Suicide risk among combatants : The longitudinal contributions of pre-enlistment characteristics, pre-deployment personality factors and moral injury

Background
Recent studies have shown that exposure to potentially morally injurious events (PMIEs) in deployment situations facilitates higher suicide risk among combatants. However, knowledge about pre-deployment factors that may moderate the negative contribution of PMIEs to suicide risk is rare. In this prospective study, we examined pre-enlistment characteristics and pre-deployment personality factors as possible moderators in the link between exposure to self, other, and betrayal dimensions of PMIEs and post-deployment suicide risk among Israeli active-duty combatants.

Methods
A sample of 335 active-duty Israeli combatants participated in a 2.5-year prospective study with three waves of measurements: T1—12 months before enlistment, T2—6 months following enlistment (pre-deployment), and T3—18 months following enlistment (post-deployment). Participants were assessed via semi-structured interviews of personal characteristics (e.g., cognitive index) at T1, validated self-report measures of personality factors for emotional regulation, impulsivity, and aggression at T2, and combat exposure, PMIEs, and suicide risk at T3 between 2019 and 2021.

Results
All three dimensions of PMIEs were significantly associated with higher suicidal risk among combatants. Importantly, higher levels of pre-deployment aggression and lower levels of emotional regulation moderated the association between PMIEs and suicide risk post-deployment, above and beyond pre-enlistment psychiatric difficulties and life events.

Conclusions
Our results highlight the roles of pre-deployment factors of emotional regulation and aggressiveness as possible moderators in the PMIEs-suicide risk link. These results emphasize the need for higher awareness of suicide risk among deployed combatants with low emotional regulation and high aggressiveness. Moreover, tailored interventions aiming to decrease emotional dysregulation and aggressiveness levels should be considered, as such interventions may help reduce suicide risk following combat-related transgressive acts.