The effects of exposure to violence on risk for substance abuse: neural mechanisms and community level moderators

项目摘要 每年，多达40%的青少年在他们的社区目睹或经历过攻击。这种压力 暴露于暴力（EtV）大大增加了开始使用非法药物的可能性， 对他们上瘾。这项提议验证了EtV的压力重新校准神经过程的假设 潜在的情绪反应和调节，导致情感反应，冒险和 工作记忆这些心理变化，无论是独立的还是一致的，都会导致 物质使用的开始和升级。我们还假设EtV在多大程度上激发了这些 大脑和行为的变化高度依赖于EtV发生的环境背景， 因此，受社区层面因素（如集体效能、邻里经济 缺点），以及更传统的测量心理因素。为了测试这个多系统模型， EtV对物质使用的影响，我们将从我们正在进行的1500人的纵向发展研究中招募 富兰克林县的青少年，OH，一个子样本（n=600），将继续（在第2年和第5年;共4次 这些生态瞬时评估（EMA）、全球定位系统（GPS）和访谈评估 空间暴露于EtV和物质使用（包括客观的头发测量）。在2个额外的时间 点（1年和4年），青少年将完成一个全面的神经成像电池，包括 测量大脑结构，静息状态活动和神经活动，在4个良好的验证 神经认知任务，探索假设受到EtV影响的过程，并与 物质用途：（1）冒险行为;（2）奖励敏感性;（3）威胁反应性;和（4） 工作记忆为了支持我们将EtV与物质使用联系起来的理论，这些任务中的每一项都被证明是 受到EtV等压力体验的影响，以及经常使用药物的改变。针对性 从父母研究中招募将增加已经使用非法药物的青少年的比例， 物质以及经验丰富的EtV。目标1确定EtV和物质使用的独立影响 神经结构和功能的纵向变化以及横截面差异。目的2 决定了神经活动预测未来物质使用的程度。目标3评估程度， 哪些社区弹性和风险因素缓和了神经功能和结构的这些变化。例如 调节因素包括邻里和活动空间暴露（例如集体效能，暴力水平），家庭 社会过程和资源（如父母的监督，贫困）和生活史（幼儿期逆境） 因素通过纵向设计，我们将能够确定这些风险和 弹性因素修改了由EtV引起的神经变化的轨迹，这将提供新的 了解这些变量如何影响药物滥用风险，并提出干预目标， 社区，心理或神经水平，可能会防止或减弱EtV的持久影响。

Project Summary Each year, up to 40% of adolescents witness or experience an assault in their community. The stress of such exposures to violence (EtV) greatly increases the probability of initiating use of illicit drugs as well as becoming addicted to them. This proposal tests the hypothesis that the stress of EtV recalibrates the neural processes underlying emotional reactivity and regulation, which leads to changes in affect reactivity, risk-taking, and working memory. These psychological changes, either independently or in concert, lead to increased risk for the initiation and escalation of substance use. We also hypothesize that the degree to which EtV elicits these changes in brain and behavior is highly dependent on the environmental context in which EtV occurs and therefore moderated by community level factors (e.g. collective efficacy; neighborhood economic disadvantage) as well as more traditionally measured psychological factors. To test this multi-system model of EtV's effects on substance use, we will recruit from our ongoing, longitudinal developmental study of 1500 adolescents in Franklin County, OH, a subsample (n=600) that will continue (at years 2 and 5; 4 total time points) these ecological momentary assessment (EMA), global positioning (GPS), and interview assessments of spatial exposures to EtV and substance use (including objective head hair measures). At 2 additional time points (years 1 and 4), youths will complete a comprehensive neuroimaging battery that includes measurements of brain structure, resting state activity, and neural activity during 4 well-validated neurocognitive tasks that probe the processes hypothesized to be affected by EtV and associated with increased risk for substance use: (1) risk-taking behavior; (2) reward sensitivity; (3) threat reactivity; and (4) working memory. In support of our theory linking EtV to substance use, each of these tasks has been shown to be impacted by stressful experiences like EtV as well as altered by regular substance use. Targeted recruitment from the parent study will enhance the proportion of youths who have already used illicit substances as well as experienced EtV. Aim 1 determines the independent effects of EtV and substance use on longitudinal changes in neural structure and function as well as cross-sectional differences. Aim 2 determines the degree to which neural activity predicts future substance use. Aim 3 evaluates the degree to which community resilience and risk factors moderate these changes in neural function and structure. Example moderators include neighborhood and activity space exposures (e.g. collective efficacy, violence levels), family social processes and resources (e.g. parental monitoring, poverty), and life history (early childhood adversity) factors. With a longitudinal design, we will be able to determine the temporal ordering of how these risk and resilience factors modify the trajectory of neural changes resulting from EtV, which will provide new understanding of how these variables influence substance abuse risk and suggest targets for intervention at the community, psychological, or neural level that might prevent or attenuate the enduring effects of EtV.