INNOVATIVE LATENT CURVE MODELS OF ADOLESCENT DRUG USE

拟议的研究项目是由一名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，以确定目前难以经验性评估的重要研究问题，这些问题将从新的量化方法的发展中受益匪浅。该提案围绕三个主要目标进行组织。首先，将开发一类关于个体随时间变化差异的创新纵向模型，明确的目的是允许对物质使用的发展轨迹进行强大、灵活和动态的经验测试。这些新模型将允许估计各种多变量潜在曲线模型，这些模型对非正态和模型错误指定更稳健，在预测后续问题行为时纳入潜在增长因素之间的双向和三向交互作用，并同时检查重要生命转变前后多个发展轨迹的特征。其次，将密切评估这些新的定量方法的有效性和实用性，特别强调未来在物质使用研究中的应用。对这些新模型的评估将主要通过使用全面的计算机模拟来完成，这些计算机模拟将重点放在药物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、多变量非正态分布和模型误指定。第三，这些新模型将被应用于现有的高质量纵向数据集，以检查在大样本青少年中行为问题和物质使用的共同发展轨迹的过程、原因和后果。数据将来自一项现有的纵向研究，该研究对1000多名9岁至18岁的青少年进行了为期四年的每年一次评估。将新开发的定量方法应用于这些数据，将允许对一些理论推导的研究假说进行详细评估，包括关于物质使用和品行问题随时间的相互发展关系、行为问题和物质使用轨迹之间的相互作用在预测以后的问题行为方面的问题，以及学校和青春期转变对这些发展轨迹的影响。经验性应用还将用于向应用物质使用研究人员的广泛受众演示和传播新开发的模型。拟议项目的统一目标是集中更多的努力，明确将定量方法论和应用发展精神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，这些模型最适合研究随着时间的推移药物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.