A large body of literature shows that the emotional health of rural elders in China is negatively affected by the migration of their adult children. However, the precise mechanism that underpins this relationship has yet to be fully uncovered. This paper introduces two new dimensions of analysis to expand the understanding of this ‘left behind’ phenomenon, and offers statistical insights, theoretical explanations and policy recommendations, as well as suggestions for further study. Firstly, in this paper, rural elders have been distinguished based on whether all, or any, of their adult children have migrated. This distinction leads to the finding that rural elders suffer more adverse mental health impacts when all adult children from a household move away. Secondly, the temporal dimension of migration is investigated, finding that there is a ‘turning point’ after which the mental health of rural elders appears to recover after the migration of their adult children. Comparison of the two groups shows that rural elders who see any of their adult children migrate recover from depression twice as quickly as those who see all of their children migrate. Receiving financial support or providing child care can only partly mediate the negative influence of migration. Also, the level of depression and wellbeing of rural elders can be significantly moderated by the emotional closeness between them and their adult children. Providing (grand)child-care assistance and receiving economic support is shown to have smaller mitigating effects. This paper concludes with a discussion of how the notion of ‘filial piety’ could, directly and indirectly, play a role in the emotional health of rural elders, with policy implications provided.