22 May 24. Featured Paper

Life-course neighbourhood deprivation and brain structure in older adults: the Lothian Birth Cohort 1936

Link to paper on Nature

Authors

Gergő Baranyi, Colin R. Buchanan, Eleanor L. S. Conole, Ellen V. Backhouse, Susana Muñoz Maniega, María del C. Valdés Hernández, Mark E. Bastin, Joanna Wardlaw, Ian J. Deary, Simon R. Cox & Jamie Pearce

Abstract

Neighbourhood disadvantage may be associated with brain health but the importance of exposure at different stages of the life course is poorly understood. Utilising the Lothian Birth Cohort 1936, we explored the relationship between residential neighbourhood deprivation from birth to late adulthood, and global and local neuroimaging measures at age 73. A total of 689 participants had at least one valid brain measures (53% male); to maximise the sample size structural equation models with full information maximum likelihood were conducted. Residing in disadvantaged neighbourhoods in mid- to late adulthood was associated with smaller total brain (β = −0.06; SE = 0.02; sample size[N] = 658; number of pairwise complete observations[n]=390), grey matter (β = −0.11; SE = 0.03; N = 658; n = 390), and normal-appearing white matter volumes (β = −0.07; SE = 0.03; N = 658; n = 390), thinner cortex (β = −0.14; SE = 0.06; N = 636; n = 379), and lower general white matter fractional anisotropy (β = −0.19; SE = 0.06; N = 665; n = 388). We also found some evidence on the accumulating impact of neighbourhood deprivation from birth to late adulthood on age 73 total brain (β = −0.06; SE = 0.02; N = 658; n = 276) and grey matter volumes (β = −0.10; SE = 0.04; N = 658; n = 276). Local analysis identified affected focal cortical areas and specific white matter tracts. Among individuals belonging to lower social classes, the brain-neighbourhood associations were particularly strong, with the impact of neighbourhood deprivation on total brain and grey matter volumes, and general white matter fractional anisotropy accumulating across the life course. Our findings suggest that living in deprived neighbourhoods across the life course, but especially in mid- to late adulthood, is associated with adverse brain morphologies, with lower social class amplifying the vulnerability.

Conclusions

Living in deprived neighbourhoods was associated with markers of poorer brain health among older adults. Neighbourhood deprivation during mid- to late adulthood (age 40–69 years) was associated with brain structural differences in older age, but we also found some evidence for the accumulating impact of neighbourhood deprivation across the entire life course, especially among socially disadvantaged individuals. The life-course approach can provide useful insights into how the social environment might ‘get under the skin,’ and future research should apply it more often to understand differences and changes in brain morphology and related cognition. Greater understanding of relevant brain regions, social and physical neighbourhood features pertinent to brain health, and potential causal pathways require further research attention.

Keywords:

• Lothian Birth Cohort 1936