Ramos, CatarinaCosta, Pedro AlexandreRudnicki, TâniaMaroco, Ana LúciaLeal, IsabelGuimarães, RaquelFougo, JLTedeschi, Richard G.2018-06-272018-06-272018Psycho-Oncology, 27(1), 258-264. Doi: 10.1002/pon.45011057-9249http://hdl.handle.net/10400.12/6463Objective: This longitudinal study tested the effectiveness of a group intervention designed to facilitate posttraumatic growth (PTG). Methods: Sample consisted of 205 women diagnosed with non‐metastatic breast cancer who were either assigned to an intervention group (n = 58) or to a control group (n = 147). PTG, challenge to core beliefs, and rumination (intrusive and deliberate) were assessed at baseline (T1), at 6 months (T2), and at 12 months after baseline (T3). Results: Results from the Latent Growth Modeling suggested that participants from the intervention group have higher levels of PTG. The challenge to core beliefs and the intrusive rumination have a moderator role on PTG, since group intervention is also linked to the enhancement of both variables. Conclusions: Participation in the intervention group increase PTG. Challenge to core beliefs and intrusive rumination are improved by group intervention, which to a certain extent facilitate PTG.engBreast cancerCancerChallenge to core beliefsGroup interventionOncologyPosttraumatic growthRuminationjournal article10.1002/pon.4501