The effects of functional decline upon social networks, life satisfaction,
and depression were observed and statistically tested in a longitudinal pro
spective design. Subjects were 692 Japanese elderly, aged sixty-five years
or older, with high functional capacity at baseline. During a two-year peri
od of follow-up, 12.3 percent of the subjects experienced functional declin
e. Repeated-measure analyses of covariance with statistical tests for simpl
e main effects revealed that changes in the criterion variables significant
ly differed along with changes in functional health status when the effects
of age, gender, and socioeconomic status were controlled. The subjects who
experienced functional decline showed a larger decrease in the number of r
elatives, friends, and neighbors having frequent contacts, a larger decline
in life satisfaction, and a larger increase in depression than those witho
ut functional decline. The results seem to confirm further the importance o
f functional health status as a prerequisite for higher quality of life in
old age.