This application requests support to conduct research using an innovative integrative data analysis (IDA) method to pool three independent, national level data sets and to use newly developed statistical methods to evaluate DSM-IV symptoms in recent onset smokers with varying levels of current smoking exposure in order to develop a novel measure of ND symptoms that is optimally valid and reliable for this understudied population. For some, symptoms of nicotine dependence (ND) emerge soon after smoking initiation, at low levels of smoking, and before daily smoking. These early emerging symptoms are related to future smoking after controlling for current levels of exposure. Careful measurement of this construct among novice smokers across the continuum of non-daily and daily smoking levels is vital for gaining a better understanding of ND. This work has been severely impeded by the fact that existing studies of adolescent and young adult smoking behavior provide small sample sizes that prohibit careful examination of the psychometric properties of ND symptoms across the full range of smoking experiences. IDA will be used to overcome these limitations by pooling data from the 1999 and 2000 National Survey on Drug Use and Health (NSDUH) and from the Wave 1 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). The pooled data will be used to evaluate differences in DSM-IV ND symptom properties in individuals aged 12-25 who began smoking within the past two years and who represent the full continuum of smoking exposure. The following aims will be addressed: 1) Evaluate psychometric properties of the DSM-IV nicotine dependence symptoms and assess invariance in DSM-IV dependence symptom properties across studies and across demographic subgroups; 2) Determine the extent to which nicotine dependence symptom properties differ as a function of level of smoking exposure, controlling for study characteristics and other moderators such as age, gender, SES and ethnicity; and 3) Conduct a sensitivity analysis where the relation between ND and alcohol use, abuse and dependence is examined for individuals with similar levels of smoking exposure, using the empirically derived ND scores from Aims 1 and 2 and traditional ND scoring methods. A novel statistical method, moderated nonlinear factor analysis (MNLFA), will be used to conduct a rigorous psychometric assessment of the ND symptoms. Parameter estimates from the MNLFA will be used to obtain optimal ND symptom scores to be used in later regression analyses evaluating the association between alcohol use and these scores. Results will be compared to those obtained using traditional ND scoring methods. Sub aims will provide a more rigorous test of these methods by testing the primary aims using a pooled data set that also includes the 2008 NSDUH and combines symptoms from DSM-IV and the Nicotine Dependence Syndrome Scale. The proposed research is expected to inform further development of a highly accurate assessment to identify recent onset smokers along the full continuum of current smoking exposure at greatest risk for continued and heavier smoking.