Chapter 25. Nicotine as an addicting drug
What is it in tobacco that produces the craving? The answer is well known: nicotine.*
* Dr. M. A. Hamilton Russell wrote (1971): "If it were not for the nicotine in tobacco smoke people would be little more inclined to smoke cigarettes than they are to blow bubbles or light sparklers." 1
The first modern scientific evidence for this conclusion appeared in the English medical journal Lancet in 1942. Dr. Lennox Johnston there reported that he had given small injections of nicotine solution to 35 volunteers, including himself. "Smokers almost invariably thought the sensation pleasant," Dr. Johnston declared, "and, given an adequate dose, were disinclined to smoke for a time thereafter.... After a course of 80 injections of nicotine, an injection was preferred to a cigarette." If the nicotine injections were abruptly discontinued, craving arose. Dr. Johnston found that in satisfying this craving, one milligram of injected nicotine was roughly the equivalent of smoking one cigarette. He concluded that "smoking tobacco is essentially a means of administering nicotine, just as smoking opium is a means of administering morphine." 2
Further evidence for the importance of the nicotine in the cigarette came in 1945, in an experiment undertaken by Drs. J. K. Finnegan, P. S. Larson, and H. B. Haag of the Medical College of Virginia. They secured from the United States Department of Agriculture a batch of a newly developed strain of tobacco specifically bred to contain very little nicotine-much less than the low-nicotine brands now on the market. They added nicotine to half of the batch to bring it up to the usual nicotine level. Then they had both halves of the batch made up into cigarettes identical in all respects except for the nicotine content. The question they sought to answer was the obvious one: would smokers accept the low nicotine cigarettes?
Twenty-four regular smokers, aged twenty-two to fifty, all of them inhalers, participated in the experiment. All of them were given all the cigarettes they wanted, in carton lots. The first cartons handed out contained cigarettes with the usual amount of nicotine. Then, without their knowledge, the smokers were abruptly switched to cartons of the low nicotine cigarettes-and after they had smoked four or more cartons of them, they were switched back again without warning.
Six of the 24 smokers did not miss the nicotine. They "experienced no change in physical or mental tranquility during their period on low nicotine cigarettes."3 These six were clearly not addicted to nicotine. One of them, incidentally, was the heaviest smoker of all, consuming three packs a day both before and during the experiment.
Six others experienced "a vague lack in the satisfaction they normally derived from smoking."
Three "definitely missed the nicotine but became adapted to the change in one to two weeks."
Nine participants "definitely missed the nicotine and continued to do so throughout the period (approximately one month). The symptoms experienced by the latter two groups for the most part took the form of varying degrees of heightened irritableness, decreased ability to concentrate on mental tasks, a feeling of inner hunger or emptiness ... in short, virtually the same symptoms experienced by many individuals on stopping smoking."
Some of the smokers in the last group, Dr. Finnegan and his associates added, "just could not take it." Despite the fact that they had promised to smoke only the cigarettes supplied to them by the pharmacologists, and despite the fact that they could smoke as many of these as they pleased, whenever they pleased, they all admitted to interspersing a few cigarettes of ordinary nicotine content during their period on lownicotine cigarettes." 4
In a Swedish study reported in 1959, Drs. B. Ejrup and P. A. Wikander gave subjects increasing injections of nicotine over a ten-day period. The subjects felt satisfied and saturated; they either took only a few puffs of a cigarette from time to time or gave up smoking entirely on the days when they received injections.5
All of these studies had certain flaws in design. In 1967, however, Drs. B. R. Lucchesi, C. R. Schuster, and G. S. Emley reported a very nearly flawless experiment at the University of Michigan Medical School that produced parallel results.6 Each subject participating in this experiment spent six hours a day for fifteen consecutive days in a soundproof, air conditioned isolation booth with a needle in an arm vein. He could read or smoke or engage in other quiet activities as he chose. On some days, ordinary salt water was fed into the vein through the needle; on other days a nicotine solution was fed in. The nicotine solution was so dilute that a subject could not tell the difference between it and the salt water. More important, the subjects did not know that the experiment had anything to do with smoking or with nicotine. They simply knew that there was an ashtray handy, so they could smoke if they pleased.
