Substance abuse has increased in New York City in the aftermath of the 11 September attacks, research suggests.

A survey has shown that smoking and alcohol and marijuana use increased among residents of Manhattan during the five to eight weeks after the terrorist attacks on the World Trade Center (WTC).

Rates of psychological distress and increases in substance use were noticeable throughout New York City

Dr David Vlahov

Almost one-third of the nearly 1,000 people interviewed reported an increased use of alcohol, marijuana, or cigarettes.

The largest increase was in alcohol use.

About one in four of the respondents said they were drinking more alcohol in the weeks after 11 September.

One in ten reported an increase in smoking, and 3.2% said they had increased their use of marijuana.

Dr Glen Hanson, of the National Institute on Drug Abuse (NIDA), said: "This research will help us to design more effective substance abuse treatment and prevention strategies for individuals coping with severe stress."

Random calls

The investigators contacted the survey participants by randomly dialling New York City phone numbers.

During the week prior to 11 September, 2001, 22.6% of the participants reported smoking cigarettes, 59.1% drinking alcohol, and 4.4% using marijuana.

After September 11th, 23.4% reported smoking cigarettes, 64.4% drinking alcohol and, 5.7% smoking marijuana.

Among those who smoked, almost 10% reported smoking at least an extra pack of cigarettes a week and among those who drank alcohol, more than 20% reported imbibing at least one extra drink a day.

The researchers, from the New York Academy of Medicine, found that people who reported an increase in substance abuse were more likely to suffer from post-traumatic stress disorder (PTSD) and from depression.

People who reported an increase in cigarette smoking or marijuana use were also more likely to have both PTSD and depression, while those who reported an increase in alcohol use were more likely to have depression only.

General effect

Researcher Dr David Vlahov told BBC News Online: "The findings were more pronounced among those who lived in close proximity to the disaster.

"However, we found that rates of pyschological distress and increases in substance use were noticeable throughout New York City.

"While people may increase substance use as a way to try and cope with the effects and aftermath of the disaster, continued use may signal problems in coping.

"In particular, cigarette use is particularly addictive, and public health officials need to consider programmes to assist people with smoking cessation."

The research is published in the American Journal of Epidemiology.