Dr. John Steven March reviews two incontrovertible and irreversible trends that are gradually shifting intervention development for psychiatric disorders from a focus on adult organisms to a focus on developing organisms. First, epidemiological data indicate that the great majority of mentally ill adults were first mentally ill as children, and that this effect is evident as early as two years of age. Second, recent advances in translational developmental neuroscience have shown that mental illness of all types can be referenced directly to the developing central nervous system and its interactions with the environment. The knowledge that mental disorders are early onset trajectory-based brain illnesses has enormous implications for the nature and organization of how we understand interventions for psychiatric patients of all ages. Put succinctly, to pre-empt, prevent, and cure psychiatric disorders, it will be necessary to translate insights about driver pathways for mental illness into drugable targets that directly reflect key neurodevelopmental processes that form trajectories of atypical as contrasted to typical development.