Research area: Population Health > Centre for Adolescent Health > Adolescent Health

The challenge

Social media has become a central feature of adolescents’ lives. Around 95 percent of adolescents under 18 years old use social media, commonly for around 3 to 4 hours per day. While social media can support social connection, identity exploration, and self-expression, there are several concerns around addictive algorithms, cyberbullying, exposure to harmful content, and other such experiences. The rise of social media over the past two decades has coincided with marked increases in depression, anxiety, eating disorders and suicide among adolescents.

This has led to considerable public concern about whether social media is contributing to declines in youth mental health. However, most of the scientific evidence on adolescent social media use and mental health has relied on observational designs that cannot establish whether social media causes mental health problems or vice versa.

In December 2025, Australia became the first country to introduce federal legislation that aims to restrict adolescents’ access to social media. The Online Safety Amendment (Social Media Minimum Age) Act requires social media platforms (such as Facebook, Instagram, Kick, Reddit, Snapchat, Threads, TikTok, Twitch, X, YouTube) to take reasonable steps to prevent Australians under 16 years old from creating or keeping an account.

This legislation provides a rare opportunity for us to examine how adolescent social media behaviours and mental health change following the implementation of national social media restrictions. As the first country to restrict social media access for under-16s, global regulators (e.g., EU, UK, India) are closely watching its effects to inform their own policy decisions.

Study details

Findings from the Connected Minds study will shape how governments worldwide support youth mental health and digital wellbeing, with direct implications for hundreds of millions of young people worldwide.

The Connected Minds Study collected baseline data from 171 adolescent–parent pairs in the six months before the legislation was implemented. A follow-up wave will be collected six months after implementation (mid-2026), allowing us to track changes over time.

We plan to examine changes in adolescent social media use, including both self-reported and objective measures of time spent on social media apps, the activities and content adolescents engage with, and their motivation for use. We will also examine changes in mental health and wellbeing following the policy implementation, and whether these differ depending on adolescents’ access to social media following the policy implementation (i.e., whether adolescents have actually stopped using age-restricted apps). A sub-study will also examine moment-to-moment associations between social media use and mood in everyday life.

Information for participants

The Connected Minds study recruited 171 adolescents and their parent/guardian in 2025 (before the implementation of the Social Media Minimum Age legislation). A subset of 64 adolescents participated in a two-week mobile phone sub-study.

What does participation involve?

At baseline (2025) and follow-up (2026), adolescents and their parent/guardian are invited to complete online questionnaires about topics including:

• Demographics
• Social media use
• Mental health and wellbeing
• Family and school experience.

Adolescents are invited to take part in an optional two-week mobile phone sub-study involving:

• Installing a research app that objectively collects information about time spent on activities (screentime, sleep, and exercise)
• Completing a few daily surveys about social media use and mood.

Participation is voluntary and data is stored securely. Participants may withdraw from any aspects of the study at any time.

Research leads

Dr Nandi Vijayakumar, Senior Research Office, Adolescent Health

Professor Susan Sawyer, Group Leader, Adolescent Health

Funders and collaborators

This work was supported by The Helen and Michael Gannon Trust, and The Handbury Foundation.

This work is a collaboration between Murdoch Children’s Research Institute and Deakin University.

Publication and research outputs

A study protocol paper has been submitted for publication.

Contact us

For more information about the Connected Minds study, please contact us.

Professor Susan Sawyer & Dr Nandi Vijayakumar
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