Adjusted average changes in GDS score by changes in working status and post-retirement social participation.
GDS: the short version of the geriatric depression scale (ranging from 0 to 15, higher score indicates more depressive symptoms). Adjusted for changes in time varying confounding factors including equivalised houshold income, IADL limitation, marital status, stressful life events, social relationships. Subjects are those who did not show depression at baseline (GDS score < 5). Social participation with roles includes volunteering clubs and neighborhood councils. Recreational social participation includes sports organizations, hobby clubs, and older adults clubs