A large proportion of adults experiencing mental health problems do not receive care due to structural and attitudinal barriers. Mood Lifters (ML) is an evidence-based mental wellness program designed to reduce depression, anxiety, and stress symptoms. This study aims to extend the literature by examining whether ML reduces posttraumatic stress disorder (PTSD) symptoms, and if childhood trauma (CT) affects treatment outcomes. We hypothesized that ML will be effective for all symptoms. However, we predicted that those who endorse higher levels of CT would experience a diminished impact of ML on their symptoms. Graduate students and young professionals (N = 221), a demographic that is known to have greater mental health concerns, were randomly assigned to either the waitlist condition (n = 78) or the intervention condition (n = 143). Before and after ML participation, participants completed a series of questionnaires about their symptoms. ML reduced symptoms of PTSD for participants who received the intervention relative to the waitlist. Further, we also observed that while the overall regression models with CT predict posttreatment scores for all the clinical symptoms, the CT variable itself was predictive of only posttreatment anxiety. Unexpectedly, given that CT is often associated with less improvement, we found that those at all levels of CT experienced similar reductions in depression, anxiety and PTSD symptoms. Taken together, ML is a viable option to help people reduce depression, anxiety, stress, and PTSD regardless of the level of CT exposure. (PsycInfo Database Record (c) 2023 APA, all rights reserved).