Trajectories of reward sensitivity and depression across adolescence

描述（由申请人提供）：越来越多的关注发生在青春期的奖励敏感性的变化；特别是，青春期似乎是一个对奖励更加敏感的时期。与此同时，青春期的特点是抑郁症状显著增加，而抑郁症的特点是对奖励的敏感性降低。目前的项目将奖励敏感性作为一种潜在的特征来研究，结合了脑电图、功能神经成像（fMRI）、行为和自我报告测量。沿着同样的思路，我们考虑对抑郁症状的多重评估（例如，父母和孩子的报告），这样抑郁症状也可以被建模为一种潜在的特征。目前的提议在一个9到14岁的女孩的大样本（N=300）中研究了奖励敏感性和抑郁；此外，该样本将在初次访问两年后进行检查，以便可以检查横截面和纵向关系。在我们的试点数据中，我们广泛关注反馈相关的负性（FRN），在反馈后大约300毫秒，在头皮上观察到的皮层电反应是明显的负性，表明金钱损失与收益相比。我们的研究表明，获得和损失之间的神经分化是由与奖励相关的正电位驱动的，该电位产生于基底神经节的腹侧纹状体，该纹状体与奖励相关的神经回路有关。我们发现FRN与基于fmri的纹状体对奖励的反应以及奖励敏感性的行为指标有关。此外，我们发现，FRN在成年人和更抑郁的青少年中都有所减少，最近还发现，与奖励相关的大脑活动减少可以预测青少年两年内抑郁症状的变化。目前的建议将这项工作扩展到一个更大的纵向样本，并纳入了奖励敏感性、抑郁症状和青春期的多种测量方法。我们将评估：a)在跨越青春期的两个时间点的大样本中，奖励敏感性的多种测量与抑郁症状之间的关系，间隔2年（目的1）；b)奖励敏感性和抑郁症状的规范性发育增加，特别是作为青春期阶段的功能（目标2）；c)奖励敏感性与抑郁症状之间随时间推移的前瞻性关系，以及首次评估时的奖励敏感性是否可以预测两年后抑郁的变化（目标3）；最后，如果青春期的变化预示着奖励敏感性和后来的抑郁症状之间有更强的联系（目的3）。一些次要目标也被评估（例如，对抑郁症状的特异性，而不是焦虑症状；唾液睾酮作为青春期阶段标志的效用；压力生活事件的作用）。这个

DESCRIPTION (provided by applicant): There is increasing focus on changes in reward sensitivity that take place across adolescence; in particular, puberty appears to be a time characterized by increased sensitivity to rewards. At the same time, puberty is a time characterized by a significant increase in depressive symptoms, and depression is characterized by reductions in sensitivity to rewards. The current project examines reward sensitivity as a latent trait, capitalizing on a combination of EEG, functional neuroimaging (fMRI), behavioral, and self-report measures. Along the same lines, we consider multiple assessments of depressive symptoms (e.g., parent and child reports) so that depressive symptoms can also be modeled as a latent trait. The current proposal examines both reward sensitivity and depression in a large (N=300) sample of girls, ranging from 9 to 14 years of age; moreover, this sample will be examined two years after the initial visit, so that both cross-sectional and longitudinal relationships can be examined. In our pilot data, we have focused extensively on the feedback-related negativity (FRN), an electrocortical response observed at the scalp as an apparent negativity approximately 300 ms following feedback indicating monetary loss compared to gain. Our work suggests that the neural differentiation between gains and losses is being driven by a reward-related positive potential that is generated in the ventral striatum-part of the basal ganglia that has been implicated in reward-related neural circuits. We have found that the FRN relates to fMRI-based measures of striatal response to rewards, as well as behavioral metrics of reward sensitivity. Moreover, we have found that the FRN is reduced in both adults and adolescents who are more depressed-and have recently found that reduced reward-related brain activity can predict changes in depressive symptoms over the course of two years among adolescents. The current proposal extends this work into a much larger and longitudinal sample, and incorporates multiple measures of reward sensitivity, depressive symptoms, and puberty. We will assess: a) the relationship between multiple measures of reward sensitivity and depressive symptoms in a large sample that spans adolescence at two time points, separated by 2 years (Aim 1); b) normative developmental increases in both reward sensitivity and depressive symptoms, especially as a function of pubertal stage (Aim 2); c) prospective relations between reward sensitivity and depressive symptoms over time, and whether reward sensitivity at the first assessment can predict changes in depression two years later (Aim 3); finally, if pubertal changes predicts a stronger link between reward sensitivity and later depressive symptoms (Aim 3). A number of secondary aims are also evaluated (e.g., specificity to depressive symptoms and not anxious symptoms; utility of salivary testosterone as a marker of pubertal stage; role of stressful life events). The present study will contribute to the literature on the developmental neurobiology of reward, as well as the neurobiological changes related to individual differences in depression and risk for depression across adolescence. PUBLIC HEALTH RELEVANCE: We examine the role of pubertal stage and change on reward sensitivity (RS; measured using behavioral, ERP, fMRI, and self-report methods) and depressive symptoms among 300 females (aged 9 to 14) in a time-sequential design-and evaluate if low RS can predicts depression.