Amy Amidon has listened to war stories on a daily basis for almost a decade.

As a clinical psychologist at the Naval Medical Center in San Diego, she works with a multi-week residential program called OASIS, or Overcoming Adversity and Stress Injury Support, for soldiers who have recently returned from deployments. Grief and fear dominate the majority of the conversations in OASIS: Amidon regularly hears participants talk about improvised explosive devices claiming the lives of close friends; about flashbacks of airstrikes pounding cities to rubble; about days spent in 120-degree desert heat, playing hide and seek with a Taliban enemy. Many veterans in the program are there seeking treatment for post-traumatic stress disorder.

But many of Amidon’s patients talk about another kind of trauma, a psychic bruise that, unlike PTSD, isn’t rooted in fear. Some of these soldiers describe experiences in which they, or someone close to them, violated their moral code: hurting a civilian who turned out to be unarmed, shooting at a child wearing explosives, or losing trust in a commander who became more concerned with collecting decorative pins than protecting the safety of his troops. Others, she says, are haunted by their own inaction, traumatized by something they witnessed and failed to prevent. In 2012, when the first wave of veterans was returning from the Middle East, these types of experiences were so prevalent at OASIS that “the patients asked for a separate group where they could talk about the heavier stuff, the guilt stuff,” Amidon says. In January 2013, the center created individual and group therapy opportunities specifically for soldiers to talk about the wartime situations that they felt went against their sense of right and wrong. (Rules of engagement are often an ineffective guide through these gray areas: A 2008 survey of soldiers deployed at the beginning of the conflict in Iraq found that nearly 30 percent of the soldiers in each group encountered ethical situations in which they were unsure how to respond.)

Experts have begun to refer to this specific type of psychological trauma as moral injury. “These morally ambiguous situations continue to bother you, weeks, months, or years after they happened,” says Shira Maguen, the mental-health director of the OEF/OIF Integrated Care Clinic at the San Francisco Veterans Affairs Medical Center and one of the first researchers to study the concept. Examples of situations that might precipitate moral injury are betrayals by those in leadership roles, within-rank violence, inability to prevent death or suffering, and hurting civilians. Sometimes it co-exists with PTSD, but moral injury is its own separate trauma with symptoms that can include feelings of shame, guilt, betrayal, regret, anxiety, anger, self-loathing, and self-harm. Last year, a study published in Traumatology found that military personnel who felt conflicted about the “rightness” or “wrongness” of a combat situation were at an increased risk for suicidal thoughts and behavior afterwards, compared with their peers who didn’t have that same sense of ambiguity. The main difference between the two combat-induced traumas is that moral injury is not about the loss of safety, but the loss of trust—in oneself, in others, in the military, and sometimes in the nation as a whole.

Although some have proclaimed it the “signature wound of today’s veterans,” moral injury has been around for as long as war itself. Ajax, the titular warrior in Sophocles’s tragedy, ultimately commits suicide after spiraling into shame for slaughtering innocent animals. Soldiers’ diaries from the Civil War expressed guilt and paranoia for feeling responsible for atrocities, and World War II airmen wrote in their journals about their remorse for bombing civilians. In Tim O’Brien’s iconic book about the Vietnam War, The Things They Carried, the narrator confessed: “I watched a man die on a trail near the village of My Khe. I did not kill him. But I was present, you see, and my presence was guilt enough.”

“There are a whole lot of moral compromises that people might not have been prepared to make.”

Some researchers believe that susceptibility to moral injury may be linked to cognitive development: Soldiers, often in their late teens when they first deploy, may not yet be equipped with the cognitive skills to effectively process moral ambiguity. “Most young adults think in black-and-white in terms of moral concepts, because they are still developmental adolescents and not always able to think in nuanced terms,” says Nancy Sherman, a professor of philosophy at Georgetown University and the author of Afterwar: Healing the Moral Wounds of Our Soldiers. “They also train with set ideals that encourage black-and-white thinking: Never leave a buddy behind, bring everyone home, minimize collateral damage. But as missions get harder and you encounter things like insurgency in civilian populations, you can’t do all those things at once. You can’t even do most of those things well. So there are a whole lot of moral compromises that people might not have been prepared to make.”

Identifying moral injury can be tricky for two reasons: First, it’s easily mistaken for PTSD, which shares many of the same symptoms. And second, because veterans may feel too ashamed to talk about their moral infractions, therapists might not even know to look for the signs of moral injury at all, says Joseph Currier, an assistant professor of psychology at the University of South Alabama. To help therapists better understand how to diagnose the condition, he and several colleagues have developed a 20-item questionnaire that screens patients for moral injury, asking patients to rate their agreement with statements like “I did things in war that betrayed my personal values” and “I made mistakes in the war zone that led to injury and death.”

“Most other scales tap into life-threat traumas, where the predominant emotion is going to be fear,” Currier says. “We are learning that serving in war entails a far more diverse set of stressors, and getting at the right one can help therapists create a better and more accurate treatment for patients.”

Even after diagnosis, however, therapists may have a hard time figuring out an effective treatment plan for moral injury, which requires a different approach that PTSD. “Current interventions for PTSD do well when trauma is fear- and victim-based, but not all moral injury fits under this umbrella,” says Brett Litz, the director of the Massachusetts Veterans Epidemiological Research and Information Center. In 2007, Litz and his colleagues developed a moral injury-specific treatment they call “adaptive disclosure,” a multi-session program rooted in cognitive behavioral therapy. The program is designed to help veterans accept their infractions, rather than erase them from memory or explain them away. Veterans also learn how to disclose experiences to others in a safe space without feeling guilt or shame.

