NEURAL SIGNATURES OF VMPFC–AMYGDALA CONNECTIVITY UNDERLYING LONGITUDINAL ANXIETY DYNAMICS AND POSITIVE AFFECT STABILITY

Disruptions in connectivity between the ventromedial prefrontal cortex (vmPFC) and the amygdala are consistently linked to heightened anxiety and impaired affect regulation. The basolateral amygdala (BLA) integrates emotional input with executive regions to modulate negative emotions, whereas the centromedial amygdala (CMA) is primarily involved in automatic threat responses and stress adaptation. The vmPFC also differentially modulates the left and right amygdala, with greater involvement of the left in negative emotion regulation. This study examined how structural and functional amygdala connectivity relates to emotional dynamics, focusing on BLA and CMA subdivisions and sex-specific vmPFC–amygdala associations. Multimodal neuroimaging (structural MRI, resting-state fMRI, and DTI) was collected at baseline, and ecological momentary assessment (EMA) via smartphone measured anxiety-related processes and happiness. Regarding EMA measures, trait (6 months), state (1 month), and instability indices—Probability of Acute Change (PAC), Mean Square Successive Differences (MSSD), and emotional inertia—were derived. Canonical correlation analyses tested links between EMA variables and connectivity measures in 165 participants. Results showed that, in men only, stronger structural vmPFC–left amygdala connectivity predicted higher PAC and lower anxiety inertia. In women, happiness variability (MSSD) was predicted by functional vmPFC–right amygdala connectivity, with stronger connectivity linked to lower variability, particularly driven by the CMA. Overall, findings highlight sex-specific vmPFC–amygdala pathways in anxiety and affect regulation and support integrating multimodal connectivity with longitudinal affect data to inform personalized emotional health interventions.