OBJECTIVES: To investigate the effects of overwork on brain structure to better understand its impact on workers' cognitive and emotional health. The goal was to provide evidence for the potential neurological risks associated with prolonged working hours. METHODS: A total of 110 healthcare workers were classified into overworked (≥52 hours/week
n=32) and non-overworked groups (n=78). Brain volume differences were assessed using voxel-based morphometry (VBM) and atlas-based analysis. General linear models adjusted for age, sex and total intracranial volume were applied, and correlation analyses explored relationships between weekly working hours and brain volume in regions with significant differences. RESULTS: Overworked individuals exhibited significant changes in brain regions associated with executive function and emotional regulation. Atlas-based analysis revealed a 19% increase in left caudal middle frontal gyrus volume in the overworked group compared with the non-overworked group (p=0.006). VBM showed peak increases in 17 regions, including the middle frontal gyrus, insula and superior temporal gyrus (p<
0.05). Correlation analyses indicated a positive association between weekly working hours and brain volume changes in the middle frontal gyrus and insula. CONCLUSIONS: This study provides preliminary evidence that overwork is associated with structural brain changes, particularly in regions linked to cognition and emotion. These findings provide novel neurobiological evidence linking prolonged working hours to structural brain changes, emphasising the need for further research to understand the long-term cognitive and emotional implications of overwork.