title: Informants' Perception of Subjective Cognitive Decline Helps to Discriminate Preclinical Alzheimer's Disease from Normal Aging.
abstract: BACKGROUND
  Self-reported and informant-reported subjective cognitive decline (SCD) may be useful in the detection of preclinical Alzheimer's disease (Pre-AD) and cognitive impairment related to abnormal amyloid-β (Aβ 42) levels.
  
  
  OBJECTIVE
  a) To compare the Subjective Cognitive Decline Questionnaire (SCD-Q) ratings between Pre-AD subjects and cognitively healthy controls, b) to study the association of SCD-Q scores with levels of AD biomarkers in cognitively healthy and cognitively impaired subjects, and c) to compare SCD-Q ratings in cognitively impaired subjects with or without abnormal Aβ 42.
  
  
  METHODS
  Two hundred and seventeen participants (111 subjects; 106 informants) answered the SCD-Q. All subjects underwent a lumbar puncture to determine levels of Aβ 42 and tau, and an extensive neuropsychological battery. Healthy subjects were classified as Controls (CTR) or Pre-AD according to the absence or the presence of abnormal Aβ 42, and those with cognitive impairment (CI) into Non-amyloid (NonAB-CI) or Amyloid (AB-CI) impairment.
  
  
  RESULTS
  Informants' SCD-Q scores were significantly higher in the Pre-AD group than in the CTR group (F = 6.75; p = 0.01). No significant differences were found in self-ratings. In the cognitively impaired groups, there were no significant differences in the SCD-Q ratings. In the whole sample, informants' ratings of SCD-Q correlated with Aβ 42 (r = -0.21; p = 0.02) and tau levels (r = 0.28; p = 0.00).
  
  
  CONCLUSIONS
  Higher informants' ratings of SCD-Q differentiated Pre-AD subjects from CTR. Informants' ratings of SCD-Q correlated weakly with cerebrospinal fluid AD biomarkers.
authors.affiliation: Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain.
authors.forename: Natalia
authors.initials: N
authors.lastname: Valech
authors.affiliation: Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain.
authors.forename: María A
authors.initials: MA
authors.lastname: Mollica
authors.affiliation: Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Olives
authors.affiliation: Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain.
authors.forename: Adriá
authors.initials: A
authors.lastname: Tort
authors.affiliation: Memory Unit, Neurology Service, Hospital Santa Creu i Sant Pau, Barcelona, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Fortea
authors.affiliation: Memory Unit, Neurology Service, Hospital Santa Creu i Sant Pau, Barcelona, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Lleo
authors.affiliation: Memory Unit, Neurology Service, Hospital Santa Creu i Sant Pau, Barcelona, Spain.
authors.forename: Sánchez-Saudinós
authors.initials: SS
authors.lastname: Belén
authors.affiliation: Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain.|Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Molinuevo
authors.affiliation: Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain.|Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Rami
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000544:Alzheimer Disease / Q000175:diagnosis*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid; D000704:Analysis of Variance; D058070:Asymptomatic Diseases / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D010446:Peptide Fragments / Q000134:cerebrospinal fluid; D010465:Perception / Q000502:physiology*; D012372:ROC Curve; D057566:Self Report; D011795:Surveys and Questionnaires; D016875:tau Proteins / Q000134:cerebrospinal fluid
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins
keywords: Amyloid-β; preclinical Alzheimer’s disease; subjective cognitive decline; tau proteins