Moral Injury and Suicide: A Systematic Review of Mediators and Moderators

"Moral injury" (MI) describes the psychosocial-spiritual distress that may follow events that involve deep violations of right and wrong (i.e., potentially morally injurious events [PMIE]). Little is known about why MI seems to elevate risk for suicidal thoughts and behaviors (STB). This review aims to synthesize the existing research on mechanisms of the association (i.e., mediators and moderators) between PMIE/MI/moral distress and STB.

We conducted a PRISMA/PROSPERO systematic review (ID# CRD42024524601; last search July 2025). Data quality were assessed with two validated bias assessments.

Searches across 23 databases identified 1363 studies, 25 of which met inclusion criteria (i.e., empirical analysis in a peer-reviewed publication on mediators or moderators of the association between PMIE/MI/moral distress and STB). The studies had a combined total of 20,832 participants including military and healthcare professionals in the United States, Israel, and China. Mediators and moderators were classified as internalizing psychopathology (n = 10; e.g., depression, post-traumatic stress disorder [PTSD]), externalizing psychopathology (n = 1; e.g., aggression), social/environmental factors (n = 10; e.g., social connectedness, belongingness), guilt/shame (n = 5), and meaning making/mindfulness (n = 7). The combined effect of depression, anxiety, and PTSD explained the most variance in STB. Most studies received an "acceptable" quality rating.

Psychological pain, including psychopathology and shame, and impaired social functioning may confer the greatest risk for STB. Interventions addressing comorbidities and social functioning may be critical in STB prevention among those exposed to PMIEs.