We may never know the true death toll of 9/11, nor the full extent of the psychological trauma the terrorist attacks caused. But by looking at rates of alcohol and other drug use among those who were directly and indirectly affected by the World Trade Center attacks, researchers are discovering insights into our complex psychological response to terror — and into the origins of drug addiction in general.
In a study of 988 Manhattan residents, conducted in the weeks following 9/11, researchers found that 29% reported an increase in substance use. About a quarter of people began drinking more; 1 in 10 smoked more cigarettes; and just over 3% said they smoked more marijuana.
In a 2004 study of 1,570 city residents surveyed six to nine months after 9/11, researchers found that 10% reported an increase in smoking, 18% an increase in alcohol use, and nearly 3% an increase in marijuana use, compared to the month before the terrorist attacks. The researchers also found that symptoms of depression and post-traumatic stress disorder (PTSD) were more common in those who increased their use of alcohol and other drugs, suggesting that those behaviors may have been in part an attempt to self-medicate. Six months later, however, while depression and PTSD among Manhattan residents living below 110th street declined, drug use rates remained elevated.
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But do these trends mean that 9/11 caused increases in addiction? That’s not clear. Reseachers don’t know whether the people who started using more substances post-9/11 went on to become alcoholics or addicts, or whether they may have had earlier drug problems and relapsed. Among the smokers, however, the scientists found that the increase in smoking was seen primarily in pre-existing smokers, although there were some ex-smokers who relapsed and others who started smoking for the first time right after Sept. 11, 2001.
“I think the picture with substance use overall is very complicated,” says Sandro Galea, an author of the 2004 study, published in The American Journal of Drug and Alcohol Abuse, and chair of epidemiology at Columbia University. “Some studies say there was more use, some say less. I think this is a function of the fact that there are several trajectories.”
In other words, people’s reactions to trauma vary widely. Many people may respond by drinking, overeating, taking drugs or seeking other pleasures to soothe anxiety, but just as often, others seem to find meaning in staying clear-headed and taking actions to respond meaningfully to the situation. That may even mean kicking an addiction, rather than starting one, since substance misuse can be driven by a sense of meaninglessness, uselessness and hopelessness.
“We did find some patterns in our work,” says Galea. “My reading is that for every adult for whom a new addiction was created, there is someone who found meaning after 9/11 and stopped using.”
Indeed, the most senseless disasters can become a source of inspiration for some, leading to what has become known as “post-traumatic growth,” which spurs people to help others, work to prevent a repeat of the event or otherwise find a calling in the midst of the aftermath.
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Children are at greatest risk for the most adverse outcomes following trauma — including later substance misuse — because their still-developing brains may be affected. In a 2008 study published in the journal Disasters, researchers looked at 1,040 students who were attending the five middle schools and five high schools closest to the Twin Towers when the planes hit. The researchers surveyed the students 18 months after the attacks.
Those who had just one indicator of significant exposure to trauma — factors like knowing someone who was killed, or being in fear for one’s own life or the lives of loved ones during the attacks — were five times more likely to report increased use of alcohol or other drugs, than kids who had no indicators of trauma. Kids who had three or more trauma-exposure factors were 19 times more likely to misuse substances than nonexposed kids.
Students who reported substance use were more likely to have lower grades, problems with schoolwork and to misbehave at school, suggesting that their use was heavy and frequent.
Other research has also overwhelmingly found a dose-response association between traumatic childhood experience and addiction. For example, the long-term Adverse Childhood Experiences study, conducted jointly by researchers from the Centers for Disease Control and Prevention and Kaiser Permanente found that the more trauma people experienced in childhood, the more likely they were to develop addiction later on.
The researchers examined the medical histories of some 17,000 people insured by Kaiser Permanente in California and interviewed them about their childhood histories. The authors were looking for evidence of 10 categories of potentially traumatic “adverse childhood experiences” (ACEs), including physical abuse, emotional abuse, sexual abuse or loss of a parent to death or divorce.
Then, by comparing people with no ACEs with those who had one or more ACEs, the researchers found a profound dose-dependent effect of trauma on addiction risk: a boy with four ACEs, for instance, is five times more likely to become an alcoholic than someone who has none; he is also 46 times more likely to become an intravenous drug user than a person with no ACEs.
“The general concept of addiction is that it is caused by properties intrinsic in certain chemicals. For example, you take heroin enough times and then you can’t stop using. What we found is the opposite,” says study leader Dr. Vincent Felitti, former chief of preventive medicine at Kaiser Permanente in San Diego. “The underlying dynamics of addiction are related to underlying life experience.”
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Fortunately, most people are resilient to trauma. Two to three years after 9/11, data show that only 12% of recovery workers who worked on “the pile” after the attacks still had symptoms of PTSD. There are many protective factors that keep people from suffering from trauma long-term, but one such factor — which can be sought and provided by anyone — may also help those whose mental-health problems persist: social support.
“Social support is probably the single most clear driver that mitigates the consequences of trauma,” says Galea. “It’s central.”
Indeed, lack of social support is linked with addiction and poor mental health. “Social support is a huge factor,” says Felitti.
It has been undoubtedly difficult this week, with the 10th anniversary of 9/11 approaching, to avoid the media coverage and the reminders of the attacks. But to help put the trauma of the event behind you — and to help keep yourself and your loved ones resilient — one of the best things to do is be a good friend, parent, spouse, child or neighbor, and reach out to those whose social networks may be frayed.
Maia Szalavitz is a health writer at TIME.com. Find her on Twitter at @maiasz. You can also continue the discussion on TIME Healthland’s Facebook page and on Twitter at @TIMEHealthland.