Brain Functional Network Alterations in Adolescents With Major Depressive Disorder and Suicidal Attempt: A Resting-State fMRI Study

Background: The neurobiological mechanism underlying suicidal attempts in depressive adolescents remains unknown. This study investigated brain functional network changes in adolescent depression with suicidal attempt. Methods: First episode, treatment naïve adolescent patients with depression and suicidal attempts, and healthy adolescents matched for age and sex were enrolled. Resting-state functional magnetic resonance images were obtained and whole-brain functional matrices were constructed to analyze functional connectivity differences between the two groups. The graph theory method was used to analyze topological alterations in brain regions with altered functional connectivity. Correlations were analyzed between functional parameters and clinical characteristics. Results: A total of 47 patients and 33 healthy adolescents were included. Depressed adolescents with suicidal attempts showed lower functional connectivities than did healthy controls in critical brain regions, mainly located in the sensorimotor network, default mode network, cognitive control network, visual network and cerebellum. Graph theory analysis revealed a decreased degree centrality in the right precentral gyrus of patients. Correlation analyses identified a negative association between depressive symptom severity and functional connectivity in the left supplementary motor cortex-inferior parietal lobule in the patient group. Conclusions: This study revealed functional abnormalities in depressed adolescents with suicidal attempts in critical brain networks that were responsible for emotional regulation, cognitive process and behavioral controls, and suggested critical neurobiological evidence of suicidality in depression.