On days when salt water was injected, the subjects smoked an average of 10.1 cigarettes per six-hour session. On nicotine-injection days, they smoked only 7.3 cigarettes and they left significantly longer butts.* 7 The injected nicotine had markedly diminished their internal demand for cigarette nicotine.
* The longer butt length as well as the fewer cigarettes smoked meant a significant reduction in nicotine consumption. For the cigarette itself acts as a filter; much of the nicotine in the early puffs of smoke remains in the cigarette and only reaches the smoker in the later puffs.
Dr. C. D. Frith of the Institute of Psychology, London University, England, reported somewhat similar results in 1971.8 The nine male subjects in his sample, all of them accustomed to smoke more than 15 cigarettes a day were given low-nicotine cigarettes on some days, moderate-nicotine cigarettes on other days, and high-nicotine cigarettes on the remaining days. The more nicotine in the cigarettes, the longer the time elapsed between one puff and the next. The more nicotine in the cigarettes, the longer it took to smoke one cigarette. The more nicotine in the cigarettes, the fewer cigarettes were smoked per day. All three of these relationships point to the same conclusion: the smoker smokes to get nicotine, and regulates his smoking to assure the desired nicotine dosage, puff by puff, minute by minute, and day by day.
The same year, Dr. B. L. Levinson and three associates, of Harvard University, reported on an experiment involving efforts to "taper off" cigarette smokers by permitting them to smoke fewer and fewer cigarettes per day over a twelve-week period. "The greatest difficulty in further smoking reduction occurred at the 12-14 cigarettes per day level . . . " the study noted. "It was hypothesized that . . . further reduction is inhibited by the manifestation of withdrawal symptoms caused by some physiological addiction." 9
The view here presented-that cigarette smoking is for most smokers an addiction to the drug nicotine-has a small but growing body of proponents in the United States. Scientists in other parts of the world, too, are increasingly accepting this view. In Britain, indeed, the nicotine addiction view of smoking has now been espoused by the Addiction Research Unit (ARU) of the Institute of Psychiatry, London-a unit initially established to study heroin addiction.
"We can no longer afford to regard cigarette smoking as a 'minor vice, ' " Dr. M. A. Hamilton Russell of the ABU reported in 1971. "It is neither minor nor a vice, but a psychological disorder of a particularly refractory nature and all the evidence places it fair and square in the category of the dependence disorders." By "dependence disorder," Dr. Hamilton Russell means (as shown below) very nearly what this Consumers Union Report means by "addiction." He then continues: "It is the belief that all dependence disorders may be in some way related, and that cigarette dependence is an important member of this group, that has prompted the Addiction Research Unit ... to add cigarette smoking to its field of study." 10 We shall cite a number of additional ARU conclusions in the discussion that follows.
One hallmark of all addicting substance is the fact that users seek it continuously, day after day. If they can take it or leave it-take it on some days and not be bothered by lack of it on other days-they are not in fact addicted. judged by this standard, nicotine is clearly addicting; the number of smokers who fail to smoke every day (except among children just learning to smoke) is very small. The typical pattern of nicotine use, moreover, is not only daily but hourly. Nearly four male smokers out of five and more than three female smokers out of five consume 15 or more cigarettes a day-roughly one or more per waking hour. Here are the figures, from a 1966 United States Public Health Service survey of a cross-section of the adult American population."
|Number of cigarettes per day||Males||Females|
|0 through 4||6.0||10.9|
|5 through 14||15.3||26.9|
|15 through 24||43.9||45.2|
|25 through 34||19.8||9.2|
|35 through 44||11.0||6.3|
|45 through 54||2.1||0.8|
No other substance known to man is used with such remarkable frequency. Even caffeine ranks a poor second.
