Introduction: Identifying trajectories of cigarette smoking based on usage patterns is important in elucidating the pathway from initiation to nicotine dependence. Various methods have been used to identify different smoking patterns based on either quantity or frequency smoked.
Methods: This paper examines the link between smoking exposure and nicotine dependence symptoms while looking at both daily and less-than-daily smokers in a nationally representative sample.
Results: Our study found a distinct pattern of cigarette smoking among adolescents aged 12-18 years, suggesting a trajectory in which smokers typically progressed through the following steps: smoking less than 1 cigarette on 1-5 days per month; smoking 1-5 cigarettes on 1-5, 6-9, 10-19, 20-29, and 30 days; and then smoking 6-10 cigarettes on 30 days, 11-20 on 30 days, and more than 20 on 30 days. Few smokers deviated from this pattern. A dose-response relationship was observed between this smoking pattern and having any of the four nicotine dependence symptoms and also with the number of reported nicotine dependence symptoms.
Discussion: The relationship we found between smoking exposure and nicotine dependence symptoms is consistent with the homeostasis-sensitization theory: according to which sensitization involves periods in which a person is increasing the number of cigarettes smoked per day and homeostasis occurs when the number of cigarettes smoked per day remains stable. We provide data that can be used in future studies to update and expand the work on trajectories.