Night Shifts Subtly Shrink Brain Regions, But Reversals Occur After Stopping

A large UK Biobank MRI study found that among 2,122 shift workers, there is a modest, symmetrical loss of brain volume in the right thalamus and left amygdala (areas tied to sleep regulation, emotion, and memory) with associated white‑matter changes. The negative association with cognitive performance is small, and the researchers caution interpretation. Importantly, ceasing shift work was linked to partial recovery of brain volume within about 2.5 years, suggesting a potential reversible window, though the study focused on older adults and applicability to younger workers remains uncertain.