Causal Effects of Exposure to Social Media on Adolescent Mental Health

执行摘要 在过去的十年里，美国青少年的心理健康状况急剧下降。这些下降， 心理健康与社交媒体使用的增加相吻合，特别是在智能手机上。 然而，由于大多数现有的研究都是相关的，因此尚不清楚社交媒体的使用是否存在因果关系。 影响青少年心理健康。我们将通过开展第一次 纵向现场实验，以检查社交媒体对11-14岁青少年心理健康的因果影响。 我们提出了一个基本的实验，我们将招募500名11至14岁的青少年，他们的父母有 决定给他们买第一部智能手机青少年将被随机分配使用他们的 智能手机没有研究强加的社交媒体限制（自然主义社交媒体条件）或使用 三个月内不能使用社交媒体（社交媒体限制条件）。我们专注于 因为研究表明，大多数父母在这段时间给孩子买了第一部智能手机， 年龄范围和获得第一部智能手机与更多地接触社交媒体有关。我们 假设青少年在自然主义的社交媒体条件下会报告更大的焦虑症状 和抑郁症比青少年在社交媒体限制条件下。我们的实验设计也将 使我们能够为社交媒体对关键机制的因果影响提供证据， 未来的干预措施。我们假设移动的访问社交媒体将通过以下方式影响心理健康： 增加向上的社会比较，（B）取代睡眠、身体活动和面对面的社会互动， （3）影响人际交往的质量。超越自我报告的时间测量 在社交媒体上，我们将使用被动移动的传感（EARS工具）来获得客观的细粒度测量 青少年如何使用社交媒体。有证据表明，活跃的社交媒体（例如，消息传递、发布）使用 预测更好的心理健康，而被动的社交媒体使用（滚动，浏览）预测更差的心理健康 健康我们假设更积极地使用社交媒体的青少年将有更好的心理健康 结果。最后，最近的研究表明，虽然有些人经历了社会的负面影响， 媒体的使用，其他人没有体验到甚至是积极的影响。那些已经在努力指导和维持 他们的注意力特别容易受到移动的社交媒体的干扰。我们 假设处于自然主义社交媒体环境中的人在基线时注意力缺陷更大 焦虑和抑郁的症状会更严重我们还将探讨 年龄，性别，以及它们之间的相互作用。为了探索其他主持人的作用，我们将聘请一位 探索性机器学习方法，这将使我们能够探索多个 危险因素总之，我们的研究将是第一个实地实验，以因果检验社会媒体是否影响 青少年的心理健康，如果是这样，为什么，如何，以及对谁产生这种影响。

Executive Summary Adolescent mental health in the United States has declined precipitously in the past decade. These declines in mental health have coincided with an increase in social media use, especially as accessed on smartphones. Because most existing research is correlational, however, it is unclear whether social media use causally impacts adolescent mental health. We will advance scientific and public knowledge by conducting the first longitudinal field experiment to examine the causal effects of social media on mental health in 11–14-year-olds. We propose a basic experiment in which we will recruit 500 adolescents aged 11 to 14, whose parents have decided to purchase them their first smartphone. Adolescents will be randomly assigned to use their smartphones without study-imposed restrictions on social media (naturalistic social media condition) or to use them without access to social media for three months (restricted social media condition). We are focusing on this population because research shows that most parents buy their children their first smartphones during this age range and the acquisition of one’s first smartphone is linked to greater exposure to social media. We hypothesize that adolescents in the naturalistic social media condition will report greater symptoms of anxiety and depression than adolescents in the restricted social media condition. Our experimental design will also allow us to provide evidence for the causal impact of social media on key mechanisms, providing targets for future interventions. We hypothesize that mobile access to social media will affect mental health by (A) increasing upward social comparison, (B) displacing sleep, physical activity, and in-person social interactions, and (C) interfering with the quality of in-person social interactions. Going beyond self-report measures of time spent on social media, we will use passive mobile sensing (EARS tool) to get objective, fine-grained measures of how adolescents use social media. Evidence shows that active social media (e.g., messaging, posting) use predicts better mental health, whereas passive social media use (scrolling, browsing) predicts worse mental health. We hypothesize that adolescents who use social media more actively will have better mental health outcomes. Finally, recent research suggests that while some people experience negative effects of social media use, others experience no or even positive effects. Individuals who already struggle to direct and sustain their attention should be particularly vulnerable to the distracting effects of mobile social media. We hypothesize that people in the naturalistic social media condition with greater deficits in attention at baseline will show greater increases in symptoms of anxiety and depression. We will also probe the moderating role of age, gender, and their interaction. To explore the role of a range of other moderators, we will employ an exploratory machine-learning approach, which will allow us to explore the intersectionality between multiple risk factors. In sum, our study will be the first field experiment to causally test whether social media impacts younger adolescents’ mental health, and if so, why, how, and for whom such effects occur.