Abstract

Social exposure to smoking, or observing smokers, is a robust predictor of adolescent smoking. Recently, an emerging line of research posited that nicotine exposure from secondhand smoke could predict nicotine dependence symptoms and smoking initiation among never-smokers, given that nicotine is a psychoactive substance present in secondhand smoke. The objective of the present research program was to evaluate social exposure to smoking and pharmacological exposure to nicotine from SHS as differential predictors of smoking precursors, such as smoking expectancies, smoking susceptibility, or nicotine dependence symptoms. Adolescent never-smokers constitute an ideal population to study, provided that nicotine exposure from SHS is not confounded by active smoking in that population. This dissertation includes three original quantitative studies.

Using longitudinal data from the NDIT study, Study 1 identified exposure to peer smoking as a significant predictor of nicotine dependence symptoms among never-smokers, which provided convincing evidence that adolescents do not mistakenly endorse such symptoms. Using cross-sectional data from the AdoQuest Study, Study 2 developed the Social Smoking Situations (S3) Scale, an enhanced psychometric instrument measuring the situational contexts in which social exposure to smoking occurs. Compared with existing measures of social exposure (e.g., “who is smoking”), the S3 Scale was a stronger predictor of smoking behavior and smoking expectancies. Finally, Study 3 investigated the differential relations of social and pharmacological exposure to smoking with smoking precursors, using cross-sectional data from the AdoQuest study. This study is the first to demonstrate significant effects of pharmacological exposure to nicotine on smoking expectancies and nicotine dependence symptoms in a sample of adolescent never-smokers.

Overall, this research program provided scientific evidence that exposure to nicotine is a risk factor for smoking among adolescent never-smokers. Its distinctive feature pertains to its emphasis on dismantling the major components of smoke exposure (social vs. pharmacological), and examining their relative consequences on increasing risk for adolescent smoking. It is recommended that future studies use longitudinal data to investigate the unique effects of social and pharmacological exposure on smoking initiation. Finally, current findings could be used to promote complete smoking bans in adolescents’ homes and cars.