Adolescent Drug Use: Exploring Neurocognitive Precursors

描述（由申请人提供）： 成年人的物质使用障碍通常在青春期发病，较早发病预示着随后的依赖和滥用。我们在这方面的长期目标是通过更好地了解青少年早期开始使用药物的前兆来减少药物使用障碍。我们建议探索早期物质使用的神经认知前体，假设特定的神经认知特征将预测青少年吸毒轨迹。我们的目标是探索前额叶皮层（PFC）的功能，因为PFC是值得注意的，其出生后的成熟期延长，并参与决策，自我调节和冲动-青少年和物质使用者的共同特征。本研究是一项为期5年的多队列观察性纵向研究，主要目的是：（1）绘制前额叶认知功能的发展轨迹图;（2）研究实验室测量的前额叶认知功能与冲动性之间的关系，绘制冲动性的发展轨迹图;以及3）研究前额叶皮层功能和冲动性在早期药物使用和各种青少年药物使用轨迹中的作用。在城市混合社会经济地位样本中，将入组3组175例受试者，年龄分别为10岁、11岁和12岁，共计525例受试者。每组将随访5年。在四种情况下，受试者将接受一系列神经认知任务和冲动性测量，完成风险行为评估、青春期阶段自我评估，并提供尿液样本用于药物筛选。主要的数据分析策略将使用混合模型来计算前额叶皮层和冲动性以及药物使用开始的不同发展轨迹。在项目结束时，我们预计青少年药物使用的神经认知前体的理解。这反过来将为制定预防战略提供基础设施。

DESCRIPTION (provided by applicant): Substance use disorders in adults commonly have their onset in adolescence, with earlier onset predicting subsequent development of dependency and abuse. Our long-term objectives here are reduction of substance use disorders through an improved understanding of the precursors of early initiation of substance use by adolescents. We propose exploration of the neurocognitive precursors of early substance use, hypothesizing that particular neurocognitive characteristics will predict adolescent drug-use trajectories. We target exploration of prefrontal cortex (PFC) function, as the PFC is notable for its prolonged period of postnatal maturation and for its involvement in decision-making, self-regulation, and impulsivity -- traits common to adolescents and to substance users. This 5-year investigation, designed as a multicohort observational longitudinal project, proposes the following specific aims: 1) to map the developmental trajectory of prefrontally-mediated cognitive functions; 2) to examine the relation between laboratory measures of prefrontal cognitive functions and measures of impulsivity, and to map the developmental trajectory of impulsivity; and 3) to investigate the role of prefrontal cortex function and impulsivity in early drug use and in various adolescent drug-use trajectories. In an urban, mixed socioeconomic status sample, three groups of 175 subjects will be enrolled at the following ages 10, 11, and 12 years, for a total of 525 subjects. Each group will be followed for 5 years. On four occasions subjects will be administered a battery of neuro-cognitive tasks and measures of impulsivity, will complete an assessment of risk behaviors, a self-assessment for pubertal stage, and provide a urine sample for drug screening. The major data analysis strategy will use mixture models to calculate differential trajectories of development of the prefrontal cortex and impulsivity as well as drug use initiation. At project end we anticipate improved understanding of the neurocognitive precursors of adolescent drug use. This, in turn, will provide an infrastructure for developing prevention strategies.