Loneliness is associated with poorer cognitive function in old age; however, the direction of this association is unknown. We tested for reciprocal associations between loneliness and the cognitive ability domains of processing speed, visuospatial ability, verbal memory, and crystalized ability.
We used three triennial waves of longitudinal data from the Lothian Birth Cohort Study 1936, and tested for cross-lagged associations between loneliness and cognitive abilities using cross-lagged panel models.
Better processing speed, visuospatial ability or crystallised ability at age 73, was associated with less positive changes in loneliness between ages 73 and 76; however, these associations were not replicated between ages 76 and 79. Loneliness at ages 73 and 76 did not predict subsequent changes in cognitive abilities.
Our findings indicate an association between cognitive ability and loneliness, such that individuals with lower cognitive abilities at age 73 may be at a slightly higher risk of becoming lonely. However, we did not find support for the hypothesis that loneliness causes a decline in cognitive health.