Dr. Hamilton Russell of the ARU has a physiological explanation for this hourly-or-oftener pattern of use:
Certainly the level of nicotine in the brain is crucial for the highly dependent smoker. The blood-brain barrier is no barrier to nicotine. On the basis of animal studies it is probable that nicotine is present in the brain ... within a minute or two of beginning to smoke, but by 20-30 minutes after completing the cigarette most of this nicotine has left the brain for other organs (e.g., liver, kidneys, stomach). This is just about the period when the dependent smoker needs another cigarette. The smoking pattern of the dependent smoker who inhales a cigarette every 30 minutes of his waking life [a pack and a half a day] is such as to ensure the maintenance of a high level of nicotine in his brain.12
Dr. Hamilton Russell also notes: "It is far easier to become dependent on cigarettes than on alcohol or barbiturates. Most users of alcohol or sleeping tablets are able to limit themselves to intermittent use and to tolerate periods free of the chemical effect. If dependence occurs it is usually in a setting of psychological or social difficulty. Not so with cigarettes; intermittent or occasional use is a rarity-about 2 percent of smokers." 13
In the discussion of heroin in Part 1, it was noted that nobody knows how many casual "weekend users" end up as heroin addicts and how many escape addiction. Dr. Hamilton Russell does provide statistics of this kind with respect to nicotine. "It requires no more than three or four casual cigarettes during adolescence," he reports, "virtually to ensure that a person will eventually become a regular dependent smoker." 14 And again: "If we bear in mind that only 15 percent of adolescents who smoke more than one cigarette avoid becoming regular smokers and that only about 15 percent of smokers stop before the age of 60, it becomes apparent that of those who smoke more than one cigarette during adolescence, some 70 percent continue smoking for the next 40 years." 15
Dr. Hamilton Russell then goes on to explain this remarkable long term effect of a few early smoking experiences: "The first few cigarettes are almost invariably unpleasant." Hence an adolescent may try one cigarette, decide he doesn't like it, and never smoke again. But if, despite the unpleasant side effects, he goes on to smoke a second and then a third and fourth, "tolerance soon develops to the unpleasant side-effects and skill is quickly acquired to limit the intake of smoke to a comfortable level, thus lowering the threshold for further attempts. Herein lies a possible cause of the virtual inevitability of escalation after only a few cigarettes. With curiosity satisfied by the first cigarette, the act is likely to be repeated only if the physical discomfort is outweighed by the psychological or social rewards. If these motives are sufficient to cause smoking to be repeated in the face of unpleasant side-effects, there is little chance that smoking will not continue as these side-effects rapidly disappear." 113 Once the threshold-the third or fourth cigarette-has been crossed, few turn back.
In Part 1, we noted the widespread but mistaken belief that heroin addiction can be cured-by sending addicts to Synanon, or to Daytop, or to prison, or to one of the California, New York State, or federal rehabilitation centers. The unwillingness to recognize tobacco as a truly addicting drug runs even deeper. Many people, for example, do not recognize tobacco as a drug at all. They still see smoking as a "bad habit," to be given up like fingernail-biting or thumb-sucking. In an effort to demonstrate that nicotine is not addicting, three arguments are commonly offered.
First, it is alleged that the withdrawal of nicotine does not produce withdrawal symptoms; hence there is no physical dependence on nicotine. A 1966 study by the American Institutes of Research, made under a grant from the United States Public Health Service, demolishes this allegation. Among smokers deprived of their drug, the study indicates, 59 percent of males and 61 percent of females report drowsiness; 41 percent of males and 47 percent of females report headaches; 27 percent of males and 38 percent of females report digestive disturbances; and so on. in general, females report more symptoms than males. The table below supplies details.
|Symptoms during smoking withdrawal||Males 17||Females 11|
|Constipation or diarrhea||27||38|
Dr. Peter H. Knapp and his associates at the Boston University School of Medicine have directly observed and measured withdrawal signs and symptoms under double-blind conditions-and have shown that it is nicotine rather than some other smoke ingredient which is responsible for at least some of them.19
Dr. Hamilton Russell of the ARU adds that the craving for nicotine, too, may in fact be a physiological withdrawal symptom. "Psychological processes are mediated by physiological events. Intense subjective craving, so long regarded by the unsympathetic as 'merely psychological,' may well be governed by physiological adaptive mechanisms in the hypothalamic reward system which are no less 'physical' than the similar mechanisms . . . responsible for many of the classical phenomena of opiate withdrawal."20 And Dr. Hamilton Russell states: "Most smokers only continue smoking because they cannot easily stop.... If he smokes at all, the most stable well-adjusted person sooner or later becomes a regular dependent user (or misuser)-in other words, he is hooked ." 21 Or, in the terminology of this Report, he is addicted.
