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水平急剧下降。这些下降在 心理健康与社交媒体使用的增加不谋而合，特别是在智能手机上访问社交媒体的时候。 然而，由于大多数现有研究都是相关的，所以尚不清楚社交媒体的使用是否存在因果关系 影响青少年的心理健康。我们将通过开展第一次 研究社交媒体对11-14岁青少年心理健康影响的纵向现场实验。 我们提出了一个基本的实验，我们将招募500名11到14岁的青少年，他们的父母已经 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 未经研究的智能手机--对社交媒体施加限制(自然主义的社交媒体条件)或使用 他们在三个月内无法访问社交媒体(社交媒体受限条件)。我们专注于 这是因为研究表明，大多数父母在这段时间给孩子买了第一部智能手机 年龄范围和购买第一部智能手机与更多地接触社交媒体有关。我们 假设处于自然主义社交媒体状态的青少年会报告更多的焦虑症状 在受限制的社交媒体条件下，青少年比青少年更容易患抑郁症。我们的试验性设计也将 使我们能够为社交媒体对关键机制的因果影响提供证据，为 未来的干预措施。我们假设移动访问社交媒体将通过(A)影响心理健康 增加向上的社会比较，(B)取代睡眠、体力活动和面对面的社交互动， 以及(C)干扰面对面社交互动的质量。超越自我报告的时间衡量标准 在社交媒体上花费，我们将使用被动移动感知(EAR工具)来获得客观、细粒度的测量 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、发帖)使用 被动使用社交媒体(滚动、浏览)预示着更好的心理健康，而消极使用社交媒体则预示着更糟糕的心理 健康。我们假设，更积极使用社交媒体的青少年会有更好的心理健康 结果。最后，最近的研究表明，尽管一些人经历了社交网络的负面影响 媒体的使用，其他人则没有甚至是积极的影响。已经在努力指导和维持的个人 他们的注意力应该特别容易受到移动社交媒体分散注意力的影响。我们 假设处于自然主义社交媒体状态的人在基线时注意力缺陷更大 会在焦虑和抑郁症状上表现出更大的增加。我们还将探讨 年龄、性别及其相互作用。为了探索一系列其他主持人的作用，我们将聘请 探索性机器学习方法，它将使我们能够探索多个 风险因素。总而言之，我们的研究将是第一次对社交媒体的影响进行因果检验的现场实验 青少年的心理健康，如果是这样的话，为什么、如何以及对谁会产生这种影响。

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.