Stressful life events in patients with Alzheimer’s disease (AD) may precede and/or follow the diagnosis. Although no clear causal inferences can be made about the effects of one or more perceived stressful life events on the likelihood of developing AD and/or on the prognosis of AD in older adults, this chapter aims to present the ways that healthcare experts measure stressful life events and their effects in older adults and explore the associations between different types of stressful life events, health outcomes, brain health, and other cognitive and emotional changes through the presentation of relevant research studies. This chapter goes on to discuss research not only in older humans but also animal models, as well as the neural mechanisms that may underlie these debated negative relationships. Possible interventions and methodological challenges for future research will be discussed.