A second argument seeking to distinguish cigarette smoking from true addiction alleges that smokers do not become tolerant to nicotine. This argument is equally fallacious. The youthful smoker begins with a few puffs. He is soon able to tolerate most of a cigarette. As his tolerance rises, he may smoke two cigarettes the same day, and then three, leaving shorter and shorter butts. If he exceeds his tolerance, he suffers signs of acute toxicity-pallor, sweating, nausea, perhaps vomiting, and so on. In due course, as tolerance rises further, be may reach ten or even fifteen cigarettes a day-a level that might have proved disastrous earlier in his smoking career. Eventually he levels off at a pack a day or more.
Dr. Hamilton Russell of the ARU adds some fascinating physiological details:
The third effort to distinguish cigarette use from addiction alleges that cigarette use does not lead to antisocial behavior. As shown in Part 1, however, it is not heroin addiction but the limited availability and high cost of black-market heroin which leads to antisocial behavior among heroin addicts. Much the same is true with respect to nicotine addiction. When the supply of cigarettes is curtailed, cigarette smokers behave remarkably like heroin addicts. Following World War 11, for example, the tobacco ration in Germany was cut to two packs per month for men and one pack per month for women. Dr. F. 1. Arntzen of the Research Center for Psychodiagnosis in Munster, Germany, questioned hundreds of Germans during this cigarette famine, and reported his findings in the American Journal of Psychology in 1948.
"Up to a point," Dr. Arntzen noted,
the majority of the habitual smokers preferred to do without food even under extreme conditions of nutrition rather than to forego tobacco. Thus, when food rations in prisoner-of-war camps were down to 900-1000 calories, smokers were still willing to barter their food rations for tobacco. Of 300 German civilians questioned, 256 had obtained tobacco at the black market, 37 had bought tobacco and food, and only 5 had bought food but no tobacco. Many housewives who were smokers bartered fat and sugar for cigarettes. In disregard of considerations of personal dignity, conventional decorum, and esthetic-hygienic feelings, cigarette butts were picked up out of the street dirt by people who, on their own statements, would in any other circumstances have felt disgust at such contact. Smokers also condescended to beg for tobacco, but not for other things....
In reports on subjective impressions, 80 percent of those questioned declared that it felt worse to do without nicotine than without alcohol.* 23
* Reports of women who are willing to prostitute themselves for a carton of cigarettes, and of men who trade stolen goods for cigarettes, are also common during and after Wars.
The German experience after World War II suggests an explanation of why we Americans in recent generations have lost awareness of the addicting nature of nicotine. People become acutely aware of an addiction only when their supply is cut off. The Indians before Columbus knew that tobacco was addicting because their supply was precarious; * and the same was true of the sixteenth-century mariners. In the twentieth century, in contrast, warehouses and channels of' distribution have been organized so that cigarettes are conveniently and continuously available; it is seldom necessary to "walk a mile for a Camel." Only when the supply is cut off-as, for example, when someone decides to give up smoking-does the smoker become acutely aware of the craving. Even then, because of the devastating implications of being addicted to a drug, he tends to deny being addicted-even though the intensity of the craving causes him to violate his resolution and start smoking again.
* The question, indeed, may even be raised whether nicotine addiction was a factor in converting hunting and fishing tribes to agriculture. Perhaps tobacco culture came first, to assure a continuing supply. Tribes thus tied to their tobacco fields and unable to migrate to fresh hunting grounds would next have to cultivate corn, beans, or other nutrient crops in order to maintain themselves in their newly fixed abodes.
The data from "smoking clinics" tend to confirm the view that cigarette smoking is an addiction. These clinics offer groups of men or women who want to stop smoking many kinds of aid and encouragement. In 1970, Professor William A. Hunt, psychologist at Loyola University in Chicago, and Professor Joseph D. Matarazzo of the Department of Medical Psychology, University of Oregon School of Medicine, reviewed the relapse rates among attendees at seventeen clinics where "valid and reliable" followup studies had been made. The combined relapse rate of these seventeen studies for smokers who successfully stopped smoking is graphically portrayed in Figure 10. At the end of forty-eight months, more than 80 percent of those who had successfully stopped were smoking again. Even among those abstinent for an entire year, one-third or more relapsed during the next three years. Professors Hunt and Matarazzo comment that the shape of the curve shown in Figure 10 is quite similar to the shape of the curve portraying relapse among heroin addicts.25
Note that the 20 percent success rate at the end of the fourth year does not apply to those who entered the seventeen clinics; it applies only to those who successfully stopped during therapy. Failures in the course of therapy are excluded.