Effective dissemination of treatment methods requires not only training in the high-profile interventions, but also in the case conceptualization and treatment planning skills that facilitate use of the interventions. In a series of six studies, we tested one training module with 303 para-professionals and mental health professionals in a variety of training settings and five countries. Participants completed self-report ratings in response to a scenario of a challenging acting-out client, both before and after completing a trauma-informed case formulation exercise. The training intervention led participants to report decreased distress while considering challenging work-related scenarios, increased empathy and caring towards challenging clients, and increased comfort and confidence in their helping roles with those clients. In the final two studies, a trauma-informed treatment planning module was added, which yielded additional benefit. At follow-up participants reported that the effects persisted and led to improved behaviors towards the clients. Such empirical validation of training methodologies can lead to more reliably effective dissemination.