title: The clinical course and interrelations of dementia related symptoms.
abstract: ABSTRACTBackground:Dementia is a neurodegenerative syndrome that interferes with multiple aspects of life, including cognition, daily functioning, and behavior. Despite the large heterogeneity in symptom development, these three domains are seldom studied simultaneously. This study investigates how trajectories of these domains are interrelated within individuals over time, and how they in turn are related to dementia severity and quality of life (QoL).
  
  
  
  We used data from a longitudinal clinical cohort study, including 331 dementia patients. Cognitive status was measured using the Mini-Mental State Examination, daily functioning was measured with the disability assessment for dementia and neuropsychiatric symptoms (NPS) were scored using the neuropsychiatric inventory. We investigated the relationships in the time course of the various dementia domains using random effects multilevel models and parallel-process growth models.
  
  
  
  Changes in cognition and daily functioning were highly correlated over time (r = 0.85, p < 0.01), as were changes in NPS and functioning (r = -0.60, p < 0.01), while changes in cognition and NPS were not (r = -0.20, p = 0.06). All three domains were strongly associated with dementia severity over time (p < 0.01). Decreased functioning and increased NPS were both associated with decreased QoL (β = 2.97, p < 0.01 and β = -2.41, p < 0.01, respectively), while cognition was not (β = 0.01, p = 0.93).
  
  
  
  This study demonstrates the heterogeneity of dementia progression between individuals and between different dementia domains within individuals. To improve our understanding of dementia progression, future research should embrace a broader perspective encompassing multiple outcome measures along with the patient's profile, including neurological factors as well as physical, social, and psychiatric health.
authors.affiliation: Department of Geriatric Medicine,Radboud Institute for Health Sciences,Radboud University Medical Center,Reinier Postlaan 4,6525 GC,Nijmegen,the Netherlands.
authors.forename: Miriam L
authors.identifier: 0000-0002-3518-9152
authors.initials: ML
authors.lastname: Haaksma
authors.affiliation: Department of Psychiatry,Division of Geriatric Psychiatry and Neuropsychiatry,Johns Hopkins University School of Medicine,5300 Alpha Commons Drive,21224,Baltimore,Maryland,USA.
authors.forename: Jeannie-Marie S
authors.initials: JS
authors.lastname: Leoutsakos
authors.affiliation: VUmc Alzheimer Center,Neuroscience Campus Amsterdam,VU University Medical Center,De Boelelaan 1117,1081 HV,Amsterdam,the Netherlands.
authors.forename: Jonne A E
authors.initials: JAE
authors.lastname: Bremer
authors.affiliation: Department of Psychiatry and Neuropsychology,Maastricht University,School for Mental Health and Neuroscience,Alzheimer Center Limburg,Dr. Tanslaan 12,6229 ET,Maastricht,the Netherlands.
authors.forename: Pauline
authors.initials: P
authors.lastname: Aalten
authors.affiliation: Department of Psychiatry and Neuropsychology,Maastricht University,School for Mental Health and Neuroscience,Alzheimer Center Limburg,Dr. Tanslaan 12,6229 ET,Maastricht,the Netherlands.
authors.forename: Inez H G B
authors.initials: IHGB
authors.lastname: Ramakers
authors.affiliation: Department of Psychiatry and Neuropsychology,Maastricht University,School for Mental Health and Neuroscience,Alzheimer Center Limburg,Dr. Tanslaan 12,6229 ET,Maastricht,the Netherlands.
authors.forename: Frans R J
authors.initials: FRJ
authors.lastname: Verhey
authors.affiliation: Department of Geriatric Medicine,Radboud Institute for Health Sciences,Radboud University Medical Center,Reinier Postlaan 4,6525 GC,Nijmegen,the Netherlands.
authors.forename: Marcel G M
authors.initials: MGM
authors.lastname: Olde Rikkert
authors.affiliation: Department of Geriatric Medicine,Radboud Institute for Health Sciences,Radboud University Medical Center,Reinier Postlaan 4,6525 GC,Nijmegen,the Netherlands.
authors.forename: René J F
authors.initials: RJF
authors.lastname: Melis
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition / Q000502:physiology*; D003704:Dementia / Q000523:psychology*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D000073216:Mental Status and Dementia Tests; D008875:Middle Aged; D009426:Netherlands; D009483:Neuropsychological Tests; D011788:Quality of Life / Q000523:psychology*
keywords: activities of daily living; cognitive assessment; dementia; neuropsychiatric symptoms