In a 22-year Australian population-based panel, all seven adverse life events were associated with negative mental health impacts at each occurrence, but responses to repeated exposure were event-specific (sensitisation for some, habituation for others, no clear pattern for the rest), giving no consistent support for a single universal model of stress-response.
Every one of the seven adverse life events examined was associated with a significant negative mental health impact at each occurrence.
Sensitisation (worsening response with repeated exposure) was observed for major worsening in finances and for victimisation by property crime.
Habituation (diminishing response with repeated exposure) was observed for separation/divorce and for serious personal injury/illness.
No clear association with repeated exposure was found for physical violence, serious family injury/illness, and firing/redundancy.
Sensitisation and habituation effects appeared to plateau after the second adverse event rather than accumulating with further exposure.
The findings were robust to adjustment for pre-event mental health and to a Mundlak correction.
The results do not support a single universal model of stress response; responses to adversity appear event-specific and may depend on contextual factors.
This study followed a large, representative group of Australians over 22 years to see how repeated bad life events affect mental health. It looked at seven common types of adversity, such as separation or divorce, serious illness or injury, financial setbacks, property crime, physical violence, serious illness in the family, and job loss. Every type of event was linked to worse mental health when it happened, including when it happened again. What differed was how people responded to repeat events. For major financial worsening and property crime, the mental health impact tended to get worse with repetition (sensitisation). For separation/divorce and serious personal injury or illness, the impact tended to lessen (habituation). For physical violence, serious family illness or injury, and job loss, no clear pattern emerged. Where changes did occur, they mostly appeared by the second event and did not keep growing with further events. The results held up when the researchers accounted for people's mental health before the event. This research suggests that there is no single rule for how people respond to repeated hardship; the saying that what doesn't kill you makes you stronger does not hold across the board. The type of adversity seems to matter, and factors such as the meaning people give to events, their resilience, and available resources may play a role. This is an observational study, so it describes patterns rather than proving causes.
Chye A, Morris R, Glozier N. (2026). 'What doesn't kill you doesn't always make you stronger': The impact of repeated exposure to adverse life events on mental health.. Psychological medicine. https://doi.org/10.1017/S0033291726105479