The effects of stress across the lifespan on the brain, cognition and mental health: A UK biobank study

Repeated overstimulation of the stress response system, caused by exposure to prolonged highly stressful experiences, is thought to affect brain structure, cognitive ability, and mental health. We tested the effects of highly stressful experiences during childhood and adulthood using data from the UK Biobank, a large-scale national health and biomedical study with over 500,000 participants. To do this, we defined four groups with high and low levels of childhood and adulthood stress. We then used T1- and diffusion-weighted MRI data to assess the macrostructure in grey matter and microstructure in white matter of limbic brain regions, commonly associated with the stress response. We also compared executive function and working memory between these groups. Our findings suggest that in females, higher levels of both childhood and adulthood stress were associated with reduced connectivity within the posterior thalamic radiation. High stress in both childhood and adulthood was associated with decreases in both executive function and working memory. Finally, stress across the lifespan was positively associated with the number of diagnosed mental health problems, with a stronger effect in females than in males. Together our findings demonstrate links between stress across the lifespan, brain structure and mental health outcomes that may differ between males and females. Our findings also suggest that exposure to highly stressful life events has a negative impact on cognitive abilities in later life regardless of sex.