This article considers the implications of theory and research in developmentalpsychopathology for existing and emerging social policy concerning treatment of child andadolescent psychopathology. Based on the concept that all psychopathology is a process, fourcore principles of a developmental psychopathology perspective are discussed. In turn, each isapplied to an evaluation of policy issues with implications for intervention, including mental healthparity, treatment guidelines, mental health reimbursement, and level of intervention. It isconcluded that social policy on treatment must be based on an empirically supported theory ofdevelopmental psychopathology and on evidence-based interventions that link treatments topathogenic processes.