JPBS

Background Modified electroconvulsive therapy (MECT) can rapidly eliminate suicide attempts in patients with suicidal depression. However, no study has investigated the neural mechanisms by which MECT eliminates suicide attempts. Currently, we conducted a study to explore the potential mechanisms by which MECT eliminates suicide attempts in patients with suicidal depressive episodes. Methods Four drug-naive patients with suicidal depressive episode underwent structural and resting-state functional magnetic resonance imaging scanning before and after MECT treatment. The voxel-based morphometry (VBM) and functional connectivity density mapping(FCDM) methods were used to analyze the imaging data. The gray matter volume (GMV) and resting-state global functional connectivity density (rs-gFCD) were used to evaluate the structural and functional alterations, respectively, that occurred subsequent to MECT. Results The VBM analysis revealed that MECT induced a GMV increase that was primarily localized to the left dorsolateral prefrontal cortex and bilateral thalamus. The FCDM analysis revealed that MECT induced an rs-gFCD decrease that was mainly localized in the left medial superior frontal gyrus and bilateral orbitofrontal cortex. No overlap existed between brain regions that exhibited structural and functional alterations. Conclusion The structural and functional alterations subsequent to MECT were mainly located in the brain regions that are related to the suicide attempts in suicidal depressive patients. The brain regions that exhibited structural alterations did not overlap with those that exhibited functional alterations, which suggests that the structural and functional alterations contributed independently to the efficacy of MECT in the elimination of suicide attempts in patients with suicidal depression.

Suicide attempt; depression; modified electroconvulsive therapy; gray matter volume; functional connectivity density