Included is literature outlining of the Gatehouse Project. Distinguishing features of the project were its conceptual framework, implementation process, and evaluation design. The conceptual framework derived from attachment theory and focused on three aspects of the school social context: security, communication, and participation. Implementation was standardized around a survey of the school social environment, creation of a school-based action team, and the implementation of strategies matched to a school's profile of need. In addition, an early high school curriculum addressed the skills relevant to social functioning and emotional adjustment. The evaluation design was based on a cluster randomized trial involving 26 schools. It used follow-up of an individual cohort and repeat cross-sectional surveys to capture outcomes at an individual student and whole-school level.