The natural history of college smoking: trajectories of daily smoking during the freshman year.

Although the initiation of cigarette use typically occurs prior to age 18, there is evidence for considerable change in smoking behavior after this age. College may be a particularly important period to study smoking because it is a time when adolescents transition into a new social context where substance use is normative. Using a longitudinal design, daily assessments of smoking were collected during the entire first year of college for a large cohort of freshman (N=496). Findings suggested a weekly cycle of smoking such that the probability of smoking was much higher on weekends (Friday and Saturday) than on remaining days of the week. In addition to this weekly cycle, there was an overall trend for smoking to decline over the course of the year. Substantial individual variability in levels of smoking was observed. These findings provide new insights into college smoking, and have implications for assessment, policy, intervention, and future directions for research.