| Cigarette smoking is considered the number one preventable cause of premature death in the United States. Despite adverse health consequences, about half of US youths have tried cigarettes by twelfth grade. Thus it is necessary to study the factors associated with smoking initiation among adolescents to improve efforts to prevent onset of smoking.; Depression is associated with nicotine involvement, but few studies have focused on the time-specific relationship between depression and subsequent smoking initiation. Few studies have been conducted among urban adolescents mainly from low-income families or have examined subgroup variation. The overarching purpose of this study was to fill this gap and examine the temporal relationship between depressive symptoms and smoking initiation, and possible variation by gender and intervention status, in a sample of urban adolescents attending public schools in a mid-Atlantic metropolitan area. Associations between initiation of smoking and socioeconomic, familial, and environmental factors were also examined.; This study drew upon data from the second generation of an ongoing prospective randomized intervention trial by the Johns Hopkins University Prevention and Intervention Research Center (JHU-PIRC). A total of 678 urban first-graders from 27 classrooms across nine elementary schools were randomly assigned to one of the three intervention arms: classroom-centered curriculum intervention (CC), family-school partnership intervention (FSP), or control condition without any special intervention. These students were followed up to twelfth grade. The analytic sample was restricted to the 554 students who had complete information on age at smoking initiation and had never smoked by grade 6. Discrete-Time Survival Analysis (DTSA) in a latent variable framework was used to examine the timing of smoking initiation as a function of antecedent depressive symptoms and possible variation by subgroup.; The results suggested a modest independent association between depressive symptoms and subsequent smoking initiation among the adolescent students. Students with scores of depressive symptoms within the highest or middle tertile had a greater hazard of starting to smoke in the next grade compared to students with depression scores within the lowest tertile (HR: 1.6, 95% Cl: 1.2-2.3, p=0.002). This conclusion held true after adjustment for other suspected risk factors (aHR=1.5, 95% CI: 1.2-2.1, p=0.012). No significant subgroup variation of this association by gender or by intervention was found among the adolescent students.; In addition, the CC intervention trial conducted in first grade was estimated to be effective in preventing smoking initiation throughout adolescence. The CC intervention was associated with reduced risk of smoking initiation by 30% (aHR: 0.7, 95% Cl: 0.5-1.0, p=0.037). No evidence was found to support a prevention effect of the FSP intervention trial (aHR: 0.9, 95% Cl: 0.6-1.3, p=0.480).; This dissertation contributes to the literature by offering new epidemiological evidence of the association between depressive symptoms and later smoking initiation in adolescents. The prospective evidence highlights a possible causal influence of depressed mood on subsequent smoking initiation. Adolescents who are depressed may use tobacco to self-medicate their depressed mood, but other factors (e.g., genetic) may contribute to both depressed mood and smoking initiation.; The positive association between high levels of depressive symptoms and subsequent smoking initiation suggests that children and adolescents with depression should be targeted for smoking prevention intervention in clinical, community, or school settings. Education on adverse health effects of smoking may be combined with treatment of depression to motivate depressed adolescents to remain smoke-free. Adolescents who already smoke should also be screened for depression that may have preceded smoking initiation.; Future resear... |
