DSM-III criteria for dependence (Hughes et al., 1987). Kandel and associates (1997) used the indicators listed in the NHSDA (see above) including items assessing for frequency and quantity of use and problems related to use in order to diagnose nicotine dependence. The criteria for diagnosis were based on the DSM-IV method in which smokers must experience three or more of seven indicators of dependence. The findings showed that while 8.6% of the general population 12 years and older met criteria for nicotine dependence, 28% of those who had used tobacco products in the past year experienced nicotine dependence. A few studies have also been conducted with adolescents. The study conducted by Kandel and associates (1997) using the NHSDA examined the prevalence of nicotine dependence by age. They observed that about 19.9% of adolescents who smoked any cigarette met criteria for nicotine dependence, compared to rates ranging from 26.4 to 32.7% among smokers between the ages of 18 and 49 years and 23.7% among those 50 and older. In a study conducted in New Zealand, about 20% of a general sample of 18-year-olds were dependent on tobacco and more than half (56.4%) of the sample who smoked daily met DSM-IIIR criteria for nicotine dependence.
In another survey that used the FTQ with a score of 7 or more (indicative of a high level of dependence, not dependence per se), only 19% of Japanese male ever-smokers age 35 and older met this criteria (Kawakami et al., 1998), but 36% of U.S. males did (Hughes et al., 1987). Among adolescent smokers, the prevalence of high level of dependence according to the FTND or FTQ has also been wide-ranging. Many of the studies assessed prevalence of high level of dependence in special populations of adolescents. The highest percentage of adolescents with a score of 7 or more on the FTQ was observed among a heavy-smoking group who participated in a nicotine patch trial, with an observed rate of 68% (Smith et al., 1996). The lowest rate was 20% using a modified FTQ with a cutoff score of 7 or higher, which was observed in vocational technical high school student smokers (Prokhorov et al., 1996). This proportion was lower than the 50% rate that the investigators observed among adult smokers.
An indicator of the addiction potential of a drug is the development of daily or regular use or dependence among those who have been exposed to it. There is strong evidence to show that a significant number who are exposed to cigarettes may become daily smokers or dependent on them. Among high school students participating in the 1997 Youth Risk Behavior Survey (YRBS), of the 70.2% who tried cigarette smoking, 35.8% went on to smoke daily. This rate of escalation from trying cigarette smoking to regular use of tobacco is similar to the 33–50% observed in other studies (U.S. DHHS, 1994). The development of dependence among those who tried tobacco products is similarly high. In one population-