Adaptive disclosure is designed as a gradual progression, with each 90-minute session building upon the last. The first meeting is more instructive than participatory, a sort of “Moral Injury 101”: Therapists explain the meaning of the term, the different kinds of situations that cause it, and the negative impact it can have on the psyche and relationships. In the sessions that follow, veterans begin to share their stories, receive encouragement from peers, and write letters, either apologizing to the person they believe they wronged or confiding in a benevolent moral authority figure (like a trusted friend or spiritual leader). Though the veterans aren’t required to send the notes, the written exercise “helps veterans get in touch with their compassionate side, a part of them they might have lost,” says Amidon, who uses adaptive disclosure in OASIS.

Amidon believes the program’s success stems from its emphasis on moving forward. “In order to heal from shame, guilt, and betrayal, you have to own it. [The veterans] first own it themselves, then they own it with a peer group that understands what they’ve gone through and isn’t going to judge,” she says. “A key part of moral repair is acknowledging what you’ve done, and the more people you can acknowledge that with, the more safe people, the more you are going to heal from it.” Preliminary research seems to support this idea: A small 2012 study of 44 marines, published in the journal Behavioral Therapy, found that adaptive disclosure was linked to reduced symptoms of PTSD and depression.

Back in San Francisco, Maguen and her colleagues have recently finished preliminary trials for a new program, the Impact of Killing Treatment (IOK). Maguen, who focuses on the effects of combat killing on mental health, conducted several studies with veterans of Vietnam and the Gulf War, as well as those recently back from deployment in Iraq, and found that killing was strongly linked to later depression, alcohol abuse, anger, and relationship problems. “We’ve done many focus groups and veterans have told me that nothing really prepares you for killing in war, even with the training,” she says.

A defining characteristic of IOK is working on self-forgiveness, an exercise she believes is crucial to moral repair. One of the strategies Maguen employed in the IOK trials was the reevaluation of responsibility. “We have a lot of people that take full ownership of what happened, but when you break it down, you might see that there were a lot of aspects in the situation at play, like the environment, the leadership, the ambiguous circumstances,” she says. “If you realize you only played a small role, as opposed to bearing full responsibility, you can see how that would really change someone's attitude about what they did.”

“Nothing really prepares you for killing in war, even with the training.”

However, she adds, not all responsibility can be allocated away, and sometimes the process becomes more about acceptance than contextualization. “We don’t try to downplay responsibility. If someone feels responsible, then it doesn’t feel supportive to change his or her opinion,” she says. “We work with veterans to understand where they are stuck in moving forward and work on understanding, ‘Okay, this is what you did, you know that it went against your morals and values, yet here is your life in front of you.’”

Another key part of treating moral injury is renewing veterans’ ability to trust themselves and others. To put this into practice, Peter Yeomans, a psychologist at the Philadelphia V.A. Medical Center who runs moral-inury group therapy for Vietnam veterans, asks them to perform several random acts of kindness each week. “An essential principle in behavioral psychology is that if you can change the way you act, you can then change how you think and feel,” he explains. “You practice kindness and service, even if you don't feel kind. You practice trusting others even when you feel untrusting. Gradually, these behaviors will lead to change.”

For veterans whose sense of morality is derived from religious beliefs, faith may plays a role in healing as well. Past studies have found that religious or spiritual practices may be an effective tool in helping people cope with trauma or forgive themselves after an act of wrongdoing. Religious texts may also be a helpful part of the healing process for some veterans, Currier says: “There are stories of people going existential crises and surviving them, so they offer cases of moral repair all over the place.”

But healing isn’t just confined to the individual. Emotions that guide morality, Currier explains, are rooted in social relationships: “The function of guilt is to reconcile a potentially damaged social bond, whereas with shame, the reaction is to withdraw so the social group can preserve its identity,” he says. For many veterans, therefore, recovery from moral injury depends in part on the civilian communities to which they return. “A part of feeling betrayed or distrusted or guilty by the practices of war is feeling alienated. It’s feeling like you can’t share your experiences because people will judge you or won’t understand,” Sherman says. “You retreat within yourself, and that’s very damaging.” Undoing that damage, she explains, is a two-step process: Veterans have to be willing to share, and civilians have to be willing to listen without judging.

Many outreach groups have already initiated community dialogue. Veteran-Civilian Dialogue is a public event held every six weeks in New York City, bringing together service members and civilians to discuss how war has affected their lives. In each session, a designated veteran and civilian lead the group discussion together, often incorporating drama, music, and poetry. And at Syracuse University, The Moral Injury Project is an interdisciplinary organization that connects local veterans, faculty, chaplains, researchers, and community members through events like academic panels, art exhibits, and literary readings. “It’s incredible to have these men and women in the same room, approaching moral injury from different angles,” says Andrew Miller, the project coordinator and a United States Army veteran.

“Prior societies and civilizations had healing and cleansing rituals that everyone would engage in after returning from battle. So even though only a small segment of people were in combat, there was an assumption that ‘we are all in this together,’” Currier says. “Unless we as society can handle the tragic aspects of coming home, then the veterans are going to be the ones forced to carry all the pain.”