摘要
Major depressive disorder (MDD) is frequently accompanied by self-harm behaviors, including non-suicidal self-injury (NSSI) and suicide attempts (SA), which are important risk factors for suicide and poor clinical outcomes. Although neuroimaging studies have identified structural brain abnormalities related to suicidal behaviors in MDD, the neurobiological distinctions between NSSI and SA remain poorly understood. In particular, few studies have simultaneously compared MDD patients with NSSI, MDD patients with SA, and MDD patients without self-harm behaviors. Therefore, this study aimed to investigate gray matter volume (GMV) alterations and their associations with clinical symptoms in early adulthood (aged 18-30 years) MDD patients using voxel-based morphometry (VBM).
A total of 54 MDD patients with NSSI (MDD/NSSI), 68 MDD patients without NSSI (sMDD), 50 MDD patients with SA (MDD/SA), and 66 healthy controls (HCs) were included. VBM was used to examine GMV differences using high-resolution T1-weighted MRI scans. Age, sex, education, and intracranial volume were included as covariates. One-way ANOVA with Gaussian random field (GRF) correction was performed, followed by post-hoc t-tests. Correlations between GMV and clinical measures of depression (HAMD), anxiety (HAMA), and suicide risk (NGASR) were assessed.
Significant GMV differences were observed in the superior/middle frontal gyrus, superior frontal gyrus, bilateral caudate, superior/middle temporal gyrus, and middle cingulate gyrus (voxel-level p < 0.001, GRF corrected p < 0.05). Post-hoc analyses showed reduced GMV in the MDD/SA group compared with the MDD/NSSI group in several regions. However, supplementary GLM analyses indicated that NSSI-related characteristics showed more consistent independent associations with regional GMV, whereas SA history was not independently associated with GMV in any examined region. Correlations between GMV and clinical measures did not survive FDR correction.
MDD patients with NSSI and SA may exhibit distinct patterns of gray matter alterations; however, these differences likely reflect clinical heterogeneity across self-harm subgroups rather than SA-specific structural abnormalities. Supplementary analyses further suggest that NSSI-related characteristics show stronger independent associations with GMV than SA history. These findings highlight the importance of distinguishing self-harm subtypes in the neurobiological characterization of MDD. All results should be interpreted cautiously given the cross-sectional design and the lack of robust associations after multiple-comparison correction.
Not applicable.