Impact of Killing in War: A Randomized, Controlled Pilot Trial

OBJECTIVE: The purpose of this pilot study was to test the effectiveness of Impact of Killing (IOK), a novel, cognitive-behavioral treatment (CBT) aimed at reducing mental health symptoms and functional impairment. METHOD: Participants were 33 combat Veterans with a posttraumatic stress disorder (PTSD) diagnosis who had completed trauma-focused psychotherapy and reported distress regarding killing or feeling responsible for the deaths of others in war. Veterans were randomized to either IOK treatment or a 6-week waitlist condition, after which Veterans could receive IOK. IOK is a 6- to 8-session, weekly, individual, CBT, lasting 60-90 minutes, and focused on key themes, including physiology of killing responses, moral injury, self-forgiveness, spirituality, making amends, and improved functioning. RESULTS: We found that compared to controls (N = 16), the IOK group (N = 17) experienced a significant improvement in PTSD symptoms, general psychiatric symptoms, and quality of life functional measures. Veterans who received IOK reported that the treatment was acceptable and feasible. CONCLUSION: These results provide preliminary evidence that Veterans can benefit from a treatment focused on the impact of killing after initial trauma therapy.