Sex-specific differences in amygdala resting-state functional connectivity with trait anxiety.

OBJECTIVE: Anxiety disorders are the most common mental health conditions in the world, disproportionately affecting females and associated with significant morbidity. Neuroimaging can help us to understand the underpinnings of anxiety behaviors. The amygdala and its subnuclei have been strongly implicated in the neural circuitry of anxiety, with widespread connectivity with regions involved in emotional regulation and fear responses. The aim of this study was to investigate differences in resting-state functional connectivity of the amygdala and its subregions with levels of trait anxiety in a nonclinical population, and how this may differ between males and females. METHOD: 7 T resting-state functional magnetic resonance imaging scans from 40 individuals (50% female) and State-Trait Anxiety Inventory-Trait component scores were used with seed-based functional connectivity analyses. RESULTS: There were no differences in State-Trait Anxiety Inventory-Trait component scores between males and females (mean score ± SD, 30.2 ± 6.3), with no differences in resting-state functional connectivity observed between the basolateral and centromedial (CMA) subregions. However, increases in resting-state functional connectivity were identified with greater levels of anxiety with bilateral amygdala (combined basolateral and CMA; p < .05) and CMA (p < .01). Exploratory (p < .05) sex differences in this connectivity profile were also observed, with widespread reduction in amygdala and CMA connectivity related to trait anxiety in females compared to males. CONCLUSION: These results contribute to our understanding of neural circuitry involved in anxiety and highlight the importance of further research into sex-specific differences in larger studies with clinical anxiety, given the disproportionate prevalence of anxiety disorders between males and females. (PsycInfo Database Record (c) 2026 APA, all rights reserved).