[A version of DSM-IV criteria adapted for adolescents and applied to young smokers]

To evaluate nicotine dependence in adolescent smokers using a version of DSM-IV criteria for nicotine dependence adapted for adolescents (DSM-IVa). To establish its usefulness and the most relevant items for diagnosing adolescent smokers.

Two thousand six hundred forty-seven schoolchildren between 10 and 17 years old were surveyed. A sample size was calculated for each year of age, using the finite population equation with the addition of 10% so that the absolute error would not increase at the end of the study if questionnaires were withdrawn. The sample was stratified by sex and type of school for each age group, with allocation to each stratum proportional to the number of individuals. Schools and students were selected using random number tables. The questionnaire collected the most significant personal data and information related to DSM-IVa criteria.

Smokers made up 23.1% of the sample, and 63.5% of them smoked daily. According to the DSM-IVa criteria, 70.7% of the smokers were nicotine dependent. The DSM-IVa had a kappa value of 1 and internal consistency was good (Cronbach's alpha: 0.5598).

The DSM-IVa is useful in the studied population, although not perfect. According to the criteria, 70.7% of those interviewed were already nicotine dependent. The key questions were those that referred to the presence of nicotine withdrawal syndrome symptoms and the need to spend a large amount of free time obtaining or smoking cigarettes.