"The most common things we saw were anxiety disorders, PTSD and depression," Muller said.
According to the report, the PTSD rate was highest among people who were injured during the attacks (35 percent), low-income people (31 percent) and Hispanics (30 percent). Overall, minorities, low-income individuals and women experienced higher rates of both mental and physical problems.
"There are a couple of factors that seem to predispose people to having persistent symptoms," Landrigan said. "One is having directly witnessed the trauma like people jumping out of buildings, which seems to have been worst of all. Second is having preexisting mental health problems, people who are already anxious."
Children who had experienced previous trauma were also at heightened risk as were people who did not have specific training, the so-called "naive volunteers."
"These would be people like construction workers, thousands of constructions workers who jumped into bulldozers and rushed to the site on the afternoon of 9/11 to help with rescue and recovery," Landrigan said. "It made a huge difference, but they're not used to dealing with death and destruction, and most have been devastated."
Preschool children exposed to "high-intensity WTC attack-related events" are at increased risk for sleep problems and anxious/depressed behavioral symptoms, reported a study in the Feb. 2008 issue of the Archives of Pediatric & Adolescent Medicine.
The 9/11 attacks also altered, literally, the dreams of Americans, with dreams after the disaster showing more intense images.
And all of this is in the context of lingering physical health problems. Studies have documented that people with no history of heart problems who felt extremely stressed following the 9/11 terrorist attacks were prone to heart problems in the three years following the attacks.
The recent WTC Health Registry report found that 3 percent of adult residents in lower Manhattan and workers had developed asthma two to three years after the attack.
"Most of the firefighting department [including emergency medical technicians] were present at the World Trade Center the first couple of days," said Dr. Thomas Aldrich, a professor of medicine at Montefiore Medical Center and Albert Einstein College of Medicine in New York City. "A tremendous number of people were exposed and virtually everyone had a cough. Most got better, but a percentage had persistent symptoms. Approximately 800 firefighters and EMTs have retired because of respiratory disabilities, which is unprecedented."
There's more on health issues following the 9/11 attacks at the World Trade Center Health Registry.
SOURCES: Katherine L. Muller, Psy.D., clinical psychologist, director, psychology training, and director, Cognitive Behavior Therapy Program, assistant professor, psychiatry and behavioral sciences, Albert Einstein College of Medicine, Montefiore Medical Center, New York City; Philip J. Landrigan, M.D., professor and chairman, Department of Community & Preventive Medicine, professor, pediatrics, and director, Children's Environmental Health Center, Mount Sinai School of Medicine, New York City; Lorna Thorpe, Ph.D., deputy commissioner, New York City Department of Health & Mental Hygiene; Thomas Aldrich, M.D., professor, medicine, Montefiore Medical Center and Albert Einstein College of Medicine, New York City; Journal of Public Health; February 2008 Archives of Pediatric & Adolescent Medicine