Project TNT is a 10-day, classroom-based program implemented in the 7th grade and followed by two booster lessons in the subsequent year (Dent, et al., 1995; Sussman, et al., 1993). This intervention program includes activities to address three major targets: (1) normative social influence (peer pressure), (2) informational social influence (statements by one's peer group, parents, tobacco advertisements, or others that suggest that tobacco use is widespread or confers a positive social image), and (3) inaccurate or incomplete knowledge about the physical consequences of tobacco use. Seventh graders in 48 junior high schools in California were randomized, by school, to receive their standard curriculum or one of four intervention curriculums-one each to target normative social influence, informational social influence, and knowledge of physical consequences, and a combined curriculum designed to target all three components. The target population included both urban and rural populations, and, although the study was restricted to majority white school districts, there was some diversity of ethnic groups, as the 7th graders were 60% white, 27% Hispanic, 7% black, and 6% Asian or other. At one- and two-year follow-ups, participants in the full TNT program showed attenuations in weekly use of both cigarettes and smokeless tobacco relative to the controls, who received their usual health curriculum. For example, between the 7th and 9th grades, the typical increase in the prevalence of weekly cigarette use with age was cut by more than half among TNT participants when compared with the controls. There was a 9 percentage-point increase among the controls, compared with an increase of just 4 percentage points among TNT participants. Notably, the physical consequences curriculum, more extensive than the traditional and ineffective information-based programs, was particularly successful in reducing use of smokeless tobacco.

In teaching resistance skills and general life skills, the Life Skills Training (LST) program aims to equip adolescents with the information and skills they need to resist social influences to smoke and to enhance personal characteristics associated with a decreased risk of smoking (Botvin, Baker, Dusenbury, Botvin, & Diaz, 1995; Botvin, et al., 1989; Botvin, et al., 1992). The longest-term follow-up evaluation of the LST curriculum was conducted among 56 schools in a primarily white, high socioeconomic status area in New York state (Botvin, et al., 1995). Schools were randomized to LST or usual curriculum conditions. The LST intervention included 15 class periods in the 7th grade, 10 in the 8th grade, and 5 in the 9th grade. Class sessions were designed to enhance student's cognitive-behavioral skills for: self-esteem building, resistance to media influences, anxiety management, effective communication, development of personal relationships, and resistance to peer and other pressures to use tobacco. Program activities included demonstration of skills, behavioral rehearsal, feedback, and reinforcement, and assignments to practice skills outside of class. Students were followed for an average of 6 years. At follow-up, the prevalence of monthly, weekly, and heavy (one or more packs per day) smoking was lower in the LST condition than in the control group, particularly among those students in classrooms in which a more complete implementation (at least 60%) of the program was delivered. Among LST subjects who had been exposed to at least 60% of the program, the prevalences of monthly and weekly cigarette smoking and the prevalence of heavy smoking were at least 25% lower than in the no-intervention control group. For example, 27% of controls reported weekly smoking at follow-up, compared with 20% of students in the high-implementation group, and 12% of controls smoked at least a pack a day, compared with 9% of high-implementation program participants. These findings are particularly noteworthy given that many programs have found a rapid deterioration of impact on smoking behavior as the time since intervention increases (e.g., Bell, Ellickson, & Harrison, 1993). It may be that the extent of intervention, extensive booster sessions, comprehensive nature of the program, and consideration of implementation fidelity bolstered the success of the LST program over the long term (Botvin, et al., 1995). In shorter follow-up studies, the LST program has shown marked success in a diversity of settings, including urban schools that are primarily Hispanic (Botvin, et al., 1992) or black (Botvin, et al., 1989). LST has also had success in the prevention of use of alcohol and other drugs (Botvin, et al., 1995).

It is important to note a few caveats to the LST findings. First, the subset of program participants who were exposed to at least 60% of the program may not be comparable to the whole set of students who were initially randomized to the program and control conditions. This would eliminate the analytical benefits of the original randomization of participants to the study conditions. Second, as may be true for other researchers in the field, Botvin and colleagues do have a potential conflict of interest since they are profiting from the sales of their program protocol (Cohn, 2001).