Sex Differences in Neural Activity during Worry Induction and Reappraisal in Late Life.

BACKGROUND: Severe worry - a symptom of mood and anxiety disorders - is more prevalent in women than men across the lifespan. The neural processes contributing to this difference remain unclear, especially in older adults where severe worry is related to higher cerebrovascular and neurodegenerative processes. In this study, we analyzed regional brain activation during an in-scanner worry induction task to elucidate the neural basis of worry-related sex differences among older adults. METHODS: 131 older adults completed a fMRI worry induction and reappraisal task. Voxel-wise t-tests were used to compare sex differences across contrasts. Activity from regions with voxel-wise differences were analyzed using regression to determine the effect of worry severity and cognitive regulation strategies. RESULTS: Greater reappraisal use was associated with less severe worry. Compared with women, men used suppression more frequently and reported lower in-scanner worry levels following worry induction. Women had greater activity than men on the worry-neutral contrast in the bilateral cerebellum declive, left middle occipital gyrus, right cuneus, and left precuneus; and on the worry-fixation contrast in the putamen, hippocampus, ventral posterolateral nucleus of the thalamus, superior temporal, amygdala, ventral lateral nucleus of the thalamus, and pallidum. Activation in the left amygdala, left precuneus, and left middle occipital were differentially associated by sex with use of reappraisal. CONCLUSIONS: Differences in brain activity reveal older women recruit regions related to complex visual tasks and emotion regulation. These regions were previously associated with worry induction and maintenance networks, supporting the higher prevalence of chronic, difficult-to-control worry among older women.