Latent class growth modeling of depression and anxiety in older adults: an 8-year follow-up of a population-based study.

Background Depression and anxiety are common mental health conditions in the older adult population. Understanding the trajectories of these will help implement treatments and interventions. Aims This study aims to identify depression and anxiety trajectories in older adults, evaluate the interrelationship of these conditions, and recognize trajectory-predicting characteristics. Methods Group-based dual trajectory modeling (GBDTM) was applied to the data of 3983 individuals, aged 65 years or older who participated in the Korean Health Panel Study between 2008 and 2015. Logistic regression was used to identify the association between characteristics and trajectory groups. Results Four trajectory groups from GBDTM were identified within both depression and anxiety outcomes. Depression outcome fell into "low-flat (87.0%)", "low-to-middle (8.8%)", "low-to-high (1.3%)" and "high-stable (2.8%)" trajectory groups. Anxiety outcome fell into "low-flat (92.5%)", "low-to-middle (4.7%)", "high-to-low (2.2%)" and "high-curve (0.6%)" trajectory groups. Interrelationships between depression and anxiety were identified. Members of the high-stable depression group were more likely to have "high-to-low" or "high-curved" anxiety trajectories. Female sex, the presence of more than three chronic diseases, and being engaged in income-generating activity were significant predictors for depression and anxiety. Conclusions Dual trajectory analysis of depression and anxiety in older adults shows that when one condition is present, the probability of the other is increased. Sex, having more than three chronic diseases, and not being involved in income-generating activity might increase risks for both depression and anxiety. Health policy decision-makers may use our findings to develop strategies for preventing both depression and anxiety in older adults.