For many parents and educators, the sight of a teenager scrolling through social media for hours has become a familiar and worrying backdrop to modern adolescence. A new study co-led by University of Alberta researchers suggests that worry is well placed. The study found that spending more time on social media is linked to higher levels of anxiety and depression among Canadian teenagers—and that girls appear to be affected most. Using data from the COMPASS school-based research project, the team analyzed responses from more than 58,000 adolescents aged 12 to 18 during the 2021-22 school year and nearly 45,000 during the 2022-23 school year. In addition, they followed roughly 27,000 of the same youth from one year to the next, allowing them to observe whether changes in social media habits were accompanied by changes in mental health. The sample included boys, girls, and transgender and gender-diverse youth, a group often left out of large-scale studies and one that has been shown in previous research to experience disproportionately high rates of depression, self-harm and suicide. Co-author Dr. Valerie Carson, a professor in the Faculty of Kinesiology, Sport, and Recreation at the University of Alberta, said the study’s design was critical. “It’s important to provide evidence on the topic in the same group of adolescents over time, including transgender and gender-diverse youths, to better understand how these associations change or develop and if certain demographic groups are at greater risk,” she said. Carson also noted that past research has documented a steeper rise in depression among girls than boys, and that transgender and gender-diverse youth face serious mental health disparities. The new study, she said, helps clarify the role that social media may be playing in those trends.
The research drew on data from COMPASS, a large-scale project that collects health and behaviour information from schools across British Columbia, Alberta, Ontario, Prince Edward Island and Quebec. For the new study, researchers examined how much time teenagers spent scrolling through social media each day and whether that amount increased, decreased or stayed the same over a year. They measured participants’ levels of anxiety, depression and overall well-being, as well as how well the teenagers managed their emotions and how they got along with others in their lives. By combining large cross-sectional samples with a longitudinal group that was tracked over two school years, the study was able to offer a more detailed picture than a single one-time survey. Instead of simply asking whether heavy social media use and poor mental health occur together, the researchers could ask whether an increase in social media use is followed by a decline in mental health. That kind of evidence is especially valuable for informing policy, because it points toward cause-and-effect relationships rather than mere correlations. The inclusion of transgender and gender-diverse youth is also significant, since much of the existing research on adolescent social media use has focused on cisgender boys and girls. The study’s authors emphasized that young people’s experiences of social media are not uniform, and that a more complete understanding requires looking at different groups and different patterns of use over time.
The study’s central findings are stark. The results showed that just one additional hour of daily social media use was linked to a 15 per cent higher chance of experiencing moderate to severe depression. The same extra hour was also associated with a 12 to 13 per cent higher likelihood of moderate to severe anxiety. These percentages may sound modest at first, but they become significant when considered against how many teenagers use social media every day. Madelyn Curle, who led the study as part of her PhD work, noted that “these percentages are meaningful considering how many youth currently use social media on a daily basis.” In practical terms, a teenager who spends three hours a day on social media is facing substantially greater odds of mental health struggles than one who spends two hours a day, and those increased odds accumulate across a population of millions of young people. The negative effects were not limited to depression and anxiety. Higher levels of social media use were also tied to lower levels of overall well-being, poorer emotional control, and a noticeable drop in the quality of personal relationships. That finding is particularly important because it suggests that social media may be eroding some of the very connections and coping skills that help protect teenagers during a vulnerable stage of development.
Although the negative associations were present across the full sample, the study found that girls were affected most. Past research has pointed to several possible reasons for this difference, according to Madelyn Curle. “There is evidence that girls may use social media more intensively than boys. Additionally, social media use may have a larger influence on girls’ body image, which may lead to mental health concerns such as depression,” she said. This may help explain why girls have experienced a steeper increase in depression in recent years compared with boys. However, the study also delivered an important caution: when researchers looked at changes over time, they found that increases in social media use from one year to the next predicted poorer mental health in all adolescents, with no gender differences observed. In other words, boys and gender-diverse youth were not immune. The harm is not limited to girls, even if girls are showing the most immediate and visible effects. The findings suggest that the overall pressure of social media on adolescent development is broad, and that different groups may be affected through different mechanisms. For girls, body image and intensive use may play a bigger role; for others, the effects may be slower or more subtle, but they are still present. The study’s inclusive sample allowed the researchers to see these patterns more clearly than earlier work that excluded gender-diverse participants.
The implications for policy are direct. According to the researchers, the findings appear to support the case for newly introduced Canadian legislation known as the Safe Social Media Act, which proposes restricting social media use by youths under 16. “Our findings suggest that decreasing social media use over time may support better mental health outcomes among adolescents, so introduction of the act may be one way to reduce that usage,” Carson said. Because the study showed that reductions in use were associated with better mental health, policies that limit access or encourage healthier digital habits could make a real difference. However, the researchers also warned that any policy needs to be thoughtful and carefully designed. Carson noted that future studies will need to look at which apps teenagers are using and whether they are using them actively or passively—for example, whether they are posting and interacting with friends or simply scrolling through curated images and videos. Those distinctions matter, because not all social media experiences are equally harmful. Madelyn Curle added that young people themselves need to be included in discussions about regulation. “There may be some benefits to social media, including connection, identity development and social support for LGBTQIA+ teens, so they need to be engaged in discussions to ensure that while policies reduce potential harms of social media, they are also equitable,” she said. This is a crucial point: for some marginalized young people, social media can be a lifeline to community and support that they cannot access in their daily lives. A blanket approach to restriction could inadvertently cut off those benefits.
The study was funded by the Canadian Institutes of Health Research, Health Canada, the Ministère de la Santé et des Services sociaux of the province of Québec, and the Direction régionale de santé publique du CIUSSS de la Capitale-Nationale. Valerie Carson is also a member of the Women and Children’s Health Research Institute, adding further weight to the study’s connection to broader child and adolescent health research. Taken together, the findings strengthen the growing consensus that social media is not a neutral force in the lives of young Canadians. It can provide connection and community, but it also carries measurable risks for anxiety, depression and well-being. The study’s authors are careful not to argue that all social media use is bad; rather, they argue that the amount of time spent on these platforms matters, that increases in use are particularly concerning, and that some groups—especially girls—are more vulnerable than others. For parents, educators and policy-makers, the message is clear: reducing social media use, particularly for teenagers who spend many hours a day on these platforms, could help protect adolescent mental health. At the same time, any response must be guided by evidence, informed by young people themselves, and balanced against the real benefits that social media can offer. The study adds an important, large-scale Canadian perspective to a debate that too often relies on anecdote and alarm. It shows that the issue is not just about willpower or parenting; it is a public health challenge that requires attention, research and careful policy at the highest levels.