["Australasian Journal on Ageing, Volume 45, Issue 2, June 2026. ", "\nABSTRACT\n\nObjectives\nThe aim of this study was to assess the longitudinal association between transitioning to adult caregiving, grandparent childcare and mental health outcomes (depressive symptoms, life satisfaction and cognitive functioning) and physical health outcomes (pain interference) in South Africa from 2015 to 2022.\n\n\nMethods\nWe used information from three waves of the ‘Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI)’. To evaluate within‐person changes over time, symmetric and asymmetric linear fixed‐effects (FE) regressions were employed and also stratified by sex.\n\n\nResults\nAdjusted FE regression analysis found a positive association between the change in grandchild care and beginning to provide grandchild care and depressive symptoms in the total sample and among women. Onset of adult caregiving, change in grandchild care and beginning to provide grandchild care were negatively associated with life satisfaction and positively associated with pain interference, while ceased grandchild care was positively associated with life satisfaction and negatively associated with pain interference. Onset of adult caregiving was negatively associated with cognitive functioning, and change in grandchild care and beginning to provide grandchild care were positively associated with cognitive functioning.\n\n\nConclusions\nTransitions into caregiving—both for grandchildren and adults—are associated with poorer well‐being, including higher depressive symptoms (especially among women), lower life satisfaction and greater pain interference, supporting a role‐strain perspective. However, initiating or changing grandchild care is linked to better cognitive functioning, suggesting potential stimulation benefits. In contrast, ceasing grandchild care is associated with improved life satisfaction and reduced pain.\n\n"]