Initiating Substance Use in Adolescence: Associations with rCBF

描述(由申请人提供)：拟议的项目将利用独特的机会，在物质使用之前或早期阶段调查青少年，以确定与开始使用有关的基于大脑的生物标记物、使用的严重性和使用随时间的轨迹，以及使用对发育中的大脑的影响。现有的横断面和纵向数据集(R01AA016274和ROIMH87493)包括330名青少年(12-15岁)基线和264名(14-17岁)两年随访时的行为测量和神经成像数据。使用物质使用严重程度的一般指数(尝试两种或两种以上物质的报告，Su2+)对基线的ASL-MRI图像进行初步分析表明，与戒毒者(98例)相比，SU2+青少年(n=21)的静息局部脑血流量增加。拟议的工作将(1)包括更多合格的严重性指标，以澄清与rCBF的关联，(2)确定基线皮质边缘rCBF是否与未来两年临床随访中的物质使用有关，以及(3)慢性物质使用对发育中大脑的影响。除了样本的独特性和丰富性外，专注于静息rCBF对于研究发育中的大脑是理想的，因为在发生血管生成、突触形成或其他神经发育过程的大脑区域需要血液流动。然而，到目前为止，局部脑血流量(RCBF)的定量测量仅限于成年人。此外，对物质使用的神经成像研究仅限于成人、慢性使用者。因此，这项研究的结果将是这个年龄段的第一个报告，特别是在rCBF与物质使用有关的情况下。

DESCRIPTION (provided by applicant): The proposed project will take advantage of the unique opportunity to investigate adolescents prior to or at the early stages of substance use to identify brain-based biomarkers associated with initiation of use, the severity of use and the trajectory of use over time, and the impact of use on the developing brain. The existing, cross- sectional and longitudinal data set (R01AA016274 and ROIMH87493) includes behavioral measures and neuroimaging data for 330 adolescents (age 12-15) at baseline and 264 (age 14-17) at two-year follow-up. Preliminary analyses of ASL-MRI images at baseline using a general index of substance use severity (report of trying two or more substances, SU2+) indicate that resting regional cerebral blood flow to cortico-limbic brain regions is elevated in SU2+ adolescents (n=21) relative to those who were abstinent (n=98). The work proposed will (1) include more qualified severity metrics to clarify associations with rCBF, (2) determine whether baseline cortico-limbic rCBF is associated with future substance use over the two-year clinical follow- up, and (3) the effects of chronic substance use on the developing brain. In addition to the uniqueness and richness of the sample, the focus on resting rCBF is ideal for studying the developing brain as blood flow is required in brain regions where angiogenesis, synaptogenesis or other processes of neurodevelopment are occurring. However, to date quantitative measure of regional cerebral blood flow (rCBF) has been restricted to adult populations. As well, neuroimaging studies of substance use have been limited to adult, chronic users. Therefore, the outcomes produced from this study will be the first reported in this age group, particularly as rCBF relates to substance use.