Neuroanatomical signatures of suicide attempts in major depressive disorder

Suicide attempts are among the most severe outcomes in major depressive disorder (MDD), yet the underlying neuroanatomical substrates remain incompletely understood. Prior imaging studies have yielded inconsistent findings, likely reflecting methodological heterogeneity and a reliance on single-modality approaches.

In this study, we adopted a multimodal MRI framework to examine structural brain differences with suicide attempts in MDD. Seventy patients with MDD (35 with and 35 without a history of suicide attempts) and 35 healthy controls underwent structural and diffusion MRI. We performed cortical thickness analysis, white matter integrity analyses, and subcortical volume and shape analysis.

Compared to non-attempters and controls, suicide attempters exhibited significantly thinner cortex in frontoparietal and limbic regions, including the left primary somatosensory cortex, right orbitofrontal cortex, and right anterior intraparietal area. White matter analysis revealed increased mean diffusivity and decreased axial diffusivity in the cingulum, corticospinal tract, and anterior thalamic radiation among attempters. Subcortical volume was significantly reduced in the right hippocampus, thalamus, and left pallidum in attempters compared to non-attempters and controls. Shape analysis further revealed inward deformation of the right putamen in suicide attempters.

Patients with MDD and a history of suicide attempts demonstrate converging structural abnormalities across cortical, subcortical, and white matter domains. These alterations, particularly in regions implicated in emotion regulation and reward processing, may serve as neuroanatomical signatures of suicide risk. Our findings support the potential utility of multimodal neuroimaging biomarkers in stratifying suicide vulnerability in MDD.