LAUSR

Abstract Framed by a life course perspective and the stress process, this study examines how life stage at chronic illness onset contributes to mental health disparities among adults with particular attention to the moderating role of personal mastery. Using secondary data from waves 1–4 of the American Changing Lives survey, this study uses multilevel modeling analyses to examine if the life stage (early adulthood, midlife, and late life) in which an adult becomes ill is associated with his/her depressive symptoms across a 16-year period and how the relationship is moderated by mastery. The results confirm that becoming chronically ill early in the adult life course (before 36) is particularly detrimental to the mental health of adults when compared to illness onset at late life (65+), which is due in part to younger adults yielding less psychological protection from the mastery they possess than adults who become ill as older adults. Thus, this study’s findings support that life stage, like race, socioeconomic status and other individual contexts, differentially position people to experience the negative psychological effects of the stressor of chronic illness.