Researchers from Weill Cornell Medical College's Department of Public Health claim the terrorist attacks carried out on September 11, 2001 resulted in one million former smokers around the United States picking up their cigarette habits again.

This one-of-a-kind study aimed to track statistics for terrorism-induced smoking using the 9/11 terrorist attacks, with the 1995 Oklahoma City bombing as a basis for comparison. The research team hopes their findings can lead to a suitable form of stress therapy after a traumatic event in the future.

"This study provides the first unbiased estimate of the effect of stress on smoking, and the finding that there was such a big increase in smoking nationwide, seemingly due to one event, is extraordinary, and surprising. It sheds light on a hidden cost of terrorism," said the study's lead investigator Dr. Michael F. Pesko.

"There is a consensus in the research community that stress is a very large motivator for individuals to use substances, but this has not really been studied very thoroughly."

For the basis of their study, Pesko and his colleagues used a survey tracking annual rates of risky personal behavior across the United States known as the Behavioral Risk Factor Surveillance System. The research team pulled 1,657,985 responses that involved self-reported days of stress and starting to smoke again as a response.

After narrowing data to between 2001 and 2003, their findings determined that 950,000 to 1.3 million, or 2.3 percent, former smokers picked up the habit after the events on 9/11. However, there was no distinguishable increase in smoking statistics following the Oklahoma City bombing in 1995.

"I was really surprised to find that former smokers across the nation resumed their old habit. I was expecting to see impacts just in the New York City area -- or, at most, the tri-state area," Pesko added.

"This helps us better understand what the real costs of such disasters are in human and economic tolls, and it suggests ways that such future stressful reactions that result in excess smoking might be avoided."

Although people often report feeling less stressed after a cigarette due to nicotine's psychoactive properties, smoking actually increases physical measures of stress. According to the Cleveland Clinic, while a person the their body experiences elevated blood pressure levels, increased heart rate, tensing of muscles, decreased oxygen to the brain, and a constriction of blood vessels from the stimulant effects of nicotine, which are addictive.

To find healthier alternatives for dealing with stress, visit the Centers for Disease Control and Prevention's Tips for Managing Stress.

Source: Pesko M. Stress from 9/11 Linked to Nationwide Resurgence in Smoking Among Americans Who Had Quit. Contemporary Economic Policy. 2013.