title: Prevalence of neuropsychiatric symptoms in young-onset compared to late-onset Alzheimer's disease - part 1: findings of the two-year longitudinal NeedYD-study.
abstract: OBJECTIVE
  Knowledge about neuropsychiatric symptoms in young-onset Alzheimer's disease (YO-AD) is scarce, but essential to establish a prognosis and plan care for YO-AD patients. The aim of this study is to assess frequency parameters of neuropsychiatric symptoms in YO-AD over 2 years and investigate whether there are differences compared with late-onset Alzheimer's disease (LO-AD).
  
  
  METHODS
  98 YO-AD and 123 LO-AD patients and caregivers from two prospective cohort studies were included and assessed every 6 months for 2 years, using the Neuropsychiatric Inventory to evaluate neuropsychiatric symptoms.
  
  
  RESULTS
  Over the course of 2 years, the incidence, prevalence and persistence of neuropsychiatric symptoms were in general lower in YO-AD than in LO-AD, specifically for delusions, agitation, depression, anxiety, apathy, irritability and aberrant motor behavior. Frequency of individual symptoms showed large variability in both groups. Within the group of YO-AD patients, apathy was the most prevalent symptom.
  
  
  CONCLUSIONS
  Neuropsychiatric symptoms, notably apathy, should be paid appropriate attention to in the diagnosis and treatment of YO-AD patients. Further research is needed to gain insight into the mechanisms underlying the differences in neuropsychiatric symptoms between YO-AD and LO-AD.
authors.affiliation: School for Mental Health and Neuroscience, Alzheimer Center Limburg, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Deliane
authors.initials: D
authors.lastname: van Vliet
authors.forename: Marjolein E
authors.initials: ME
authors.lastname: de Vugt
authors.forename: Pauline
authors.initials: P
authors.lastname: Aalten
authors.forename: Christian
authors.initials: C
authors.lastname: Bakker
authors.forename: Yolande A L
authors.initials: YA
authors.lastname: Pijnenburg
authors.forename: Myrra J F J
authors.initials: MJ
authors.lastname: Vernooij-Dassen
authors.forename: Raymond T C M
authors.initials: RT
authors.lastname: Koopmans
authors.forename: Frans R J
authors.initials: FR
authors.lastname: Verhey
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology; D000544:Alzheimer Disease / Q000150:complications / Q000453:epidemiology* / Q000523:psychology*; D001007:Anxiety / Q000453:epidemiology / Q000209:etiology / Q000523:psychology; D015331:Cohort Studies; D003863:Depression / Q000453:epidemiology / Q000209:etiology / Q000523:psychology; D018450:Disease Progression; D004522:Educational Status; D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology* / Q000209:etiology / Q000523:psychology*; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D009483:Neuropsychological Tests; D009790:Occupations; D015995:Prevalence; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D012959:Socioeconomic Factors