A new study of nearly 1,200 adolescents provides robust evidence that spending two or more hours per day on social media significantly increases the risk of depressive symptoms and lower well-being twelve months later. The effect is strongest in early adolescence, particularly among girls aged 12–13.
The Research
The study, published in the Medical Journal of Australia and led by Murdoch Children’s Research Institute (MCRI) and Deakin University, tracked participants from ages 9 to 19 as part of the Child to Adult Transition Study (CATS) in Melbourne. Researchers collected annual data on social media use and mental health outcomes, including depression, anxiety, well-being, and self-harm. They found that adolescents who averaged two or more hours of daily social media use showed noticeable increases in depressive symptoms and declines in well-being one year later, compared to those who used social media less than one hour per day. The peak vulnerability occurred during early adolescence (ages 12–13), with girls in this age group showing the highest risk.
Dr. Nandi Vijayakumar of MCRI emphasized that while the individual effect size is modest, the population-wide impact is substantial because nearly all adolescents are exposed. The data provide a baseline for Australia’s world-first social media age restrictions implemented in December 2025.
Why It Matters
For teens and parents, this study clarifies that not all screen time is equal: the dose (two hours a day) and developmental stage (early adolescence) are critical. The adolescent brain undergoes rapid changes in social sensitivity and reward processing, making it more vulnerable to the negative effects of social comparison, cyberbullying, and harmful content. Understanding this window can help families set healthier boundaries.
What You Can Do
- Set limits: Encourage less than two hours of recreational social media per day, especially for younger teens.
- Promote digital literacy: Discuss online risks and healthy habits, such as curating feeds and taking breaks.
- Monitor mood: Watch for changes in sleep, mood, or social withdrawal that may accompany heavy use.
Source: Neuroscience News
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