Neuroticism is linked to cognitive decline and increased risk of Alzheimer's disease through dysregulation of excitatory neurons

Abstract

INTRODUCTIONNeuroticism is an established risk factor for Alzheimers disease (AD), yet the molecular mechanisms linking this personality trait to neurodegeneration remain poorly understood. METHODSWe leveraged single-nucleus RNA-sequencing data from longitudinal cohort studies of cognitive aging (n = 655) to investigate the mechanisms mediating the association between neuroticism and AD. RESULTSWe identified two genes associated with neuroticism, both of which are downregulated in excitatory neurons: ADRA1B and LY6E-DT. In addition, we found that neuroticism is associated with enrichment of a specific excitatory neuron subpopulation: Exc.12. Further analysis revealed that Exc.12 partially mediates the relationship between neuroticism and AD, accounting for 12.2% of the total effect. DISCUSSIONThe dysregulation of excitatory neurons may represent a key cellular change that links neuroticism to AD.