Most studies on adversity highlight the negative impact of adversities on various outcomes, including brain and late-life cognition. However, some studies contradict this negative view of adversities on later life cognition and thus suggest that this association is more complex and depends on different factors.

The three studies in this thesis aimed to investigate the association between life course adversity and late-life cognition and to determine whether the association diverged according to some adversity characteristics and the cognitive outcomes investigated whilst considering some of the concerns and limitations raised in the literature.

Secondary analyses on three large databases, Vivre-Leben-Vivere, Survey of Health, Ageing, and Retirement in Europe, and UK Biobank were performed.

The results suggested that adversity may be important for shaping cognitive aging and supported the view that the association between adversity and later life cognition depends on the adversity experienced, its characteristics, and the cognitive outcome studied.