© ColorBlind Images\Blend Images\Getty Images(© ColorBlind Images\Blend Images\Getty Images )

When Dawn adopted her 7-year-old nephew, Dylan (not their real names), she expected a difficult initial adjustment. The 51-year-old Wisconsin homemaker, who is married to an attorney, has 10 children—8 adopted, 2 biological—and jokes that her occupation is "laundry." She knew that Dylan had been starved and neglected by his cocaine-addicted mother.

But what Dawn didn’t expect was for her nephew to be diagnosed with attention-deficit/hyperactivity disorder. "He was climbing the walls," she says. "He couldn't even sit still to eat." At school, he wasn't learning because he was in constant motion.

Dawn suspected that Dylan's main problem wasn't really ADHD. Her pediatrician wanted him evaluated and suggested medication. "It was tempting," she says, but "I had a gut feeling I should wait." Dawn believed that her nephew's inattention and over-activity were linked instead to his disrupted parental relationships and chaotic early experience.

Identifying trauma

Dawn's maternal intuition about the effects of trauma on attention is increasingly backed by science. "The big problem is that people just don't identify trauma in kids," says Claude Chemtob, professor of psychiatry and pediatrics at Mt. Sinai Medical School in New York City, who recently published a study of children who were attending preschools near the World Trade Center on Sept. 11, 2001.

Though we tend to think of traumatic experiences as rare, in fact, by age 16, seven of 10 children have been exposed to at least one potentially traumatic event—such as a natural disaster, severe car accident, child abuse or the loss of close family member—according to a study of a representative sample of more than 1,400 children living in North Carolina published in 2007.

In Chemtob's 9/11 study, even children who saw people jump from the towers tended not to have lasting problems. But preschoolers who had experienced multiple traumatic events were 16 times more likely to have attention problems—and 21 times more likely to be overly emotionally reactive and/or to show symptoms of depression and anxiety—than children who had not had such experiences.

But, if other studies of similar children are a guide, many of these severely affected children would probably not meet criteria for post-traumatic stress disorder. Studies following children with known trauma exposure find that they are much more likely to suffer other anxiety disorders or depression than classic PTSD.

Indeed, despite the high prevalence of potentially traumatizing experiences, less than half a percent of the children followed in the North Carolina study could be diagnosed with PTSD. However, 40 percent of those who had had such experiences qualified for at least one diagnosis, often depression or anxiety disorders.

As a result, many traumatized children whose behavior has clearly been affected by their experiences aren’t diagnosed with PTSD—or diagnosed at all. Chemtob notes that "virtually none" of the children in his study were getting any kind of treatment, despite symptoms severe enough to warrant it.

Other children are vulnerable to being labeled with an alphabet soup of diagnoses, including ADHD, because trauma profoundly affects many different parts of the brain and can produce widely varying behaviors and outcomes.