Alterations of amygdala volume and functional connectivity in migraine patients comorbid with and without depression

The comorbid relationship between migraine and depression has been well recognized, but its underlying pathophysiology is unclear. Here, we aimed to explore the structural changes of the amygdala and the abnormal functional connectivity of the centromedial amygdala (CMA) in migraineurs with depression.

High-resolution T1-weighted and functional magnetic resonance images were acquired from 22 episodic migraineurs with comorbid depression (EMwD), 21 episodic migraineurs without depression (EM), and 17 healthy controls (HC). Voxel-based morphometry and resting-state functional connectivity (rsFC) were applied to examine the intergroup differences in amygdala volume.

The bilateral amygdala volume was increased in the EMwD and EM groups compared with the HC group, but there were no differences between the EMwD and EM groups. The right CMA exhibited decreased rsFC in the left dorsolateral prefrontal cortex (DLPFC) in the EMwD group compared with the EM group, while rsFC increased between the CMA and the contralateral DLPFC in the EM group compared with the HC group. In addition, the EM group showed decreased rsFC between the left CMA and the left pallidum compared with the HC group.

Enlarged amygdala is an imaging feature of EM and EMwD. The inconsistency of rsFC between CMA and DLPFC between migraineurs with and without depression might indicate that decreased rsFC between CMA and DLPFC is a neuropathologic marker for the comorbidity of migraine and depression. The core regions might be a potential intervention target for the treatment of EMwD in the future.