Gender differences in the trajectories and the risk factors of depressive symptoms in later life.

BACKGROUND: The present study investigated changes in the trajectories of depressive symptoms in the elderly and attempted to identify risk factors that influence these changes according to gender. METHODS: All data were obtained from a subsample of subjects who participated in the Korean Longitudinal Study of Ageing between 2006 and 2012; 3,667 individuals (1,566 men and 2,101 women) aged 60 years and older were included in the present study. A group-based trajectory model was employed to determine the appropriate number of groups and to observe changes in depressive symptoms according to research year. Following the trajectory analysis, a multinomial regression analysis was performed to examine depressive symptom-related risk factors that influenced membership in the different trajectory groups. RESULTS: Significant gender differences were found in the trajectories of depressive symptoms among four groups (normal, mild depressed, worsening, and depressed) in men and five groups (normal, mild depressed, worsening, improving, and depressed) in women. Among the trajectory groups, physical health status such as chronic diseases, self-rated health (SRH), and somatic pain showed statistically significant differences in both genders. In addition, employment in men and social participation in women were associated with the trajectories. CONCLUSIONS: The present study suggested that maintaining one's physical health status played an important role in preventing depressive symptoms and that employment in men and social participation in women were preventative against the development of depressive symptoms.