Figure 1. Study Design Showing the Time Line of Analysis.
The time line was used to investigate the association between depressive symptom trajectories over years 1 through 5 and subsequent risk of dementia after year 5. Comorbidities and other health factor variables were assessed at year 5 to adjust models for health factors that had developed by the end of the depressive symptom assessment period. To adjust for differences in overall level of cognitive functioning and cognitive change during the depressive symptom assessment period, models were adjusted for the mean Modified Mini-Mental State Examination score over years 1 through 5 and the Modified Mini-Mental State Examination difference score (year 5 minus year 1).