More screen time, more stress? Study links device use to teen mental health

By Priyanjana Pramanik, MSc.Reviewed by Lily Ramsey, LLMFeb 19 2025

Research finds higher screen time from childhood leads to more stress and depression in teens, while physical activity helps protect mental well-being.

Study: Childhood Lifestyle Behaviors and Mental Health Symptoms in Adolescence. Image Credit: Iren_Geo/Shutterstock.com

In a recent study published in JAMA Network Open, researchers investigated how lifestyle behaviors in children moving into adolescence can affect symptoms of stress and depression.

Their findings indicate that children who used mobile devices and reported greater screen time were more likely to experience depression and stress during adolescence, highlighting the importance of reducing device usage.

Background

Mental health conditions, which are estimated to affect 25-30% of young adults and adolescents, are a leading cause of disability worldwide. In Finland, anxiety, depression, and other mental health issues are the major sources of sickness allowance for young people.

Identifying risk factors for mental health conditions can help individuals in at-risk groups take action to improve their well-being proactively. For example, adolescents and children who sleep longer have better mental health.

Other modifiable factors include reducing sedentary behavior and increasing physical activity. Studies suggest that adults who engage in some form of exercise regularly can decrease their risk of depression, though similar studies with young adults as participants found mixed results.

However, screen time, particularly time spent on social media platforms, is increasingly recognized as a factor that is seriously associated with mental health challenges.

Researchers have found that using social media is a predictor of higher levels of psychological distress. Reducing screen time and adequate sleep can do more to improve young people’s mental health than an hour a day of exercise.

While most previous studies have focused on individual lifestyle behaviors, few considered the impact that these behaviors jointly can have on mental health in young people. Addressing this research gap can help identify the most important risk factors and, thus, the most effective interventions to promote mental well-being.

About the study

In this study, researchers examined the associations between multiple lifestyle behaviors, including diet quality, sleep, sedentary behavior, and physical activity in Finnish children over eight years old, and mental health symptoms faced by the same individuals in adolescence.

The data was obtained from an eight-year study that followed children into adolescence. Data were collected at baseline, after two years, and at the end of the study.

A physical activity questionnaire was used to collect information on the use of computers and mobile devices, time spent watching television, total screen time, physical activity (supervised, unsupervised, and overall), and participation in sports.

Additionally, participants were given wearable devices with sensors to assess the duration of sleep, sedentary time, and physical activity.

During the eight-year follow-up, the adolescents were asked questions to identify whether they were experiencing symptoms of depression. They also reported on their perceived levels of stress.

The statistical models used to analyze the data adjusted for factors such as sex, age, parental education, percentage of body fat, and pubertal status.  

Findings

Of the 504 children included in the final sample, 51.8% were boys. Of these, 187 adolescents had complete data on their lifestyle behaviors (self-reported) in addition to the mental health assessment. In contrast, 170 had complete data on lifestyle behaviors measured through the wearable device.

On average, the participants reported spending two hours a day on physical exercise, while the device readings showed that 0.7 hours daily were spent in moderate-to-vigorous exercise.

On average, participants spent 4.7 hours a day using screens and slept approximately nine hours each night.

From self-reported data, both supervised exercise and total physical activity were negatively correlated with scores for depressive symptoms and levels of perceived stress. However, individuals who reported higher mobile device use, computer use, and total screen time reported feeling higher levels of stress.

Using mobile devices and spending more time on screens was also linked to experiencing more symptoms of depression.

Notably, after models adjusted for body fat percentage, the association between stress and total physical activity was no longer significant. Further, unsupervised and overall physical activity was linked to lower stress levels for boys but not girls.

From device-collected data, sleep duration, sedentary behavior, and physical exercise were not associated with depressive symptoms or stress. However, light levels of exercise were linked to higher stress levels and depressive symptoms for boys but not girls.

Conclusions

Screen time and use of mobile devices emerged as the most important contributors to poor mental health outcomes, measured by assessing perceived stress levels and depressive symptoms.

Children who used their mobile devices for longer and spent more time on screens were more likely to report depressive symptoms and higher levels of stress as adolescents.

Meanwhile, the lack of a positive association between sedentary behavior and adverse mental health outcomes suggests that the type of sedentary behavior (for example, screen time) matters.

Moreover, a combination of unhealthy behaviors, such as more screen time along with less exercise, may be more detrimental.

Social media use can reduce self-esteem and body image in adolescents while leading to poorer sleep. Screen time guidelines are important to improve the mental health and well-being of children and adolescents by creating safe, balanced digital environments.