Background <p>Informal caregivers of individuals with dementia experience substantial psychological and physical burdens, with bereavement marking a critical transition. However, the longitudinal trajectories of their emotional responses remain poorly understood within conventional psychiatric frameworks. This study aimed to systematically synthesize longitudinal evidence on the emotional changes experienced by informal dementia caregivers before and after bereavement.</p> Methods <p>A comprehensive search of MEDLINE and EMBASE was conducted to identify prospective observational studies assessing emotional changes in informal dementia caregivers. Eligible studies included at least two assessment points (one pre-bereavement) and a minimum follow-up of six months. The quality of the included studies was evaluated using the modified Newcastle-Ottawa Scale.</p> Results <p>The analysis of seven longitudinal studies confirmed that caregivers’ experiences follow complex, multidimensional trajectories. Emotional outcomes were mixed: complicated grief tended to alleviate, depression/anxiety were heterogeneous, and loneliness tended to worsen. Notably, a trend of increased long-term depression was observed in women. The divergent trajectories between psychological recovery and physical burden were evident: role burden and mental quality of life recovered, while physical quality of life and immune function declined. Protective factors included the cessation of caregiving burden and a pre-bereavement social network.</p> Conclusion <p>These findings underscore that emotional adaptation is a multidimensional phenomenon requiring support strategies tailored to timing, gender, and individual resources. Strengthening protective factors in the pre-bereavement stage and addressing persistent physical burden in the long term are critical for effective preventive management.</p>