Abstract While many describe changes in mental health over the pandemic, we investigate change in resilience over time during the pandemic. Stress resilience can be operationalised as stressor reactivity, that is, how much a person’s mental health is affected by the stressors that they experience. Utilising the individual participant data (IPD) meta-analyses megadataset available we first define and quantify how many stressors individuals. We then regress this stressor exposure on mental health within each sample to compute each sample’s normative stressor reactivity. Each person’s individual stressor reactivity is then calculated as the residual to this line at each time points. Resilient outcomes can be understood as lower reactivity as this indicates lower susceptibility to stressors. Stressor reactivity (SR) scores control for individual stressor exposure, therefore allowing us to investigate resilience factors during a time in which exposure to macro and micro stressors varied greatly between individuals. Further, SR scores are a harmonised outcome that can easily compared across different samples in the IPD dataset. Using this outcome, we present findings on resilience trajectories and identify factors that are associated with resilient outcomes. We also disentangle the role of current stressor exposure and prior stressors, showing that prior exposure to stressors increases vulnerability in subsequent exposures. Our findings show that stressor reactivity over time was more stable than mental health symptoms during the pandemic, therefore indicating that SR as an outcome offers new insights into the impact of the pandemic.