Children and adolescents who have been exposed to trauma have an increased risk of mental illness, including posttraumatic stress disorder and a wide range of other disorders. In fact, many develop broad psychopathology that challenges diagnostic boundaries. The mechanisms through which trauma exposure is linked with psychopathology are complex and include noncausal pathways and biological, psychological, and social factors. Targeting psychological processes with interventions, such as trauma-focused cognitive behavioral therapy, has been found to effectively treat posttraumatic stress disorder and cooccurring symptoms. However, most young people with trauma-related psychopathology do not access health services so they cannot benefit from evidence-based treatment. Future research that improves our understanding of broad trauma-related psychopathology and underlying mechanisms will reveal new targets for treatment and prevention interventions. To enable more trauma-exposed young people to benefit from these interventions, clinical implementation must be a priority and will require increased capacity and innovative approaches.