Children were profoundly affected by the terrorist attacks. A study conducted by the New York Board of Education reported that six months after Sept. 11, 2001 terrorist attacks nine out of 10 New York City schoolchildren suffered at least one symptom of post-traumatic stress.

In the 1.1 million-student public school system, an estimated 75,000 children showed six or more symptoms of post-traumatic stress — enough to be diagnosed with the disorder. Mental health researchers were particularly surprised to find that children throughout the city — not just near ground zero — showed symptoms of several psychiatric problems.

15% of the children surveyed showed symptoms of agoraphobia — the fear of venturing outside the home. In comparison, a 1996 study of several cities showed about 5% of children on average suffered from agoraphobia. The New York City study reported that 12% of school children were experiencing separation anxiety. Almost 10% of the children likely had the full sequela of post-traumatic stress disorder.

These statistics show a 3-fold increase over previous prevalence.

Experts say that all across the US, young people were affected by the events of September 11, even children who may not show signs of problems. Many of these children suffer silently, not talking to anyone or seeking helping about their stress and anxiety.