A study published in the Journal of Adolescent Health revealed a concerning link between sedentary behaviors and the worsening of mental health in adolescents. The research, which analyzed data from over 3,675 British youths aged between 14 and 17, highlights that spending more than three hours daily on sedentary activities — such as playing video games, reading for leisure, or spending long periods in front of screens — significantly increases the risk of psychological distress.

The study was conducted by the Institute of Psychiatry, Psychology, and Neuroscience at King’s College London and utilized information from the Millennium Cohort Study, a longitudinal project that tracks the development of children born between 2000 and 2002 in the UK.

The researchers gathered data at two critical moments in the participants’ adolescence: at age 14 and again at age 17. In the first phase, the youths were asked to complete detailed diaries, recording their activities every ten minutes. These activities were categorized into different contexts, including:

• General physical activities
• Sleep time
• Screen time for leisure
• Leisure without screen use
• Sedentary educational behaviors (such as studying or doing homework)

At age 17, the adolescents responded to a questionnaire based on the Kessler scale, a widely used tool to measure psychological distress. The questionnaire included questions about feelings of nervousness, hopelessness, restlessness, depression, worthlessness, and other related symptoms.

The results revealed that adolescents who spent more than 180 minutes per day on sedentary leisure activities involving screens were at a significantly higher risk of psychological distress by age 17. Video games were highlighted as one of the most impactful activities, with each additional hour of gaming associated with a 3% increase in psychological distress levels.

Surprisingly, the study also found a negative association between excessive leisure reading and mental health — particularly among boys. Youths who read for more than three hours a day reported higher levels of psychological distress. One hypothesis is that excessive reading might lead to social isolation, displacing time that could be spent on in-person interactions or outdoor activities.

On the other hand, the study highlighted a “protective” effect associated with moderate screen use for educational activities. Adolescents who spent between 60 and 119 minutes daily on tasks like homework or virtual classes exhibited lower levels of psychological distress.

The lead author of the study, André de Oliveira Werneck, a doctoral student at the School of Public Health at the University of São Paulo (FSP-USP), emphasized that the methodology used — based on detailed diaries — provided greater accuracy to the data. According to Werneck, many studies use accelerometers to measure sedentary behavior, but these devices do not distinguish between different types of sedentary activities.

“Sedentary behavior is multifaceted. Spending hours attending an online class is very different from playing video games for long periods. Our study was able to capture these nuances, which makes the results more robust and relevant,” said Werneck.

Brendon Stubbs, a professor at King’s College London and co-author of the study, emphasized the importance of considering the context of screen use. “It’s not the screen use itself that’s the problem, but how and why it is being used. Screens used for learning showed benefits, while excessive passive leisure was harmful,” he explained.

The increase in sedentary behavior among adolescents is a growing concern for health authorities worldwide. In addition to physical impacts, such as obesity and cardiovascular diseases, this study underscores the significant role of sedentary behavior in the worsening of mental health issues.

Experts recommend that parents and educators set clear limits on screen time for leisure and encourage in-person, interactive activities. It is also essential to promote a balance between device use for educational purposes and free time dedicated to social and physical activities.

Based on the findings of the study, the researchers suggest several strategies to minimize the negative impacts of sedentary behavior:

• Establish Clear Limits: Limit daily screen time for leisure to less than three hours.
• Encourage Educational Activities: Promote the use of screens for educational and productive purposes.
• Diversify Leisure Activities: Encourage outdoor activities, sports, and social gatherings.
• Personalize Interventions by Gender: Adopt specific approaches, considering that boys and girls exhibit different screen-use patterns.
• Educate About Screen Use: Teach adolescents about the effects of prolonged screen exposure and strategies for managing their time.

The study emphasizes the importance of understanding sedentary behavior in its complexity. It’s not just about reducing sitting time but understanding the context in which these activities occur. Parents, educators, and healthcare professionals have a crucial role in guiding adolescents toward more conscious and balanced screen use, promoting both physical and mental well-being.

In an increasingly digital world, the challenge is to find the right balance between technology, education, leisure, and social interaction, ensuring that adolescents develop healthily in all areas of their lives.