The association between cardiovascular disease and cognitive decline varies by long-term depressive symptom trajectories in older adults

Cardiovascular disease (CVD) and depressive symptoms are established risk factors for cognitive decline in later life, but it remains unclear whether long-term depressive symptom burden modifies the association between CVD and cognitive ageing. We used data from 5423 adults aged 50 years and older in the English Longitudinal Study of Ageing between 2004 and 2018. Depressive symptoms were assessed repeatedly using the eight-item Center for Epidemiologic Studies Depression Scale, and growth mixture modelling was used to identify long-term symptom trajectories. Linear mixed-effects models examined associations between baseline CVD, depressive symptom trajectories, and changes in global cognition, memory, semantic fluency, and orientation. Three trajectories were identified: low-stable, moderate-stable, and high-stable. Participants with moderate-stable and high-stable depressive symptoms had poorer baseline cognitive performance and faster decline in global cognition, memory, and semantic fluency than those with low-stable symptoms. Baseline CVD was associated with faster cognitive decline, but the CVD-related difference was most evident in the low-stable group and attenuated among participants with higher depressive symptom burden. These findings suggest that persistent depressive symptoms may shape the observable association between CVD and cognitive ageing, highlighting the importance of considering long-term mental health burden in cognitive risk assessment.