Summary: Excess screen time has a negative impact on some aspects of teen mental health, but not others. Experts define excess screen time as spending more than two hours on screens outside of work or school.
Key Points:
Excess screen time is associated with:
- Decreased physical activity
- Sleep loss
- Elevated stress
- Increased depressive symptoms
Screens, Teens, and Mental Health
In the U.S. in 2024, it’s not an exaggeration to say that the youth mental health crisis identified by the Surgeon General in 2020 may be our new normal, which begs a question: does the near universal increase in screen time among children have a negative impact on teen mental health?
It’s an important question. Most of the research on this screen time revolves around social media use, and its impact on teen mental health. We’ve published articles on this topic on our blog:
Does Social Media Harm Teen Mental Health?
Inside the Data: Can Social Media Change the Teen Brain?
However, a new study published recently in the Journal of the American Medical Association (JAMA) called “Childhood Lifestyle Behaviors and Mental Health Symptoms in Adolescence” examines the impact of several different childhood habits, behaviors, and lifestyle patterns on teen mental health – not just screen time.
Here’s how the team of behavioral health scientists framed their research question:
“Are cumulative lifestyle behaviors, including physical activity, sedentary behavior, sleep, and diet quality from childhood to adolescence, associated with perceived stress and depressive symptoms in adolescence?”
To answer the question, the researchers collected data from 187 adolescents recorded between October 2007 and November 2009, with follow-up data collected between December 2015 and December 2017. The data was part of a program called The Physical Activity and Nutrition in Children Study (PANIC). The PANIC study is a long-range research effort that follows a large population sample from pregnancy through adolescence, to determine the impact of physical activity and diet on child and adolescent health.
We’ll share the results in a moment. First, we’ll review the current prevalence rates of depression among teens in the U.S., in order to understand why we need to examine the impact of childhood screen time and activity on adolescent mental health, specifically depression.
Major Depressive Episodes Among Teens
We collected the following data from the 2022 National Survey on Drug Use and Health (2022 NSDUH) and the 2023 National Survey on Drug Use and Health (2023 NSDUH). The NSDUH is a valuable resource that gives us population-level statistics on a wide range of health and mental health statistics. The bullet points below include information from 2022 and 2023, since the 2023 NSDUH didn’t publish data on detailed adolescent age categories, whereas the 2022 NSDUH included that level of detail, reflected below.
MDE, MDE With Severe Impairment, Prevalence Among Adolescents 12-17
- Adolescents 12-17 with MDE, 2023:
- Total: 18.1%
- By detailed age group, 2022:
- 12-13: 13.0%
- 14-15: 21.4%
- 16-17: 23.8%
- Adolescents 12-17 with MDE with severe impairment, 2023:
- Total: 13.5%
- By detailed age group, 2022:
- 12-13: 9.1%
- 14-15: 16.2%
- 16-17: 18.2%
Based on population data published here, that means that in 2023, over 4.5 million teens experienced a major depressive episode, and over 3.3 million teens experienced a major depressive episode with severe impairment.
That’s why we need studies like the one we introduce above. Our teens are in a precarious position, mental health-wise, and we need to learn everything we can related to the circumstance surrounding teen depression, including the impact of childhood screen time – and other childhood behaviors – on overall teen mental health.
Let’s take a look at that study.
Childhood Screen Time, Physical Activity, and Teen Mental Health
The research team explored the impact of the following five behaviors during childhood on stress and depressive symptoms during adolescence:
- Cumulative physical activity (PA): assessed by questionnaire, including:
- Sports participation
- Other supervised physical activity
- Unsupervised physical activity
- PA at different intensities assessed by heart rate monitor, and movement sensor
- Sedentary behavior (SB): assessed by questionnaire, heart rate monitor, and movement sensor
- Screen time: assessed by questionnaire, including:
- Total screen time
- Typical TV time
- Computer use
- Mobile device use
- Sleep: assessed by questionnaire, heart rate monitor, and movement sensor
- Diet quality: assessed by 4-day food records and the Baltic Sea Diet Score
To measure levels of stress and depressive symptoms, participants completed the Cohen Perceived Stress ScaleC (CPSS) and the Beck Depression Inventory (BDI) at baseline, at 2 years after baseline, and at 8 years.
Here’s what they found. These are the screen time and physical activity results, overall:
- Screen time: 4.7 hours per day/average
- TV: 56 mins per day/average
- Computer: 30 minutes per day/average
- Mobile device: 2.25 hours per day/average
- Physical activity: 2 hours per day/average
- Device assisted physical activity: 0.7 hours per day/average
- Sports time per day: 12 minutes per day/average
- Supervised physical activity: 20 minutes per day/average
- Sleep: 9 hours night/average
Here’s how those behaviors impacted mental health during adolescence.
Screen Time: Total, Computer, Mobile
- Higher total screen time associated with:
- Elevated scores on depression assessments
- Elevated scores on stress assessments
- Higher computer use associated with:
- Elevated scores on depression assessments
- Elevated scores on stress assessments
- Higher mobile device time associated with:
- Elevated scores on depression assessments
- Elevated scores on stress assessments
Diet:
- No association with scores on depression assessments
- No association with scores on stress assessments
Physical Activity:
- Total PA time associated with reduced scores on depression assessments
- Total PA time associated with reduced scores on stress assessments
- Supervised PA time associated with reduced scores on depression assessments
- Supervised PA time associated with reduced scores on stress assessments
Sedentary Behavior:
- No association with scores on depression assessments
- No association with scores on stress assessments
Sleep:
- No association with scores on depression assessments
- No association with scores on stress assessments
We’ll discuss these results below.
Childhood Screen Time: A Major Influence on Teen Mental Health
The results of this study surprised us.
Not the screen time results. Those were in line with previous research. But the sleep, diet, and sedentary behaviors results were surprising: they showed no association with depressive symptoms or stress during adolescence. Nevertheless, the impact of screen time and physical activity on mental health – in this study – is clear.
Here’s how the researchers characterize their findings:
“Adolescents who reported higher total and supervised physical activity levels and lower screen time and mobile device use from childhood to adolescence had lower levels of perceived stress and depressive symptoms.”
While research associates poor diet, inadequate sleep, and sedentary behavior with elevated levels of stress and depression in adults, this study found no such association among adolescents, as a result of their childhood behaviors.
What these results do for us, as mental health providers, is heighten our awareness of the impact of overall childhood screen time on adolescent mental health. While we currently allot significant energy toward the role of social media in the lives of teens, we may perhaps be better served – and better able support our teens – by focusing instead on overall screen time and physical activity during childhood. If we create habits that support positive mental health from an early age, we may promote positive mental health during adolescence, young adulthood, and throughout life.
