Anxiety, brain structure and socioeconomic status in middle-aged and older adults

Anxiety disorders confer a significant global burden, impacting mental health, quality of life, and well-being, particularly in aging populations. Prior studies showed the association between anxiety and abnormal brain structure, and socioeconomic status (SES) is linked with both anxiety and brain structure. However, limited research considers the interaction between these three factors, particularly in older adults. Multivariate regression analysis was conducted using 27,563 participants from the UK Biobank to investigate the relationship between anxiety and brain volume in 30 cortical and subcortical regions for the whole sample and separately by sex. It then investigated whether SES affects this relationship. Five out of 30 brain regions had significant negative associations with anxiety in the whole population. These were the thalamus, gyrus, insular cortex, supramarginal gyrus and precentral gyrus, but these relationships were abolished in each area apart from the precentral gyrus when SES was included in analyses. For females, no significant associations were found. For males, lower volume in the precentral gyrus was significantly associated with higher anxiety, but this relationship was no longer significant when SES was considered. The precentral gyrus was most robustly associated with anxiety across analyses. However, participants with conditions that may affect the brain were not excluded and time between anxiety assessment and brain scans varied widely across participants. Information about past SES during brain development is also not available. To conclude, the relationship between anxiety and brain volume is affected by SES. Clinicians and researchers should take this into account when working with imaging data.