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，发病较早预示着随后会发展成依赖和滥用。我们在这里的长期目标是通过更好地了解青少年早期开始使用物质的前兆来减少物质使用障碍。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药物使用轨迹。我们的目标是探索前额叶皮质(PFC)的功能，因为PFC以其出生后成熟期较长以及参与决策、自我调节和冲动--青少年和物质使用者的共同特征--而闻名。这项为期5年的研究是一项多队列纵向观察项目，它提出了以下具体目标：1)绘制前额叶调节的认知功能的发展轨迹；2)检查前额叶认知功能的实验室测量与冲动测量之间的关系，并绘制冲动的发展轨迹；以及3)调查前额皮质功能和冲动性在早期吸毒和青少年吸毒轨迹中的作用。在一个混合的城市社会经济状况样本中，175名受试者将在10岁、11岁和12岁以下的三组中登记，总共525名受试者。每组随访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测量，完成危险行为评估，青春期自我评估，并提供用于药物筛选的尿样。主要的数据分析策略将使用混合模型来计算前额叶皮质的发育和冲动性以及药物使用开始的差异轨迹。在项目结束时，我们期待对青少年药物使用的神经认知前体有更好的理解。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.