Journal of Traumatic Stress xxxx 2019, 00, 1–11 Compassion Meditation for Posttraumatic Stress Disorder in Veterans: A Randomized Proof of Concept Study Ariel J. Lang, 1,2,3 Anne L. Malaktaris, 1,2 Pollyanna Casmar, 2,4 Selena A. Baca, 5 Shahrokh Golshan, 2,4 Timothy Harrison, 6 and Lobsang Negi 6 1 VA San Diego Center of Excellence for Stress and Mental Health, San Diego, California, USA 2 Department of Psychiatry, University of California San Diego, La Jolla, California, USA 3 Department of Family Medicine and Public Health, University of California San Diego, La Jolla, California, USA 4 VA San Diego Healthcare System, San Diego, California, USA 5 Veterans Medical Research Foundation, San Diego, California, USA 6 Department of Religion, Emory University, Atlanta, Georgia, USA There is considerable interest in developing complementary and integrative approaches for ameliorating posttraumatic stress disorder (PTSD). Compassion meditation (CM) and loving-kindness meditation appear to offer benefits to individuals with PTSD, including symptom reduction. The present study was a pilot randomized controlled trial of CM for PTSD in veterans. The CM condition, an adaptation of Cognitively-Based Compassion Training (CBCT R  ), consists of exercises to stabilize attention, develop present-moment awareness, and foster compassion. We compared CM to Veteran.calm (VC), which consists of psychoeducation about PTSD, rationale for relaxation, relaxation training, and sleep hygiene. Both conditions consist of 10 weekly 90-min group sessions with between-session practice assignments. A total of 28 veterans attended at least one session of the group intervention and completed pre- and posttreatment measures of PTSD severity and secondary outcomes as well as weekly measures of PTSD, depressive symptoms, and positive and negative emotions. Measures of treatment credibility, attendance, practice compliance, and satisfaction were administered to assess feasibility. A repeated measures analysis of variance revealed a more substantive reduction in PTSD symptoms in the CM condition than in the VC condition, between-group d =-0.85. Credibility, attendance, and satisfaction were similar across CM and VC conditions thus demonstrating the feasibility of CM and the appropriateness of VC as a comparison condition. The findings of this initial randomized pilot study provide rationale for future studies examining the efficacy and effectiveness of CM for veterans with PTSD. Despite considerable advances in the treatment of posttrau- matic stress disorder (PTSD), achieving wellness remains an elusive goal for many veterans. Barriers to complete recov- ery may include incomplete response to existing therapies (Steenkamp, Litz, Hoge, & Marmar, 2015) and low rates of engagement in empirically supported treatment (Haller, Myers, This work was supported by the National Center for Complementary and Integrative Health (NCCIH; R34 AT007936, PI Lang). Additionally, Dr. Malaktaris is supported by the Department of Veterans Affairs Office of Aca- demic Affiliations Advanced Fellowship Program in Mental Illness Research and Treatment, the Medical Research Service of the Veterans Affairs San Diego Health Care System, and the Department of Veterans Affairs San Diego Center of Excellence for Stress and Mental Health (CESAMH). The authors thank the members of the Independent Monitoring Committee, Drs. Stefan Hofmann, Lin Liu and Barbara Niles, for their contributions. The contents do not repre- sent the views of the U.S. Department of Veterans Affairs or the United States Government. Correspondence concerning this article should be addressed to Dr. Ariel Lang, VA San Diego Healthcare System, 3350 La Jolla Village Dr. (MC 111N1), San Diego, CA 92161. E-mail: ajlang@ucsd.edu Published 2019. This article is a U.S. Government work and is in the public domain in the USA. View this article online at wileyonlinelibrary.com DOI: 10.1002/jts.22397 McKnight, Angkaw, & Norman, 2016). As a result, there is con- siderable interest in exploring interventions that may comple- ment or serve as an alternative to existing approaches, including meditation (Lang et al., 2012). One meditative approach that has been previously studied for treatment of PTSD is loving- kindness meditation (LKM), which involves repetition of key phrases focused on the self and others (e.g., “May you be happy. May you be well. May you be free from harm.”) to cultivate a positive affective state. Based on positive initial re- sults, a randomized trial is currently under way to evaluate LKM (NCT01962714). Another way of cultivating positive af- fective states is by teaching compassion (karuna), which is differentiated from loving-kindness (metta) in Buddhist teach- ings (Buddhaghosa, 1975). Compassion meditation (CM) is a contemplative practice in which the practitioners’ thoughts are explored to develop a sense of common humanity and generate the heartfelt wish that the self and others be free of suffering. Thus, the key distinction from LKM is that CM brings aware- ness to one’s beliefs about the self and others and provides a framework within which to modify those thoughts. Both CM and LKM are believed to affect practitioners in ways that may 1