title: Correlations among cognitive and behavioural assessments in patients with dementia due to Alzheimer's disease.
abstract: OBJECTIVE
  Primarily, we sought to verify correlations among assessments for cognition, behaviour and functional independence in a sample of patients with dementia due to Alzheimer's disease (AD). Secondarily, impacts of education, APOE haplotypes, length of dementia, age and alcohol use over the neuropsychiatric assessment were estimated.
  
  
  METHODS
  Patients with AD were assessed for demographic features, neuropsychiatric symptoms, cognitive test scores, functional impairment, caregiver burden and APOE haplotypes. Statistical comparisons were undertaken by way of Kruskal-Wallis test, linear regressions and Spearman correlations, significance at ρ < 0.05.
  
  
  RESULTS
  A total of 217 patients were included. Mean schooling was 4.21 ± 3.7 years, with significant impacts over cognitive tests. Mean age at examination was 78 ± 6.19 years-old, significantly influencing instrumental functionality. The mean length of the dementia syndrome was 5.4 ± 2.9 years, significantly impacting cognitive decline and functionality. Apathy was the most common behavioural symptom, negatively correlated with anxiety and delusions, and positively correlated with lifetime alcohol load. Patients with previous smoking or drinking habits were more likely to continue smoking or drinking later in life. APOE4+ haplotypes led to earlier dementia onset and significantly lower caregiver burden in mild dementia stages.
  
  
  CONCLUSIONS
  Most correlations among test results were highly significant, confirming that cognition, behaviour and functionality are usually interrelated in all stages of AD. Caregiver burden was correlated with behaviour, but not with cognition, and was lower for patients with APOE4+ haplotypes in mild dementia stages. Education is a major impact factor for cognitive performance.
authors.affiliation: Department of Neurology and Neurosurgery, Escola Paulista de Medicina, Federal University of São Paulo (UNIFESP), São Paulo, Brazil; Department of Morphology and Genetics, Escola Paulista de Medicina, Federal University of São Paulo (UNIFESP), São Paulo, Brazil. Electronic address: fabricioferreiradeoliveira@hotmail.com.
authors.forename: Fabricio Ferreira
authors.initials: FF
authors.lastname: de Oliveira
authors.affiliation: Department of Neurology and Neurosurgery, Escola Paulista de Medicina, Federal University of São Paulo (UNIFESP), São Paulo, Brazil.
authors.forename: Jose Roberto
authors.initials: JR
authors.lastname: Wajman
authors.affiliation: Department of Neurology and Neurosurgery, Escola Paulista de Medicina, Federal University of São Paulo (UNIFESP), São Paulo, Brazil.
authors.forename: Paulo Henrique Ferreira
authors.initials: PH
authors.lastname: Bertolucci
authors.affiliation: Department of Morphology and Genetics, Escola Paulista de Medicina, Federal University of São Paulo (UNIFESP), São Paulo, Brazil.
authors.forename: Elizabeth Suchi
authors.initials: ES
authors.lastname: Chen
authors.affiliation: Department of Morphology and Genetics, Escola Paulista de Medicina, Federal University of São Paulo (UNIFESP), São Paulo, Brazil.
authors.forename: Marilia Cardoso
authors.initials: MC
authors.lastname: Smith
mesh_terms: D000203:Activities of Daily Living; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000453:epidemiology; D000544:Alzheimer Disease / Q000453:epidemiology / Q000235:genetics / Q000523:psychology*; D001007:Anxiety / Q000453:epidemiology / Q000523:psychology; D057565:Apathy; D053327:Apolipoprotein E4 / Q000235:genetics; D017028:Caregivers; D003072:Cognition Disorders / Q000453:epidemiology / Q000523:psychology*; D015331:Cohort Studies; D004522:Educational Status; D005260:Female; D006212:Hallucinations / Q000453:epidemiology / Q000523:psychology*; D006239:Haplotypes; D006801:Humans; D016014:Linear Models; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D012720:Severity of Illness Index; D012907:Smoking / Q000453:epidemiology
chemical_list: D053327:Apolipoprotein E4
keywords: Activities of daily living; Alzheimer disease; Cognitive disorders; Dementia; Neuropsychiatry