Changes in Attitudes, Intentions, and Behaviors toward Tobacco and Marijuana during U.S. Students' First Year of College

Tobacco and marijuana are commonly used by college students and have negative health effects. The purpose of the study was to understand how students' attitudes, intentions, and behaviors toward tobacco and marijuana change during freshman year and to examine how attitude and intention predict use of these substances. College students completed phone interviews before and after freshman year. The identical interviews assessed students' attitudes, intentions, and behaviors toward both substances. Attitude was measured on a 0-6 scale (6 = most positive), intention on a 0-5 scale (5 = very likely to use), and behavior by lifetime use (yes or no) and current use (past-28-days). Overall, 275 participants completed both interviews. Attitudes increased (tobacco 0.9 to 1.2, p < 0.01; marijuana 1.9 to 2.3, p < 0.01). Intentions increased (tobacco 0.4 to 0.8, p = 0.03; marijuana 0.7 to 1.1, p < 0.01). 12.2% initiated tobacco, 13.5% initiated marijuana. Only intention predicted tobacco initiation, while both attitude and intention predicted marijuana initiation. Attitudes, intentions, and behaviors changed significantly towards favored use. Predictors of use varied by substance, suggesting that different prevention approaches may be beneficial.