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 with major depressive disorder (MDD), especially in female adolescents. However, the neurobiological abnormalities between the two behaviors remain unclear. Here, we sought to explore female adolescents’ neural mechanisms via local gyrification index (LGI) and resting-state functional connectivity (RS-FC) analysis. Method We compared scale scores, LGI, and seed-based RS-FC indicators among three groups of female adolescents: MDD with NSSI and SA (SA+NSSI group, n = 43), MDD with NSSI alone (NSSI group, n = 28), and healthy control (HC group, n = 27). Exploratory correlation analysis was applied for exploring the relationship between the imaging changes and clinical symptom severity in depressed adolescents with SA and NSSI. Results Compared with the HC group, both the SA+NSSI group and the NSSI group had significantly decreased LGI in the prefrontal cortex, mainly distributed in the rostral middle frontal gyrus, caudal middle frontal gyrus, precentral gyrus, and postcentral gyrus (po-CG.R) on the right side of the brain, as well as the rostral middle frontal gyrus (rostral MFG.L), precentral gyrus, and opercular part of the inferior frontal gyrus on the left side of the brain. 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 Our findings primarily revealed reduced cortical folding in both the postcentral gyrus and middle frontal gyrus in the SA and NSSI groups, while their functional connectivity exhibited significant differences between the two groups. Such information could provide more comprehensive insights into neurobiological mechanisms in SA and NSSI.