When smoking becomes a disorder

Smoking is the leading cause of preventable death in the United States. Yet despite overwhelming evidence that smoking can kill, more than 2 of 10 Americans continue to light up. A new study may provide insights as to why.

Almost 70% of smokers suffer from some type of psychiatric or mental disorder, including nicotine dependence, the study found. That dependence is considered more severe than a simple habit and is defined as a chronic addiction to nicotine, comparable to other substance abuse disorders.

Such disorders make quitting smoking even more difficult than would ordinarily be expected.

Researchers at the National Institute of Alcohol Abuse and Alcoholism in Bethesda, Md., analyzed the 2001-02 National Epidemiologic Survey on Alcohol and Related Conditions and subsequent interviews with 43,093 people with psychiatric disorders.

The study revealed that nicotine-dependent people make up only 12.8% of the overall population but consume 57.5% of all cigarettes smoked in the United States. Similarly, nicotine-dependent people who also have psychiatric disorders comprise 7.1% of the population yet smoke 34.2% of all cigarettes.

“These are huge numbers,” said Bridget F. Grant, the lead author of the study and an epidemiologist at the institute.

Grant defined nicotine dependence as a mental disorder in which compulsive use is often chronic and continues even though people have serious medical conditions that are caused or exacerbated by smoking. “These are people who’ve tried to quit a million times and can’t, and also have severe withdrawal symptoms -- nausea, vomiting, anxiety -- when they try to stop,” she said.

If smoking cessation programs are to be successful, Grant said, they also must target the underlying mental disorders, such as nicotine dependence. “These people need more than just a patch to quit,” she added.

The study appeared in the November issue of the Archives of General Psychiatry.