Adjusted average changes in GDS score by changes in working status and occupational class.
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). Occupational status: 1 = high (professionals and engineering, managers), 0 = low (clerical support workers, service and sales workers, craft and related trades workers, skilled agricultural, forestry, and fishery workers, others)