Heart rate variability reactivity moderates the relationship between behavioral disinhibition and suicide attempts in mood disorders

J Affect Disord. 2026 Jul 20:122285. doi: 10.1016/j.jad.2026.122285. Online ahead of print.

ABSTRACT

BACKGROUND: Distinguishing suicide attempters from those with only ideation remains a major clinical challenge. This study investigated whether heart rate variability (HRV) reactivity, a marker of autonomic regulation, moderates the relationship between behavioral disinhibition and suicide attempts.

METHODS: We conducted a cross-sectional study of 61 inpatients with major depressive episodes, categorized into a Suicide Attempt group (SA, n = 23) and a Suicidal Ideation group (SI, n = 38). HRV was recorded during baseline and Go/No-Go task performance as a stress condition. We calculated HRV reactivity as the change in log-transformed high-frequency (HF) power from baseline to task. Logistic regression and interaction analyses were used to predict attempt status while adjusting for age, sex, and smoking.

RESULTS: The SA group was significantly younger and had more lifetime attempts. Groups did not differ in depression, self-reported impulsivity, or aggression (all p > 0.05). Unadjusted analyses showed the SA group had fewer omission errors (Median: 4.0 vs. 9.0, p = 0.014) and higher resting HRV-HF Power (181.0 vs. 63.5 ms², p = 0.033) compared to the SI group. However, these differences were attributable to younger age and became non-significant after adjustment. In exploratory interaction analyses, a significant effect emerged between Go/No-Go commission errors and HRV-HF reactivity (β = 0.12, p = 0.022). High commission errors were associated with suicide attempts only when coupled with blunted HRV reactivity.

CONCLUSION: Recent suicide attempt was associated with the coexistence of motor disinhibition and impaired HRV-HF reactivity. These exploratory findings highlight the importance of stress-related physiological reactivity over resting measures for risk stratification, providing preliminary proof-of-concept for differentiating high-risk subgroups.

PMID:42476345 | DOI:10.1016/j.jad.2026.122285