INNOVATIVE LATENT CURVE MODELS OF ADOLESCENT DRUG USE

拟议的研究项目是一个年轻的研究人员首次提交的R01申请。 该项目直接借鉴物质使用和行为问题的发展理论，以确定目前难以进行经验评估的重要研究问题，并将大大受益于新的定量方法的发展。 该提案围绕三个主要目标展开。 首先，一类新的创新的纵向模型的个人差异的变化随着时间的推移，将开发与明确的目的，允许强大的，灵活的和动态的实证测试的发展轨迹的物质使用。 这些新的模型将允许各种多变量潜在曲线模型的估计，这些模型对非正态性和模型误设更鲁棒，在预测后期问题行为时纳入潜在生长因子之间的双向和三向相互作用，并同时检查重要的生活转变前后的多个发展轨迹的特征。 第二，这些新的定量方法的有效性和实用性将密切评估，特别强调未来的应用研究的物质使用随着时间的推移。 这些新模型的评价将主要通过使用全面的计算机模拟来完成，这些模拟将集中在物质使用和滥用的应用纵向研究中经常遇到的有限抽样特征，包括小样本量，多变量非正态性和模型错误指定。 第三，这些新的模型将被应用到一个高质量的现有的纵向数据集，以检查过程中，原因和后果的共同发生的发展轨迹的行为问题和物质使用的大样本的青少年。 数据将从现有的1000多名青少年的纵向研究中提取，这些青少年的年龄从9岁到18岁不等，每年评估一次，为期四年。 新开发的定量方法对这些数据的应用将允许对一些理论推导的研究假设进行详细评估，包括关于物质使用和行为问题之间随着时间的推移的相互发展关系的问题，行为问题和物质使用的轨迹之间的相互作用，以及学校和青春期过渡对这些发展轨迹的影响。 实证应用也将有助于展示和传播新开发的模型，以广泛的受众应用物质使用的研究人员。 拟议项目的统一目标是将扩展的努力集中在明确地将定量方法学和应用发展心理病理学领域联系起来，以创建和传播一类新的创新统计模型，这些模型最适合于研究随着时间的推移物质使用发展轨迹的个体差异。

The proposed research project is a first submission of an R01 application by a young investigator. The project draws directly upon developmental theories of substance use and conduct problems to identify important research questions that are currently difficult to evaluate empirically and would greatly benefit from the development of new quantitative methodologies. The proposal is organized around three major goals. First, a new class of innovative longitudinal models of individual differences in change over time will be developed with the explicit purpose of allowing powerful, flexible and dynamic empirical tests of developmental trajectories of substance use. These new models will allow for the estimation of a variety of multivariate latent curve models that are more robust to non-normality and model misspecification, that incorporate two- and three-way interactions among latent growth factors in the prediction of later problem behaviors, and that simultaneously examine characteristics of multiple developmental trajectories before and after important life transitions. Second, the validity and utility of these new quantitative methods will be closely evaluated with particular emphasis on future applications in studies of substance use over time. Evaluation of these new models will primarily be accomplished through the use of comprehensive computer simulations that will focus on finite sampling characteristics that are commonly encountered in applied longitudinal research of substance use and abuse including small sample size, multivariate non-normality, and model misspecification. Third, these new models will be applied to a high quality existing longitudinal data set to examine the course, causes and consequences of co-occurring developmental trajectories of conduct problems and substance use in a large sample of adolescents. Data will be drawn from an existing longitudinal study of over 1000 adolescents ranging in age from 9 to 18 assessed once a year for four years. Application of the newly developed quantitative, methods to this data will allow for a detailed evaluation of a number of theoretically derived research hypotheses including questions about reciprocal developmental relations between substance use and conduct problems over time, interactions between trajectories of conduct problems and substance use in the prediction of later problem behavior, and the effects of school and pubertal transitions on these developmental trajectories. The empirical applications will also serve to demonstrate and disseminate the newly developed models to a wide audience of applied substance use researchers. The unifying goal of the proposed project is to focus extended effort on explicitly linking the fields of quantitative methodology and applied developmental psychopathology to create and disseminate a new class of innovative statistical models that are optimally suited for studying individual differences in developmental trajectories of substance use over time.