Last year, the American Psychiatric Association for the first time added moral injury to its update of the Diagnostic and Statistical Manual of Mental Disorders (DSM).

To experience moral injury is to be forced to act in ways or to witness actions that contradict your most deeply held convictions.

You can sustain moral injury in one catastrophic event, like hurting an enemy combatant in an armed conflict you don’t believe is just. It can also appear after a slow crescendo of moral distress, as people who work in slaughterhouses or prisons report. Easily mistaken for depression, moral distress frequently presents as sadness or feeling like a bad person.

In his new book, Moral Injury: When Good Conscience Suffers in a World of Hurt, Michael Valdovinos, a former US military psychologist, points out this “unique kind of stress” overwhelmed medics early in the Covid-19 pandemic who felt they had betrayed their oath to do no harm, and in his own crisis of conscience while deployed to Afghanistan.