Mentally Ill Twice as Likely to Be Smokers, Study Finds

Nearly half of all cigarettes purchased in the United States are smoked by people who suffer from mental illnesses, according to Harvard Medical School research.

Mentally ill people are roughly twice as likely to smoke cigarettes as those without mental illnesses, according to the research, published in today’s Journal of the American Medical Assn. Not only does the habit put them at greater risk for serious ailments such as heart disease and lung cancer, but in some cases it can interfere with the effectiveness of medications to treat their disorders.

Smoking is often used as a form of self-medication because nicotine can have a powerful impact on mood, according to previous research. And because people with mental illnesses tend to be more cut off from mainstream society and less able to motivate themselves to quit, it may take specially targeted educational efforts to reduce the smoking rates in this group, experts say.

“What works on ordinary, mentally healthy adults may not work as well when we’re dealing with adults with mental problems,” said John Banzhaf, executive director of Action on Smoking and Health, a Washington-based nonprofit advocacy group and a professor of public interest law at George Washington University.

The numbers, though striking, are less surprising when it is considered that drug and alcohol dependencies were among the mental illnesses studied--smoking rates are high in such groups. In addition, in any given year, one in five U.S. adults is estimated to suffer from some form of mental illness. One in 20 suffers from a severe mental illness.

The study, conducted by researchers at Cambridge Hospital and Harvard Medical School, used information from a nationally representative database, consisting of interviews with 4,411 people 15 to 54 years old. This database, known as the National Comorbidity Survey, was compiled in the early 1990s but is still applicable because patterns of smoking and rates of mental illness have not changed much.

Survey participants answered questions about their past and present smoking habits--including whether they had quit--as well as past or current diagnoses of mental illness. Mental illnesses included a wide array of disorders such as major depression, bipolar disorder, anxiety disorders and schizophrenia as well as alcohol and drug dependence.

The researchers found that a person who had suffered from a mental illness during the month before the interview or at some time in the past was more likely to smoke or have smoked in the past. In fact, those who reported a mental illness during the prior month were nearly three times as likely to be current smokers as those who didn’t have a mental illness.

From the survey, the scientists estimated that 44.3% of the cigarettes smoked in the United States are smoked by the mentally ill.

In considering the high smoking rates that are common among people who use other drugs and alcohol, Dr. Ernest Noble, professor of psychiatry at UCLA, said there appears to be a genetic tendency in some addicts that makes them more likely to abuse an array of different drugs.

The link between other mental illnesses and cigarette smoking is also well-known, Noble said. Patients smoke to enhance mood: thus, not illogically, antidepressants have been found to help people quit smoking. And in the case of schizophrenia, the medications that patients must take alter chemicals in their brains, causing a despondency that smoking alleviates. Often, during treatment, “if you don’t allow them to go out and smoke, they become very unruly in a hospital setting,” Noble said.

Some studies suggest, however, that certain mental illnesses may be triggered or exacerbated by smoking, again perhaps because of its mood-altering potential. For instance, in an article in the Journal of the American Medical Assn. published earlier this month, scientists reported that adolescents and young people who smoked heavily were more likely to develop anxiety disorders later in life.

People who suffer from mental illnesses are also more likely to be poor--and smoking is strongly linked to poverty, Banzhaf said. And quitting cigarettes requires long-term planning, impulse control and the ability to personalize risk--all that much harder to do when one’s thinking is impaired by mental illness.

However, the authors found that a sizable number of people with a history of psychiatric disorders had been able to quit smoking, though at a lower rate than those who weren’t mentally ill.

“This was surprising to us--we thought perhaps the quit rate would be lower,” said Dr. Karen Lasser, lead author of the study and a primary care physician at Cambridge Hospital and research fellow at Harvard Medical School. “It’s actually quite hopeful.”

The authors of the latest paper also suggest that the tobacco industry may have been aware of the psychological vulnerability of part of their market. The scientists quote a 1981 document by R.J. Reynolds Tobacco Co., which noted that some smokers smoked for “mood enhancement” and “positive stimulation” or because smoking “helps perk you up,” “calm down,” and “cope with stress.” R.J. Reynolds Co. did not return several calls seeking comment.

But the authors also noted that “no studies have examined the effect of cigarette advertising on the mentally ill.”