Quantifying Exposure to Illicit Drugs & Psychosocial Stress in Real Time

对吸毒和社会心理压力的评估是复杂的，因为它们往往都是短暂的，很难准确回忆。由于因果联系的复杂性和构成环境的难以捉摸的性质，对它们彼此之间的因果联系以及它们的遗传和环境决定因素的评估是复杂的。 在这个项目中，我们通过生态瞬间评估(EMA)近乎实时地评估药物使用和心理社会压力，在EMA中，参与者使用手持电子日记记录事件发生时，并根据全天随机定时的提示报告最近或正在发生的事件。我们还通过让参与者携带全球定位系统(GPS)记录器，以几米的空间分辨率跟踪他们的下落，从而保持对报告事件发生地点的实时记录。我们在一种我们称为地理瞬时评估(GMA)的方法中集体使用这些数据。我们与GMA的目标与了解巴尔的摩发生毒品相关行为的具体地点几乎没有关系，而是要获得关于活动空间(发生日常活动的空间)如何与此类行为及其沉淀物相关联的概括性知识。为此，我们根据客观统计数据对邻近环境进行评分，并更具创新性地根据训练有素的观察员的客观评分进行评分。对于许多成瘾研究人员，如行为遗传学家和药理学临床试验者，这些环境措施将构成需要控制的噪音，因此GMA对他们的好处将是帮助分离感兴趣的生物措施。对于专注于社会科学的成瘾研究人员来说，环境措施将是信号而不是噪音，因此GMA的好处将是为环境干预提供理由，并提供一种严格的方法来评估干预的实施和有效性。 为了增加现场方法的客观性，我们增加了对呼吸、心率变异性和皮肤电反应等生理功能的动态监测。我们对这些措施的目标包括开发能够自动检测行为事件(如吸毒或压力发作)的算法，而不需要自我报告。 为了帮助验证我们的现场方法，我们正在收集所有参与者每周三次的尿样，并通过标准化的实验室程序评估他们的特质应激反应。 我们这组项目的六个出版物都使用了我们完成的第一个这样的项目的数据，那是一项没有纳入GPS的EMA研究。在最新的研究报告中，我们发现滥用可卡因和海洛因的门诊患者在工作场所的压力更小，幸福感更强(对毒品的渴求也更少)。这是一个令人惊讶的结果，与在普通人群中可靠地发现的正好相反。我们不能轻易地从这一非实验发现中得出因果结论，但我们确实得出结论，实验干预是必要的。我们继续分析第一项EMA研究的数据，但我们的重点是完成一项更大的研究，该研究将GPS与其他EMA压力测量方法结合在一起。

Assessment of exposure to drug use and psychosocial stress is complicated by the fact that each is often transient and difficult to recall accurately. Assessment of their causal connections with one another, and of their genetic and environmental determinants, is complicated by the complexity of the causal connections and by the elusive nature of what constitutes the environment. In this project, we are assessing drug use and psychosocial stress in near-real time through Ecological Momentary Assessment (EMA), in which participants use handheld electronic diaries to record events as they occur and to report recent or ongoing events in response to randomly timed prompts throughout the day. We are also maintaining real-time records of where the reported events occur by having participants carry Global Positioning System (GPS) loggers to track their whereabouts with a spatial resolution of several meters. We use these data collectively in a method we are calling Geographical Momentary Assessment (GMA). Our goal with GMA has little to do with knowing the specific Baltimore locations where drug-related behaviors occur, and everything to do with gaining generalizable knowledge about how activity spaces (the spaces in which daily activities occur) are associated with such behaviors and their precipitants. To that end, we score neighborhood environments in terms of objective statistical data andmore innovativelyin terms of objective ratings by trained observers. For many addiction researchers, such as behavioral geneticists and pharmacological clinical trialists, these environmental measures will constitute noise to be controlled for, so the benefit of GMA to them will be to help isolate the biological measures of interest. For addiction researchers with a social-science focus, the environmental measures will be signal rather than noise, so the benefit of GMA will be to make a case for environmental interventions and to provide a rigorous way of assessing the interventions implementation and effectiveness. To increase the objectivity of our field methods, we have added ambulatory monitoring of physiological functions such as respiration, heart-rate variability, and galvanic skin response. Our goals for these measures include the development of algorithms that can automatically detect behavioral events (such as episodes of drug use or stress) without requiring self-report. To help validate our field methods, we are collecting thrice-weekly urine specimens from all our participants and assessing their trait stress reactivity through standardized laboratory procedures. Our six publications from this set of projects have all used data from the first such project we completed, which was an EMA study that did not incorporate GPS. In the most recent of those publications, we showed that our cocaine- and heroin-abusing outpatients reported less stress and greater happiness (and less drug craving) at the workplace than in any other setting. This was a surprising result, precisely opposite to what has been reliably found in the general population. We do not facilely draw causal conclusions from this non-experimental finding, but we do conclude that experimental interventions are warranted. We continue to analyze data from our first EMA study, but our focus is on completing a larger study that incorporates GPS along with additional EMA measures of stress.