cerebrospinal fluid; D002540:Cerebral Cortex / Q000473:pathology; D003072:Cognition Disorders / Q000134:cerebrospinal fluid / Q000000981:diagnostic imaging / Q000473:pathology / Q000523:psychology; D060825:Cognitive Dysfunction / Q000134:cerebrospinal fluid* / Q000000981:diagnostic imaging / Q000473:pathology / Q000523:psychology; D003863:Depression / Q000134:cerebrospinal fluid* / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000523:psychology; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D019788:Fluorodeoxyglucose F18; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals
chemical_list: D015415:Biomarkers; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Alzheimer's disease; depression; imaging; mild cognitive impairment; subjective cognitive impairment