Screens are changing young brains. Canada needs a plan

By Emma Duerden, Franco Vaccarino, and Alison Palmer

Dr. Emma Duerden is an associate professor and Canada Research Chair in neuroscience and learning disorders – applied psychology at Western University. Dr. Franco Vaccarino is professor emeritus at the University of Guelph and former president and vice chancellor. Alison Palmer is the evaluation and special projects lead at Brain Canada Foundation. 

When it comes to online harms, Canada is at a crossroads. When Parliament resumed this fall under Prime Minister Mark Carney, we expected swift action on the Online Harms Bill (Bill C-63) and an opportunity to advance the conversation around how we can protect children’s health and well-being in an increasingly digital world.

Instead, it continues to be unclear whether the Carney government intends to move the bill forward and Canada still lacks a co-ordinated strategy to address the developmental, cognitive and mental health risks of excessive screen use.

Since the 1990s, Canada’s online harms response has developed only incrementally, with few updates. Meanwhile, digital environments have evolved rapidly, reshaping childhood and adolescence. Infants now swipe before they speak. Teens can spend 12 hours a day online. AI-enhanced platforms and opaque algorithms influence how children play, communicate, and learn — often in ways parents and policymakers don’t fully understand.

Excessive screen time in early childhood is linked to developmental delays, especially for language and social interaction. For older children and teens, daily screen use beyond two hours is associated with anxiety, depression, and reduced self-esteem. Longitudinal studies connect social media use with increased impulsivity, aggression, self-harm and eating disorder symptoms.

Brain imaging studies reveal that screen time can affect how young brains grow and function. In young children, heavy use is associated with changes in areas tied to language, vision and higher-order thinking. For teens, frequent social media use can alter how the brain responds to rewards and feedback, activating circuits similar to those involved in addiction. While more research is needed, these findings suggest screen use is shaping brain development — and may affect behaviour and mental health over time.

Longitudinal studies connect social media use with increased impulsivity, aggression, self-harm and eating disorder symptoms.” – Emma Duerden, Franco Vaccarino, and Alison Palmer

Some argue the evidence is only correlational. But when it comes to children, even small effects demand serious attention. The developing brain is sensitive to environmental input. Our policy choices today will shape a generation’s mental health, academic success, and future well-being.

We’ve seen this before. It took decades for tobacco, substance use and childhood obesity to be addressed as public health priorities. Waiting for absolute certainty on screen-related harms risks repeating those costly mistakes.

What’s needed is a smarter, evidence-based approach: age-appropriate guidance, stronger regulation, better education, and a commitment to equity. That requires national leadership and co-ordination.

The Quebec Special Commission on the Impacts of Screens and Social Media on Youth recently issued 56 recommendations — from awareness campaigns to digital literacy in schools and improved monitoring. The Canadian Paediatric Society has launched a Centre for Healthy Screen Use, offering practical guidance for families and professionals.

Healthy use is crucial. Digital platforms can offer benefits, especially for youth who are neurodivergent or facing mental health challenges. These spaces offer connection, self-expression, and validation. But those benefits must be balanced with protections.

Other countries are acting. Some jurisdictions have imposed outright bans — like Australia blocking social media access for those under 16. The U.K.’s Children’s Code requires digital products likely to be accessed by youth be designed in “the best interests of the child.” It has reduced targeted advertising and inappropriate content on popular platforms.

Still, many apps rely on manipulative design — notifications, streaks and AI-personalized content — to keep children hooked. Young users are particularly vulnerable due to immature decision-making centres in the brain. As tech becomes more immersive, this manipulation will become more sophisticated.

Frustratingly, independent researchers are blocked from studying these effects, because companies aren’t required to share data or disclose how their algorithms work. That must change.

Canada must move beyond narrow definitions of harm and address the broader digital environment in which children live and grow. Youth must be involved in these conversations.

Key priorities for action include:

• Digital literacy integrated into school curricula
• Public funding for screen-life balance programs
• A regulatory framework modelled on the UK’s Children’s Code
• Long-term investment in research and knowledge mobilization
• Data transparency requirements for tech companies

The goal isn’t to eliminate technology — it’s to create safer digital environments and support families to navigate them wisely. Because right now, we’re letting children’s brains be the testing ground for unregulated innovation.

The time for national action is now. The next generation’s health depends on it.

Note: This op-ed is informed by a recent panel discussion on this topic organized by Brain Canada and hosted by the Canadian Science Policy Centre that included panellists Dr. Emma Duerden, Dr. Patricia Conrod, Dr. Munmun De Choudhury, Dr. Sara Grimes, Dr. Michelle Ponti, and Vidhi Desai, and was moderated by Brain Canada Board Director Dr. Franco Vaccarino.

This op-ed by Emma Duerden, Franco Vaccarino, and Alison Palmer was originally published in the Toronto Star on November 24, 2025.