Affective development in advanced old age: analyses of terminal change in positive and negative affect.

Late-life development of affect may unfold terminal changes that are driven more by end-of-life processes and not so much by time since birth. This study aimed to explore time-to-death-related effects in measures of affect in a sample of the very old. We used longitudinal data (2 measurement occasions: 2002 and 2003) from 140 deceased participants, covering a period of up to 9 years to death, from a German oldest-old sample between 80 and 90 years old at baseline measurement (Projects ENABLE-AGE and LateLine). Nonlinear time-to-death and age effects on baseline level and intraindividual 1-year changes in positive affect (PA) and negative affect (NA) were analyzed with latent change score models. With respect to PA, no time-to-death-related effects were discovered, but linear age-related decline was found. For NA, time-to-death effects were found for both baseline level and 1-year change, indicating an increase of NA closer to death, which turns around to a rapid reduction of NA in the approach of the end of life. These effects suggest a twofold dynamic of terminal changes in NA. First, a general increase of NA across a larger period preceding death potentially mirrors basic processes of degradation of the human system. Second, approaching the end, these processes may exhaust negative activation, prompting a terminal drop of NA close to death.