By Joene Hendry

NEW YORK (Reuters Health) - There is no one-size-fits-all explanation for why teenagers take up smoking, hint findings of a Canadian study.

Therefore, focusing on one single risk factor is not likely to help adolescents resist peer pressure to smoke, or help advance the understanding of why young people smoke, Dr. Jennifer O'Loughlin and colleagues report in the American Journal of Epidemiology.

O'Loughlin, at the University of Montreal in Quebec, therefore suggests that efforts to prevent smoking should take into account "individual-level factors such as age, self-esteem, alcohol use, and academic success." Those involved should also bear in mind "contextual factors such as smoking in parents and friends, and school smoking policies," she told Reuters Health in email correspondence.

Her group investigated how numerous factors altered smoking initiation among 877 students (half male), who were pushing 13 years of age at the start of the study and had never smoked.

Every 3 months for the next 5 years, the researchers surveyed students' smoking habits and other factors potentially linked with starting to smoke. During this period, 421 (48 percent) of the students started smoking, and 87 (21% of these) took up daily smoking.

Living in a single-parent family and poor academic performance in school all increased smoking risk. Using alcohol and other tobacco products upped risk nearly 3- and 5-fold.

Having siblings and friends who smoked raised an adolescent's risk for smoking about 2- and 3-fold. Having a parent or teachers and school staff who smoked increased the risk of beginning to smoke by about half or more.

Feeling the need for a cigarette raised smoking risk 6-fold. Adolescents who felt stressed, acted impulsively, and showed susceptibility to tobacco advertising were also more likely to begin smoking.

By contrast, gender, parents' education, feelings of depression, worry about weight or being overweight, seeking novel experiences, physical activity or playing sports, and television watching were some of the factors not linked with increased risk.

Prevention and cessation programs that target social, home, and school smoking, as well as tobacco advertising, may have a positive impact on adolescent smoking, O'Loughlin and colleagues surmise. They call for further investigations into factors linking alcohol use and smoking, and genetic variables tied to smoking risk.

SOURCE: American Journal of Epidemiology, September 1, 2009.

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