Altered local gyrification index and corresponding functional connectivity in female depressed adolescents with suicide attempts and non-suicidal self-injury.

Background: Suicide attempts (SA) and non-suicidal self-injury (NSSI) are serious public health problems that frequently co-occur in adolescents females with major depressive disorder (MDD), yet their neurobiological distinctions remain unclear. Here, we sought to explore female adolescents' neural mechanisms via the local gyrification index (LGI) and resting-state functional connectivity (RS-FC) analysis.

Methods: We compared scale scores, LGI, and seed-based RS-FC among three groups of female adolescents: MDD with both NSSI and SA (SA + NSSI, n = 43), MDD with NSSI only (NSSI, n = 28), and healthy controls (HC, n = 27). Exploratory correlation analysis was applied to examine associations between the neuroimaging alterations and clinical symptom severity in depressed adolescents with SA and NSSI.

Results: Compared with the HC group, both SA + NSSI and NSSI groups showed significantly decreased LGI in the prefrontal cortex, including right rostral/caudal middle frontal gyrus (MFG), precentral gyrus and postcentral gyrus (po-CG.R), as well as left rostral MFG, precentral gyrus and opercular part of the inferior frontal gyrus. The brain regions with altered RS-FC (seeds based on po-CG.R and the rostral MFG.L) are mainly distributed in the anterior cingulate cortex, insula, postcentral gyrus, and occipital lobe (P < 0.05, FDR correction). Moreover, exploratory correlation analysis suggested no statistically significant correlations after FDR correction (α = 0.05).

Conclusion: Reduced cortical folding in postcentral and middle frontal gyri was found in both patient groups, alongside distinct functional connectivity, offering deeper neurobiological insights into SA and NSSI.