Children who had experienced four or more types of trauma were 32.6 times more likely to have been diagnosed with attention or behavior problems than children who had not experienced any trauma. Other scientists across the U.S. have backed up the broad finding that kids are far more likely to have problems focusing if they experience trauma. For example, Dr. Nicole Brown, in a separate body of research, found that childhood trauma tripled the development of ADHD symptoms. A large study by the British Office of National Statistics found that if there's a financial crisis in the family, a child's chances of being diagnosed with attention problems go up 50 percent. If there's a serious illness in the family, it goes up 75 percent. If a parent has to make a court appearance, it goes up nearly 200 percent. This evidence base is small, but it is growing, and it seems to broadly back up what Nadine found in Bayview. She believed she had uncovered a key truth about focus: To pay attention in normal ways, you need to feel safe.

— Stolen Focus by Johann Hari (Page 172)