The mediating effect of distress tolerance on the relationship between stressful life events and suicide risk in patients with major depressive disorder

BACKGROUND: Despite widespread acknowledgment of the impact of stressful life events on suicide risk, the understanding of the psychological mechanisms underlying the relationship between stressful life events and suicide risk in major depressive disorder (MDD) remain unclear. This study aim to examine whether the distress tolerance mediates the relationship between the stressful life events and suicide risk in patients with MDD. METHODS: A cross-sectional study was carried out among 125 Chinese patients with MDD, mean age was 27.05 (SD=0.68) and 68.8% were females. The 17-item Hamilton Depression Rating scale (HAMD-17), the validated Chinese version of the Mini International Neuropsychiatric Interview (MINI) suicide module, Life Events Scale (LES) and Distress Tolerance Scale (DTS) were utilized to evaluate depressive symptoms, stressful life events, levels of distress tolerance, and suicide risk, respectively. Mediation analyses was used to test the mediation effect of distress tolerance on the relationship between stressful life events and suicide risk. RESULTS: The ratio of suicide risk in patients with MDD was 75.2%. Pearson correlation analysis showed that stressful life events were positively correlated with suicide risk(r=0.182, p<0.05). Stressful life events(r=-0.323, p<0.01) and suicide risk(r=-0.354, p<0.01) were negatively correlated with distress tolerance. Mediation analyses showed that the direct path from stressful life events to suicide risk was not significant (B= 0.012, 95% confidence interval (CI) [-0.017, 0.042]). Stressful life events affected suicide risk indirectly through distress tolerance (B= 0.018, 95% CI [0.007, 0.031]), and the mediating effect accounted for 60.0% of the total effect. CONCLUSION: Distress tolerance completely played a mediating role between stressful life events and suicide risk. Further suicide prevention and intervention strategies should focus on increasing levels of distress tolerance in patients with MDD.