For military personnel and veterans who carry the psychological consequences of having killed during war, a new study published in JAMA Psychiatry suggests that a specialized psychotherapy may improve daily functioning as well as trauma-related symptoms. The findings indicate that individuals who received an intervention identified as IOK experienced greater gains in work or school performance, social relationships, and home or family life than participants who received PCT, a comparison treatment, at the end of therapy.
The research addresses a form of distress that can remain hidden behind more familiar diagnoses such as post-traumatic stress disorder. Some service members struggle with what researchers describe as moral injury, a deep psychological response that can arise when a person believes they have violated their core moral values or been forced to participate in actions that conflict with those values. Killing during war may produce guilt, shame, grief, anger, spiritual conflict, or a lasting sense of disconnection from other people.
Both treatment groups improved on standardized measures of psychosocial functioning, according to the study summary. These changes were assessed using the World Health Organization Quality of Life-BREF, commonly known as the WHOQOL-BREF, and the Sheehan Disability Scale, or SDS. The WHOQOL-BREF evaluates several dimensions of quality of life, including psychological health, social relationships, physical functioning, and the surrounding environment. The SDS focuses more directly on how symptoms interfere with work or school, social life, and family responsibilities.
The stronger SDS improvements among IOK participants are particularly significant because symptom reduction does not always translate into restored everyday functioning. A person may report fewer intrusive memories or less severe anxiety while continuing to avoid relationships, struggling to maintain employment, or feeling unable to participate in family life. By measuring these practical domains, the study examined whether treatment could affect the broader consequences of combat-related distress rather than focusing only on clinical symptoms.
Participants who received IOK also reported improvements in PTSD symptoms and symptoms associated with moral injury. PTSD can involve intrusive memories or nightmares, emotional and physical reactions to reminders of trauma, avoidance, negative changes in mood and beliefs, and heightened alertness. Moral injury is not identical to PTSD, although the two can overlap. Its symptoms may center more heavily on guilt, shame, self-condemnation, betrayal, loss of trust, or difficulty finding meaning after morally painful experiences.
The apparent benefit of IOK may reflect the importance of addressing the meaning that individuals assign to traumatic events. Conventional trauma therapies often focus on fear conditioning, avoidance, and the processing of frightening memories. A treatment designed for moral injury may also need to examine responsibility, intent, values, forgiveness, grief, identity, and the possibility of rebuilding a coherent moral framework. These issues can be especially difficult when a person believes that no explanation can undo what happened.
The comparison with PCT provides a way to distinguish the effects of a targeted intervention from the general benefits of receiving professional care. Participants in both groups improved, suggesting that therapeutic contact itself may have helped reduce distress and strengthen functioning. However, the greater gains observed in the IOK group across several areas of the SDS suggest that a treatment tailored to killing-related distress may offer advantages beyond nonspecific support or symptom monitoring.
The findings do not mean that every person exposed to combat killing will develop moral injury, PTSD, or lasting impairment. Responses to war are shaped by the circumstances of the event, personal beliefs, unit culture, social support, previous trauma, and the availability of meaningful recovery environments. Nor do the results establish that IOK will be equally effective for all veterans or service members. Further research will be needed to clarify which patients benefit most, how durable the improvements are, and whether the treatment can be delivered effectively in military and veterans’ health systems.
Still, the results highlight a growing shift in trauma research toward outcomes that matter outside the clinic. Recovery is not limited to lower scores on a psychiatric questionnaire. It may also mean returning to education or employment, reconnecting with friends, participating in family life, and developing a less destructive relationship with one’s own memories. For people distressed by acts committed in war, therapies that directly address moral conflict could become an important part of comprehensive mental health care.
The study’s authors include corresponding author Shira Maguen, PhD, of the Mental Health Service at the San Francisco Veterans Affairs Health Care System. The work was published in JAMA Psychiatry under the digital object identifier 10.1001/jamapsychiatry.2026.2307. Full details about the investigators, treatment protocols, participants, funding, and potential conflicts of interest are available in the published article.
Subject of Research:
Psychotherapy for moral injury, post-traumatic stress disorder, and psychosocial impairment associated with killing during war.
Web References:
JAMA Psychiatry article DOI: https://doi.org/10.1001/jamapsychiatry.2026.2307
References:
Maguen S, et al. Study of IOK compared with PCT for individuals experiencing distress related to killing in war. JAMA Psychiatry. DOI: 10.1001/jamapsychiatry.2026.2307.
Keywords:
Moral injury, post-traumatic stress disorder, PTSD, military mental health, veterans, psychotherapy, psychosocial functioning, WHOQOL-BREF, Sheehan Disability Scale, combat trauma, war, family functioning, social relationships.
