Hippocampal and limbic microstructure changes associated with stress across the lifespan: a UK biobank study.

Experiencing highly stressful events can have detrimental and lasting effects on brain morphology. The current study explores the effects of stress during childhood and adulthood on grey matter macro- and microstructure using a sub-sample of 720 participants from the UK Biobank with very high or very low childhood and adulthood stress scores. We used T1-weighted and diffusion MRI data to assess grey matter macro- and microstructure within bilateral hippocampus, amygdala and thalamus. Findings showed that childhood stress is associated with changes in microstructural measures bilaterally within the hippocampus and amygdala. No effects of adulthood stress on brain microstructure were found. No interaction effects between sex and stress (either childhood or adulthood) were observed for any brain imaging measure. Analysis of sub-segments of the hippocampus showed that childhood stress predominantly impacted the bilateral heads of the hippocampus. Overall, these findings suggest that highly stressful experiences during childhood, but not adulthood, have lasting impact on brain microstructure. The effects of these experiences in childhood appear to persist regardless of experiences of high or low stress in adulthood.