| MadSci Network: Medicine |
Q: Why no addiction after 25 years of cigarettes? A: You are a chipper. Your astute observation - that there are people that go months between cigarettes, and do not ever seem to develop the characteristic symptoms of dependence or withdrawal - has only really been studied in the past decade. Saul Shiffman, Ph.D., a psychologist at the University of Pittsburgh, was the scientist that first described chippers. Initially these persons were described as those who regularly smoke, but do not develop dependence. In one of the first studies on chippers, the group of smokers studied averaged 5 cigarettes a day, but smoked less than 4 days per week - this is a LOT more than your report of going months between cigarettes. There have been many hypotheses put forth to try to explain the behavior of chippers, including: differences in nicotine metabolism, smoking topography (how you take your puffs), psychological effects (mood, craving), feelings of stress, coping skills, and personality differences (to name but a few). Of all these, the only significant differences between regular smokers and chippers has been in the realm of personality. In one study, Kassel and colleagues (see reference below) found that the trait of sensation-seeking seemed to delineate groups of smokers better than any other criteria. Specifically, nonsmokers were characterized as more socially inhibited compared to chippers and regular smokers (a pack/day). This makes perfect sense given the very social nature of smoking. The other distinction they found was between regular smokers vs chippers and nonsmokers. Regular smokers were more impulsive and demonstrated less self-control than the other two groups. This also makes sense given that smokers would probably be described as addicted to, or dependent on, cigarettes. One of the easiest tests for nicotine dependence is asking a smoker which cigarette of the day would be most difficult to give up (see Jarvik et al, below). Heavy smokers frequently report that the first cigarette of the day when they wake up would be the most difficult (because they are beginning to experience nicotine withdrawal). Chippers and other light smokers report that the cigarette after dinner would be the most difficult (this is perhaps the most reinforcing for them). So how many people are out there like you? That is a very good question. Some government estimates from the National Institute on Drug Abuse (NIDA) estimate that upwards of 90% of smokers are dependent (ie, relatively few chippers). However, there is some evidence to suggest that there are more social smokers and chippers than was previously thought. One reason for this equivocal finding is relatively simple. Scientists may have been asking questions that are not precise enough. Up until recently, distinctions were often made between heavy (more than 20 cigs per day) and light (less than 20 cigs per day) smokers. A second distinction was whether a person had smoked more or less than 100 cigarettes in their lifetime, and whether they were currently smoking. Seems like pretty crude distinctions, no?! As you can probably figure out, there are LOTS of people that might be misclassified using those criteria. More recently, the Centers for Disease Control (CDC) started asking those who HAD smoked whether they still smoked regularly, less than once per day, or not at all. The middle category perhaps best describes a chipper. All of a sudden, there appeared to be many more chippers, and fewer hard-core smokers. So all of this is good news in our war on drugs, right? Well, no. It is great that there are fewer heavy smokers than we thought before, however, smoking1s health risks do not fall along a continuum. There is no safe level of smoking. A really good example of this is the recent evidence surround the health risks of second-hand smoke. Once study has reported that the risk for cancer in light smoking (<10 cigs per day) women was the same as the risk for cancer in asbestos workers. Not reassuring. And there are PLENTY of studies showing that the combination of alcohol and tobacco potentiate the health risks of each drug alone (that is, 2 + 2 = 8 !! ). And since few people only smoke, or only drink alcohol, this is a very real health consideration. So, although the jury is still out on all the health risks, it is very clear that we have a lot to learn about people like you. Most importantly because we have started to find evidence that there may be chippers for all drugs - cocaine chippers, heroin chippers, etc - and these individuals are obviously very different than the typical person who abuses illicit drugs. And if we have learned only one thing in the war on drugs, it is that different types of persons often require different types of treatment regimes (medication and/or psychotherapy) in order to kick their habit. I hope this helps illuminate the issue for you. Thanks for the great question! Cheers, Josh Rodefer, Ph.D. Harvard Medical School josh_rodefer@hms.harvard.edu Selected references You can access these and other articles by doing a MEDLINE search Ð PubMed is one site (www.ncbi.nlm.nih.gov/PubMed/medline.html) that I use frequently. *************************** Jarvik, M, Killen, JD, Varady, A, Fortmann, SP (1993). The favorite cigarette of the day. Journal of Behavioral Medicine, vol 16, pp 413-422. Kassel, JD, Shiffman, S, Gnys, M, Paty, J, Zettler-Segal, M (1994). Psychosocial and personality differences in chippers and regular smokers. Addictive Behaviors, vol 19, pp 565-575. Shiffman, S (1989). Tobacco 3chippers2 Ð individual differences in tobacco dependence. Psychopharmacology, vol 97, pp 539-547. Shiffman, S, Fischer, LB, Zettler-Segal, M, Benowitz, NL (1990). Nicotine exposure among nondependent smokers. Archives of General Psychiatry, vol 47, pp 333-336. Shiffman, S, Paty, JA, Gnys, M, Kassel, JD, Elash, C. (1995). Nicotine withdrawal in chippers and regular smokers: subjective and cognitive effects. Health Psychology, vol 14, pp 301-309.
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