The Impact of Killing (IOK) mental health treatment for moral injury: U.S. military veteran perspectives on acceptability, fit, and impact.

Moral injury related to killing in war significantly increases military veterans' risk for psychosocial problems and suicide, yet veterans largely lack access to interventions that address moral suffering. This article presents findings from semistructured qualitative interviews with 40 veterans who completed the Impact of Killing (IOK) mental health treatment for military moral injury. Interviews assessed (a) whether the IOK treatment was acceptable to veterans and met their needs, (b) changes in veterans' lives and psychological well-being resulting from IOK participation, and (c) suggestions for improving IOK. Using rapid analysis procedures, we identified several themes relevant to intervention acceptability, impact, and fit. Veterans found IOK to be intense and emotionally demanding but often felt that it yielded a fuller understanding of their past actions and greater compassion for themselves. After IOK, veterans described positive changes in their relationships and greater engagement in meaningful life activities. However, veterans often felt the treatment ended too soon and wanted ongoing, formal support to continue the work of IOK. In summary, IOK is a promising approach to the treatment of moral injury related to killing in war. Participants found IOK to be intense, demanding, and even painful, yet it also enabled many to begin changing their lives in positive and meaningful ways. Participants saw IOK as the start, rather than the end, of their healing journey. (PsycInfo Database Record (c) 2026 APA, all rights reserved).