Research has linked exposure to abuse, neglect and other forms of severe adversity in childhood to a wide range of mental and physical diseases and disorders. Can understanding this make a profound change in the way we prevent illness? In the wake of the Newtown tragedy, a complex mental health debate continues, linking science, policy and treatment. This four-part series, with a full complement of data interactives, tests and resources, examines these pressing issues that revolve around childhood trauma.