Adverse childhood experiences (ACEs) encompass various forms of physical and emotional abuse, neglect, and household dysfunction experienced in childhood. ACEs have been linked to premature death as well as to various health conditions, including those of mental disorders. Resulting toxic stress has also been linked to childhood maltreatment, which is related to a number of neurological changes in the structure of the brain and its function. The Adverse Childhood Experiences Study was the first large scale study to look at the relationship between ten categories of adversity in childhood and health outcomes in adulthood.