title: Depressive symptoms, chronic diseases, and physical disabilities as predictors of cognitive functioning trajectories in older Americans.
abstract: OBJECTIVE
  To determine the concurrent influence of depressive symptoms, medical conditions, and disabilities in activities of daily living (ADLs) on rates of decline in cognitive function of older Americans.
  
  
  METHODS
  Prospective cohort.
  
  
  METHODS
  National population based.
  
  
  METHODS
  A national sample of 6,476 adults born before 1924.
  
  
  METHODS
  Differences in cognitive function trajectories were determined according to prevalence and incidence of depressive symptoms, chronic diseases, and ADL disabilities. Cognitive performance was tested five times between 1993 and 2002 using a multifaceted inventory examined as a global measure (range 0-35, standard deviation (SD) 6.0) and word recall (range 0-20, SD 3.8) analyzed separately.
  
  
  RESULTS
  Baseline prevalence of depressive symptoms, stroke, and ADL limitations were independently and strongly associated with lower baseline cognition scores but did not predict future cognitive decline. Each incident depressive symptom was independently associated with a 0.06-point lower (95% confidence interval (CI)=0.02-0.10) recall score, incident stroke with a 0.59-point lower total score (95% CI=0.20-0.98), each new basic ADL limitation with a 0.07-point lower recall score (95% CI=0.01-0.14) and a 0.16-point lower total score (95% CI=0.07-0.25), and each incident instrumental ADL limitation with a 0.20-point lower recall score (95% CI=0.10-0.30) and a 0.52-point lower total score (95% CI=0.37-0.67).
  
  
  CONCLUSIONS
  Prevalent and incident depressive symptoms, stroke, and ADL disabilities contribute independently to poorer cognitive functioning in older Americans but do not appear to influence rates of future cognitive decline. Prevention, early identification, and aggressive treatment of these conditions may ameliorate the burdens of cognitive impairment.
authors.affiliation: Geriatric Research, Education, and Clinical Center, Health Services Research and Development Center of Excellence, Veterans Affairs Greater Los Angeles Health System, Los Angeles, California 90073, USA. jchodosh@mednet.ucla.edu
authors.forename: Joshua
authors.initials: J
authors.lastname: Chodosh
authors.forename: Dana
authors.initials: D
authors.lastname: Miller-Martinez
authors.forename: Carol S
authors.initials: CS
authors.lastname: Aneshensel
authors.forename: Richard G
authors.initials: RG
authors.lastname: Wight
authors.forename: Arun S
authors.initials: AS
authors.lastname: Karlamangla
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease / Q000453:epidemiology* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology / Q000523:psychology; D015331:Cohort Studies; D003863:Depression / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D006233:Persons with Disabilities / Q000523:psychology* / Q000706:statistics & numerical data; D042241:Early Diagnosis; D005260:Female; D016330:Frail Elderly; D006801:Humans; D015994:Incidence; D008297:Male; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012015:Reference Standards; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D020521:Stroke / Q000453:epidemiology / Q000523:psychology; D014481:United States / Q000453:epidemiology