P.2.a.023 Effect of polymorphisms in the tryptophan hydroxylase 2 gene on suicide risk in Korean with major depressive disorder

Abstract

This study investigated regional gray matter (GM) volume differences between suicide attempters and suicide non-attempters with major depressive disorder (MDD) and their relationship with psychological risk factors for suicidality.MDD patients with and without a suicide attempt history (n = 19 in each group) participated. The Hamilton Depression Rating Scale, Clinical Global Impression (severity subscale), Scale for Suicide Ideation (SSI), Risk-Rescue Rating (RRR), Beck Hopelessness Scale (BHS), Barrett Impulsivity Scale, Eysenck Personality Questionnaire, and Ways of Coping Checklist (WCCL) were administered. T1-weighted structural magnetic resonance imaging scans were acquired to evaluate changes in GM volume. Voxel-based morphometry was performed using the SPM 8 software package. Two-sample t-tests were used during second-level group comparison analysis; partial correlation analysis controlling for gender and age identified associations between regional GM volume and psychological measures.Suicide attempters exhibited significantly decreased GM volume in the left angular gyrus (p < 0.001, uncorrected) and right cerebellum (p < 0.001, uncorrected). GM volume in the left angular gyrus was inversely correlated with BHS scores (r = − 0.55, p < 0.01) and positively correlated with the Seeking Social Support subscale of the WCCL (r = 0.43, p < 0.01).These findings provide evidence of a neural basis of suicidal behaviors in MDD. In particular, reduced GM volume in the left angular gyrus may be a neurobiological marker of suicidality in depressed patients.