title: Aging and the shape of cognitive change before death: terminal decline or terminal drop?
abstract: OBJECTIVE
  Relative to typical age-related cognitive decrements, the terms "terminal decline" and "terminal drop" refer to the phenomenon of increased cognitive decline in proximity to death. Given that these terms are not necessarily synonymous, we examined the important theoretical distinction between the two alternative trajectories or shapes of changes they imply.
  
  
  METHODS
  We used 12-year (5-wave) data from the Victoria Longitudinal Study to directly test whether pre-death cognitive decrements follow a terminal decline (generally gradual) or a terminal drop (more abrupt) shape. Pre-death trajectories of cognitive decline for n=265 decedents (Mage = 72.67 years, SD = 6.44) were examined separately for 5 key cognitive constructs (verbal speed, working memory, episodic memory, semantic memory, and crystallized ability).
  
  
  RESULTS
  Several classes of linear mixed models evaluated whether cognitive decline increased per additional year closer to death. Findings indicated that the shape of pre-death cognitive change was predominantly characterized by decline that is steeper as compared with typical aging-related change, but still best described as slow and steady decline, especially as compared with precipitous drop.
  
  
  CONCLUSIONS
  The present findings suggest that terminal decline and terminal drop trajectories may not be mutually exclusive but could rather reflect distinct developmental trajectories within the same individual.
authors.affiliation: Department of Psychology, University of Victoria, Victoria, BC V8W 3P5, Canada. smacd@uvic.ca
authors.forename: Stuart W S
authors.initials: SW
authors.lastname: MacDonald
authors.forename: David F
authors.initials: DF
authors.lastname: Hultsch
authors.forename: Roger A
authors.initials: RA
authors.lastname: Dixon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology; D003643:Death; D003704:Dementia / Q000523:psychology; D006801:Humans; D008137:Longitudinal Studies; D008568:Memory; D008875:Middle Aged