Social Media Mechanisms Affecting Adolescent Mental Health (SoMe3)

Adolescents estimate that they spend just under 5 hours online every day. This is almost as much time as they spend at school, with the average UK school day lasting 6.5 hours. Adolescent mental health has also declined substantially over the last decade, putting large-scale pressures on UK health services, society and the economy. This has made many concerned that digitalisation is actively damaging adolescent mental health. However, we still know relatively little about whether such concerns are warranted. This is a scientific supply issue highlighted by both the President of the Royal College of Psychiatrists ("We desperately need more research into the benefits and harms of technology use") and the UK Chief Medical Officers ("...more comprehensive research should be supported by health bodies and research institutions. An appropriate mechanism for measuring children's digital engagement needs to be developed...").

A lot of research on digitalisation and adolescent mental health has focused on social media, a particularly high-risk digital innovation. Social media is used heavily by the adolescent population (94% of 16-17s have a social media profile) and introduces changes to the social environment that could amplify pre-existing vulnerabilities. For example, peer rejection is especially salient in adolescence, and a mental health risk factor. Social media quantifies the social feedback adolescents receive from peers through 'like' counts, which could increase the salience of social feedback such as rejection, and therefore increase mental health risk (Mechanism A). Further social media allows for continued access to peers, which is very attractive to adolescents. This can lead to habitual social media use and self-control failures that impact mental health directly and indirectly (Mechanism B).

Results of research examining the link between social media use and mental ill health have however been largely inconsistent, and consensus has not moved far beyond statements that the link is complicated. This has made it very challenging to design evidence-based recommendations and interventions to address the impacts of social media across society, policy and industry (e.g., the Online Safety Bill).

My fellowship will address this issue by delivering a ground-breaking portfolio of basic and applied research. My team will take a novel mechanistic approach, investigating the mechanisms underlying the impact of social media on adolescent mental health (e.g., Mechanisms A and B, among others). We will first study these mechanisms of interest using observational data across three distinct levels of scientific explanation (experiential, algorithmic, and biological/cognitive). We will then systematically manipulate them in a longitudinal study, to test their mental health impact on an individual level. This will allow us to select two targets that will be developed and deployed in Years 5-7 of the fellowship in both policy and as an intervention that allows adolescents to experiment with changing their own social media use to improve their mental health.

This research will be complemented by an agile pipeline of co-investigation and knowledge exchange with policymakers and stakeholders to address current questions in policy and practice, to ensure this investment is continuously creating positive impact for young people throughout the fellowship. This will be supported by an internship scheme that recruits talented undergraduate students from backgrounds underrepresented in academic research to assist my team and policy partners on select summer project 'sprints'. In depth co-creation with young people and parents will further tailor research outputs and dissemination throughout the fellowship.

The evidence provided by my fellowship will therefore feed into crucial national decisions about childhood and digitalisation that will shape the lives of our children today and adults tomorrow, for decades to come.