The Association Between Insular Subdivisions Functional Connectivity and Suicide Attempt in Adolescents and Young Adults with Major Depressive Disorder

Previous studies demonstrated the possible involvement of insula in suicide owing to depression. However, the function of insula in young depressed patients with suicide attempt (SA) remains to be revealed. This study aimed to explore the association between resting-state functional connectivity (FC) of insula and SA in young depressed patients. Fifty-eight adolescents and young adults with major depressive disorder, including 22 with a history of at least one SA (SA group) and 36 without a history of SA (NSA group) were scanned with a 3.0T functional magnetic resonance imaging system, and the resting-state functional magnetic resonance imaging data was extracted. Whole brain resting-state FC of insular subdivisions were compared between the two groups. Significantly increased FC of the left posterior insula with the orbital part of left inferior frontal gyrus, the right supplementary motor area and the bilateral paracentral lobule extending to the bilateral middle cingulate cortex was observed in the SA group compared with the NSA group. In addition, the orbital part of left superior frontal gyrus in the SA group exhibited significantly increased FC with the right posterior insula compared with the NSA group. However, no significant correlation was found between the insular subdivisions FC and different clinical variables in two groups. The present study highlighted the disruptions of the resting-state FC of the posterior insula with the orbitofrontal cortex and a series of motor cortices, and added incremental value to the knowledge of the neural mechanism underlying SA in young depressed patients.