Sex differences in brain metabolites of unmedicated depressed adolescents with non-suicidal self-injury: a proton magnetic resonance spectroscopy study.

Background: Gender differences in non-suicidal self-injury (NSSI) among adolescents with major depressive episodes (MDE) may exist, but the underlying neurobiological mechanisms remain unclear.

Methods: 171 unmedicated MDE adolescent patients with NSSI (NSSI group), 71 unmedicated MDE adolescent patients without NSSI (non-NSSI group), and 32 healthy controls (HC) were included. The 24-item Hamilton Depression Rating Scale (24-HDRS) was used to assess depressive symptoms. Bilateral metabolic ratios of N-acetyl aspartate (NAA) and choline-containing compounds (Cho) to creatine (Cr) in the prefrontal cortex (PFC), anterior cingulated cortex (ACC), lenticular nucleus (LN), and thalamus were obtained by proton magnetic resonance spectroscopy (1H-MRS) at 3.0 T.

Results: A significant interaction effect between biological sex and the group can be found in the Cho/Cr of the right thalamus, in which males with NSSI showed significantly lower Cho/Cr than those without (p = 0.01), and males had higher Cho/Cr of the right thalamus than females in the non-NSSI group (p = 0.002). A significant correlation between the risk of NSSI and the Cho/Cr of the right thalamus can only be found in male MDE adolescents (p = 0.002), instead of in females. The binary logistic regression showed a significant negative association between the Cho/Cr of the right thalamus and the risk of NSSI in males (p = 0.02).

Conclusions: There is a sex-specific association between the neurochemical metabolisms and the NSSI risk. The Cho/Cr of the right thalamus may increase the risk of NSSI in MDE male adolescents, which can be a specific biomarker for NSSI risk the in MDE male adolescents.