Buffering and Direct Effect of Posttraumatic Growth in Predicting Distress Following Cancer Ashley Wei-Ting Wang Hunter College, City University of New York Cheng-Shyong Chang, Shou-Tung Chen, and Dar-Ren Chen Changhua Christian Hospital, Changhua, Taiwan Fang Fan South China Normal University Charles S. Carver University of Miami Wen-Yau Hsu National Chengchi University Objective: Evidence regarding post traumatic growth (PTG) as a predictor of future reductions in distress has been inconclusive. The purpose of this study was to examine this relationship in a multiple- observation prospective study, to provide a more rigorous test of prediction over time. This longitudinal study extended previous work by taking into account perceptions of vulnerability and explored the buffering role of PTG on the links between vulnerability and psychological distress. We also explored whether individual differences in demographic and medical characteristics moderate the relationship of interests. Method: Participants were 312 Taiwanese women (M age = 46.7 years) who underwent surgery for breast cancer. Measures of PTG, perceived vulnerability, and distress were assessed at Day 1 and 3, 6, 12, and 24 months after surgery. Hierarchical linear modeling was used to investigate whether PTG and vulnerability and their interaction predicted distress over time. Results: A significant direct effect of PTG on distress was found: higher PTG was followed by lower distress. Analysis also yielded a significant buffering effect of PTG on vulnerability leading to distress. However, this effect was moderated by type of surgery. The buffering effect of PTG occurred only among women having mastectomy. Conclusions: We conclude that PTG tends to lead to less psychological distress overall but particularly so in a high impact context. Keywords: posttraumatic growth, vulnerability, distress, hierarchical linear modeling, breast cancer Receiving a breast cancer (BCa) diagnosis is a frightening and unexpected event that challenges an individual’s fundamental be- liefs and leads to confrontation of one’s mortality and the inevi- tability of death (Tallman, Altmaier, & Garcia, 2007). On the other hand, survivors often express positive changes or posttraumatic growth (PTG), as a result of the cancer experience (Sears, Stanton, & Danoff-Burg, 2003; Taylor, 1983). A number of theorists have analyzed PTG through the lens of Lazarus and Folkman’s (1984) model of stress and coping. PTG has been characterized as being a self-enhancing appraisal, which protects people from the detrimental effects of cancer stress (Tay- lor, 1983). PTG could also be a coping mechanism by itself (Affleck & Tennen, 1996), working as a meaning-making process to either construe something good from bad (assimilation) or rebuild an assumptive world that was shattered by the cancer experience (accommodation; Davis, Nolen-Hoeksema, & Larson, 1998; Park & Folkman, 1997). Such successful coping efforts may create a positive transformation (Tedeschi & Calhoun, 2004) or a transition to being a healthy person again (Brennan, 2001). Al- though it once was debated whether PTG is a coping process or an outcome (for reviews, see, Zoellner & Maercker, 2006), many now believe that PTG can be both a coping mechanism and a coping outcome (e.g., Affleck & Tennen, 1996; Tedeschi & Calhoun, 2004; Zoellner & Maercker, 2006). As PTG is generally seen as a healthy adjustment effort, an intriguing question is whether PTG is related to better psycholog- ical well-being. Past research linking PTG to psychological dis- tress in cancer patients has had inconsistent results, with some Ashley Wei-Ting Wang, Department of Psychology, Hunter College, City University of New York; Cheng-Shyong Chang, Division of Hematology-Oncology, Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan; Shou-Tung Chen and Dar-Ren Chen, Comprehensive Breast Cancer Center, Changhua Christian Hospital, Changhua, Taiwan; Fang Fan, Center for Studies of Psychological Appli- cation and School of Psychology, South China Normal University; Charles S. Carver, Department of Psychology, University of Miami; Wen-Yau Hsu, Department of Psychology and Research Center for Mind, Brain, and Learning, National Chengchi University. This study was funded by National Science Council Grant 99-2410-H- 004-074-MY3. Correspondence concerning this article should be addressed to Wen- Yau Hsu, Department of Psychology, National Chengchi University, 64, Sec.2, Zhinan Road Wenshan District, Taipei City 11605 Taiwan (R.O.C). E-mail: hsu@nccu.edu.tw This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. Health Psychology © 2017 American Psychological Association 2017, Vol. 36, No. 6, 549 –559 0278-6133/17/$12.00 http://dx.doi.org/10.1037/hea0000490 549