Nearly half of American children go through at least one adverse childhood experience (ACE) — a potentially traumatic event that can have lasting negative effects on their health and well-being — a research brief from Child Trends finds. Based on data from the National Survey of Children's Health, the brief, Adverse Childhood Experiences: National- and State-Level Prevalence (11 pages, PDF), found that 35 percent of children nationwide reportedly had one or two such experiences, while 11 percent had three or more. Economic hardship (26 percent) is the most commonly reported ACE, followed by parents' divorce or separation (20 percent), living with someone who abuses alcohol or drugs (11 percent), being a victim of or witnessing neighborhood violence (9 percent), and living with someone with a mental illness (9 percent). The brief also found that, with the exception of economic hardship, which was reported about equally across all age groups, the prevalence of ACEs increases with a child's age. The report includes state-by-state data on the prevalence of the five most common ACEs, as well as state rankings in the highest and lowest quartile for each of eight ACEs.