Social disengagement as a marker of cognitive decline (360G-Wellcome-200163_Z_15_Z)

Social disengagement is a criterion for dementia diagnosis but its timing is unknown. I aim to examine if social disengagement is an early behavioural marker for subsequent cognitive decline. Objectives 1) Test my hypothesis that social disengagement predicts subsequent cognitive decline. 2) Determine whether individuals whose social engagement decreases over 10 years are at higher risk of subsequent cognitive decline over 10 years than those with stable but low social engagement. 3) Explore the role of possible effect modifiers. Method Prospective cohort study, using participants from the Whitehall II cohort, and validating results with the Longitudinal Aging Study Amsterdam. These cohorts collected repeated measures of social and cognitive function. I will test my primary hypothesis using growth mixture modelling to categorise the cohorts’ trajectories of social change into homogeneous subpopulations, and then compare the rate of subsequent cognitive change in these different groups, using multilevel linear models. I will incorporate possible confounders. Key goals This research will elucidate the longitudinal association between social networks and cognitive function, clarifying the causal direction. This may provide new avenues for dementia research by detecting early markers or modifiable risk factors for cognitive decline, revealing new targets for aetiological and interventional research.