Nicotine: A Drug of Choice?

Article excerpt


Having resolved to make 1986 smoke-free, some people will try this month to avoid their usual smoky haunts; others will seek diversions from lighting up the next cigarette. Motivation for many will be the scientific data linking tobacco smoking to heart and lung disease and to cancer. According to George Bigelow, associate professor of behavioral biology at Johns Hopkins School of Medicine in Baltimore, there are 350,000 smoking-related deaths in the United States each year--making the daily toll equivalent to that of four air plane crashes of the size of the one that took place Dec. 12 at Gander, Newfoundland.

"Because [smoking] is socially acceptable, we've become inured to the true magnitude of this health problem,' Bigelow told an American Psychological Association science forum last month in Washington, D.C. "Beyondthe loss of life and human misery is the cost in terms of dollars . . . an estimated $39 billion to $96 billion annually [including loss of productivity and $25 billion in medical costs].' Why, with growing evidence of the dangers and high costs of smoking, are more than 50 million Americans smoking cigarettes?

Tobacco industry representatives cite personal choice as the primary reason people continue to smoke. Yet, for the multitude of U.S. tobacco smokers who will try to kick their habit this year (16 million tried in 1980, the most recent estimate), quitting may involve more than the psychological battles of mind over matter, or fears for health over the pleasures of smoking. As reported in the U.S. Surgeon General's latest study on tobacco and health, released last month, a 1980 study found that 60 percent of U.S. smokers had seriously tried to stop smoking. But more than 80 percent who try relapse within the year (see graph)-- many the victims of what recent scientific evidence suggests is actual physical dependency.

Scientists and smokers have long suspected that nicotine, not just the act of smoking, is somehow addictive. But it wasn't until the late 1970s that rigorous experimentation on the addiction theory began, raising questions of how any acceptance of nicotine as a habit-forming drug would affect legislation and litigation. Subsequent research compared the patterns and effects of habitual nicotine use wath addiction to drugs like heroin and amphetamines. Results from some of that research were reported last month at a symposium on the neurobiologic aspects of tobacco smoking held at the University of Kentucky in Lexington.

"The role of nicotine in impulsive tobacco use is the same as the role . . . of cocaine in compulsive coca leaf use,' Jack Henningfield of the Baltimorebased Addiction Research Center of the National Institute of Drug Abuse (NIDA) told SCIENCE NEWS. "We can substitute intravenous nicotine for tobacco in cigarettes and [get the same reaction] from humans and animals. The drug [nicotine] itself is critical.' Nicotine, he says, meets the technical criteria of an addictive drug in laboratory studies by affecting brain wave function, altering mood and serving as a biological reward that elicits certain behavior from both laboratory animals and human volunteers.

Nicotine also appears to have certain beneficial side effects, which could partially explain the urgent craving for a smoke. Unpublished data presented at the Lexington symposium by Henningfield and other researchers agree with some of the thereapeutic effects espoused by smokers.

Testing concentration, short-term memory and other cognitive skills, Henningfield's group found that 20 smokers who quit for 10 days showed significantly slower and poorer test performance within eight hours after the last cigarette. Smoking or nicotine gum restored cognitive skills, the improvement and decline of which corresponded to recorded changes in electrical activity of the brain. "The effect is real, it's physical,' Henningfield says. …