Anhedonia as a Risk Factor and Consequence of Substance Use

描述（由申请人提供）：物质使用是可预防的死亡和残疾的主要原因。物质使用通常在青春期开始和发展。因此，确定青少年药物使用开始和进展的新风险因素可能会为制定创新的预防干预措施提供信息，以减少药物使用的公共卫生负担。快感缺失是一种情感维度，表明对奖励的兴趣和快乐减少，最近被认为是物质使用的相关因素。 然而，现存文献中的关键空白阻止了对快感缺失与物质使用关系的研究对该领域产生实质性影响。例如，现有的研究已经完全是横截面的，并没有解析出共同的前因和背景因素的作用，离开这种关联的因果特征不清楚。此外，过去的工作主要是研究成年人，只有三个出版的青少年快感缺乏物质使用关系的研究，这些研究都受到严格的限制。此外，以往的研究都只使用了基于主观报告的单一测量快感缺失，这忽略了快感缺失结构的多方面性质。阐明物质使用中快感缺失不同方面的相对作用对于设计新的预防计划至关重要，这些计划可以提高对健康替代非药物强化的兴趣的享乐反应。此外，这些文献已经大大脱节和理论，没有以前的努力，以整合到一个统一的模型内的风险更大的概念化的研究结果。然而，重要的是模型，以确定理论机制，快感缺乏增加物质使用风险的发展途径，从使用开始到进展，以推进基础理论和干预发展。这种研究是至关重要的，以推动发展物质使用预防干预措施，目标快感缺失。 因此，我们提出了一个纵向研究，以测试一个新的综合模型的基础上的假设，该模型预测，快感缺失引起的因果风险途径，影响物质使用的启动和进展，通过正强化机制。该模型认为，具有较高快感缺失的个体期望物质会产生积极的效果，并愿意使用物质，这可能会促进物质使用的启动。一旦开始使用，高快感缺失个体可能对药物的急性主观奖励效应更敏感，这可能进一步降低非药物奖励的相对显着性，并导致替代强化的参与度下降。这两个因素可能会在药物相关与替代强化的价值之间产生强烈的不平衡，这可能会推动再次使用的动机，并增加物质使用进展的可能性。这些途径可能是特别突出的那些伴随的特点，促进表达快感缺乏的影响动机开始和进展物质使用。一旦建立了持续的使用，重复的药物暴露可能会导致心理生物学适应，进一步加剧快感缺失，重演这个周期，并导致更多的使用。 本研究以2007名高中生为研究对象，采用纵向研究方法，对九至十二年级学生进行八次自我报告评估，每半年一次。评估将在学校环境中进行，这将促进有效和高效的数据收集，并将涵盖自我报告措施和快感缺乏的客观行为措施。本研究的主要目的是检验以下假设：（1）快感缺失将前瞻性地预测无既往使用史的患者开始使用药物，（2）快感缺失将前瞻性地预测药物使用进展，（3）使用频率增加将前瞻性地预测快感缺失随时间的增加。次要目标是积极的强化机制，调解和缓和的快感缺乏对物质使用风险的影响，来自该模型。 从这项研究中获得的信息可能是开发新的，更有效的预防策略，提高体验的乐趣和积极的强化，以防止物质使用的显着价值。这些努力最终可减轻药物使用障碍造成的巨大公共卫生负担。 公共卫生相关性：这项研究将有助于确定是否有快感缺乏心理特征的青少年（即，倾向于不喜欢或对愉快的活动不感兴趣）在高中期间使用酒精，毒品和烟草的风险更大。该研究的结果可以为新预防计划的制定提供信息，这些计划强调增强生活乐趣以预防青少年药物使用问题的重要性。由于与药物使用相关的巨大健康成本，此类信息可能对改善公共健康的努力具有重大价值。

DESCRIPTION (provided by applicant): Substance use is a leading cause of preventable death and disability. Substance use typically onsets and progresses during adolescence. Thus, identifying novel risk factors for adolescent substance use initiation and progression may inform the development of innovative preventive interventions that reduce the public health burden of substance use. Anhedonia-an affective dimension indicative of diminished interest and pleasure in rewarding-has been recently identified as a correlate of substance use. However, critical gaps in the extant literature prevent research on anhedonia's relation with substance use from having a substantial impact on the field. For example, existing research has been entirely cross-sectional and has failed to parse out the role of common antecedents and contextual factors, leaving the casual features of this association unclear. Also, past work has primarily studied adults, with only three published studies of anhedonia-substance use relations in adolescents; each of these studies are subject to critical limitations. Furthermore, each prior study has used only a single measure anhedonia based on subjective report, which ignores multi-faceted nature of the anhedonia construct. Elucidating the relative roles of distinct facets of anhedonia in substance use is critical for designing novel prevention programs that raise hedonic response to an interest in healthy alternative non-drug reinforces. Additionally, this literature has been greatly disjointed and theoretical, with no previous effort to integrate findings into a unifying model within larger conceptualization of risk. Yet, it is important for models to identify theoretial mechanisms by which anhedonia increases substance use risk in a developmental pathway from use initiation to progression in order to advance basic theory and inform intervention development. Such research is critical in order to move forward with developing substance use preventive interventions that target anhedonia. Accordingly, we propose a longitudinal study to test hypotheses based on a novel integrative model, which predicts that anhedonia gives rise to a causal risk pathway that influences both substance use initiation and progression via positive reinforcement mechanisms. This model purports that individuals with higher anhedonia have expectations that substances will produce positive effects and are willing to use substances, which could promote substance use initiation. Once use is initiated, high-anhedonia individuals may be more sensitive to the acute subjective rewarding effects of drugs, which may further devalue the relative salience of non-drug rewards and result in declining engagement in alternative reinforces. These two factors may create a strong imbalance between the value of drug-related versus alternative reinforces, which may drive motivation to use again and increase likelihood of substance use progression. These pathways may be particularly prominent for those with concomitant characteristics that facilitate the expression of anhedonia's influence on motivation to initiation and progress substance use. Once consistent use is established, repeated drug exposure may cause psychobiological adaptations that further escalate anhedonia, recapitulate this cycle, and lead to more use. In this study, we will recruit a cohort f 2007 high school students to participate in a longitudinal study with 8 semiannual waves of self-report assessment (9th - 12th grades). Assessments will take place in the school setting, which will facilitate efficient and effective data collection, and will span both self-report measures an objective behavioral measures of anhedonia. The primary aims of the study are to test the hypotheses that: (1) anhedonia will prospectively predict substance use initiation among those with no prior history of use, (2) anhedonia will prospectively predict substance use progression, and (3) Greater frequency of use will prospectively predict increases in anhedonia over time. Secondary aims will positive reinforcement mechanisms that mediate and moderate the effects of anhedonia on substance use risk that are derived from the model. The information gained from this study could be of significant value to developing novel, more effective prevention strategies that enhance experiential pleasure and positive reinforcement to prevent substance use. Such efforts could ultimately allay the substantial public health burden caused by substance use disorders. PUBLIC HEALTH RELEVANCE: This study will help determine whether adolescents who have the psychological trait of anhedonia (i.e., the tendency to not enjoy or be interested in pleasurable activities) are at greater risk for using alcohol, drugs, and tobacco during high school. The study's results could inform the development of new prevention programs that stress the importance of enhancing life pleasure to prevent substance use problems in youths. Because of the enormous health costs associated with substance use, such information could be of significant value to efforts to improve public health.