Altered reward circuit in adolescents with non-suicidal self-injury: a study on subcortical volume and lateralization index

Purpose

This study aims to examine the structural characteristics of the reward circuit in adolescents with non-suicidal self-injury (NSSI), focusing on subcortical volume and lateralization index (LI). The objective is to shed light on the underlying mechanisms of NSSI within the reward circuits and provide structural evidence supporting its occurrence.

Methods

A total of 50 adolescents with first-episode NSSI and 33 healthy controls (HC) were enrolled. Clinical characteristics included the Self-Rating Anxiety Scale (SAS), Beck Scale for Suicidal Ideation (BSI), Brief Assessment of Cognition in Schizophrenia (BACS), and Ottawa Self-Injury Inventory (OSI). Subcortical volume segmentation was performed using Freesurfer software. LI quantified differences in left and right subcortical volume. Statistical analysis of clinical features, subcortical volume, and LI was performed using analysis of covariance, Wilcoxon rank-sum test, and independent sample t-tests. Pearson or Spearman correlation was used to explore relationships between subcortical volume or LI and clinical characteristics.

Results

The NSSI group had higher SAS scores compared to the HC group. BACS scores in the NSSI group were lower than in the HC group. Compared to the HC group, the NSSI group exhibited reduced volume in the left accumbens, along with an increased LI of the accumbens. In the NSSI group, left accumbens volume was positively correlated with BACS scores, and LI of the accumbens was negatively correlated with BACS scores.

Conclusion

This study discovered a decrease in the volume of the left accumbens in adolescents with NSSI, providing structural evidence that supports the involvement of reward circuits in NSSI among adolescents. The observed alterations in subcortical volume and LI suggest a potential vulnerability in the left hemisphere among adolescents with NSSI.