Small Lifestyle Changes Improve Mental Health in Teenagers

Judging by recent headlines and policy ideas, you might think screen time is the only lifestyle behavior influencing teen well-being.¹⁾Haslett C. Social media and youth mental health defining challenge of our time: Surgeon general. ABC News June 17, 2024 But with young people struggling to deal with mounting mental health issues, it’s crucial we don’t get tunnel vision and instead remember all the lifestyle levers that can play a role.²⁾McGorry P et.al. Mental health of young Australians: dealing with a public health crisis. Medical Journal of Australia. doi: 10.5694/mja2.52047

Our research, published recently, tracked Australian high school students from 71 schools across New South Wales, Queensland and Western Australia. Over time, improvements in sleep, fruit and vegetable intake, and exercise were associated with small but significant improvements in mental health.³⁾Smout, S., Champion, K.E., O’Dean, S. et al. Adolescent Lifestyle Behaviour Modification and Mental Health: Longitudinal Changes in Diet, Physical Activity, Sleep, Screen Time, Smoking, and Alcohol Use and Associations with Psychological Distress. Int J Ment Health Addiction (2024). https://doi.org/10.1007/s11469-024-01350-9

The reverse was also true when it came to unhealthy behaviors like screen time, junk food, alcohol use and tobacco.

A comprehensive look at adolescent lifestyles

Our new study of more than 4,400 Australian high school students looks at a suite of lifestyle behaviors: sleep, moderate-to-vigorous physical activity, sedentary (inactive) recreational screen time, fruit and vegetable intake, consumption of junk food and sugary drinks, alcohol use and smoking.

Firstly, we asked year 7 students (aged 12–13) to report their levels of these lifestyle behaviors and to rate their psychological distress (a general indicator of mental ill-health) using a well-known measurement scale.⁴⁾Prochaska JJ, Sung HY, Max W, Shi Y, Ong M. Validity study of the K6 scale as a measure of moderate mental distress based on mental health treatment need and utilization. Int J Methods Psychiatr Res. 2012 Jun;21(2):88-97. doi: 10.1002/mpr.1349.

Then we examined how changes in each of the lifestyle behaviors between year 7 and year 10 (age 15–16) were linked to psychological distress levels in year 10. Importantly, we accounted for the level of psychological distress participants reported in year 7, as well as their lifestyle behaviors in year 7. This means we can see the average benefits associated with behavior change, no matter where people started out.

Our research showed increases over time in healthy behaviors were associated with lower psychological distress. Conversely, increases in health risk behaviors were associated with higher psychological distress.

How much makes a difference?

On average, when looking at the change between year 7 and 10, every one-hour increase in sleep per night was linked to a 9% reduction in psychological distress.

Each added day of 60 minutes of moderate-to-vigorous physical activity per week was linked to a 3% reduction in psychological distress. Each added daily serve of fruit or vegetables was linked to 4% lower psychological distress.

By contrast, each added hour of screen time was linked to a 2% increase in psychological distress, as was each unit increase in junk food or sugary drinks.

Because drinking alcohol and smoking are less common in early adolescence, we only looked at whether they had or hadn’t drank alcohol or smoked in the past six months. We saw that switching from not drinking in year 7 to drinking in year 10 was associated with a 17% increase in psychological distress. Switching from not smoking to smoking was linked to a 36% increase in psychological distress.

It’s important to note our study can’t definitively say lifestyle behavior change caused the change in distress. The study also can’t account for changes in a student’s circumstances such as in their home life or relationships. With the baseline survey done in 2019 and the year 10 survey done in 2022, there was also the potential impact of COVID.

But our longitudinal design (tracking the same subjects over an extended period) and the way we structured the analysis does help illustrate the relationship over time.

Our study didn’t measure vaping, but evidence shows that, like smoking, it has clear links with adolescent mental health.⁵⁾The impact of vaping on adolescent mental health. Australian Institute of Family Studies. October 2023

What does this mean for teens and parents?

National guidelines for these behaviors set out aspirational targets based on optimum health goals. But movement guidelines⁶⁾Physical activity and exercise guidelines for all Australians. For children and young people (5 to 17 years) Department of Health and dietary guidelines⁷⁾Australian dietary guidelines. eatforhealth.gov.au might seem out of reach for many teens. Indeed, most participants in our study were not meeting guidelines for physical activity, sleep, screen time, and vegetable consumption in year 10.

What our research shows is that a healthy lifestyle change doesn’t have to be all or nothing.

Even relatively small changes – getting an extra hour of sleep each night, eating one extra serve of fruit or vegetables each day, cutting out one hour of screen time, or adding an extra day of moderate-to-vigorous physical activity per week – are linked to improvements in mental health. And stacking changes in multiple areas is likely to stand you in even better stead.

Parents can play a major role in shaping lifestyle behaviors (even into the teenage years!). Expense and time can be barriers, but anything parents can do within their means is a step in the right direction.

For example, modelling healthy social media use,⁸⁾Taddeo C, Spears B. What can you do if you think your teen already has unhealthy social media habits? The Conversation, July 3, 2024 making affordable changes to your grocery shop to improve nutritional content,⁹⁾Burch E, Ball L. Trying to spend less on food? Following the dietary guidelines might save you $160 a fortnight. The Conversation, November 27, 2023 or even introducing set bedtimes.¹⁰⁾Dolan E W. Parent-set bedtimes result in healthier sleep patterns for adolescents, study finds. PsyPost July 26, 2023 And parents can gather information so young people can make positive choices around alcohol, tobacco and other substance use including vaping.¹¹⁾https://positivechoices.org.au/parents/

The bigger picture

Lifestyle changes can support better adolescent mental health, but they’re only one piece of the puzzle. We can’t place the burden of addressing the youth mental health crisis solely on teen lifestyles. There is plenty to be done at a school, community, and policy level to create a society that supports youth mental health.

Young people who are struggling with their mental health may need professional support, which parents and carers can support them to access.¹²⁾Birrell L et.al. I think my teen is depressed. How can I get them help and what are the treatment options? The Conversation, October 4, 2023 Teenagers or young people can also contact ReachOut or Kids Helpline directly for resources and support.

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This article is republished from The Conversation under a Creative Commons license. Read the original article.

Scarlett Smout

Scarlett is a PhD Candidate and Research Associate at The Matilda Centre, University of Sydney.

Katrina Champion

Dr Katrina is a Senior Research Fellow at The Matilda Centre for Research in Mental Health and Substance Use and School of Public Health at the University of Sydney. She is Program Lead of Healthy Lifestyles Research at the Matilda Centre and holds a prestigious Sydney Horizon Fellowship. Dr Champion works at the nexus of disease prevention and mental health, with a focus on the bidirectional relationships between poor mental health and unhealthy lifestyle. She develops, evaluates and disseminates digital interventions to improve both physical and mental health in adolescents.

Lauren Gardner

Lauren is a Senior Research Fellow within the Matilda Centre at the University of Sydney. As Program Lead of School-Based Health Interventions, Lauren has expertise in the development, evaluation, and translation of digital preventive interventions to enhance adolescent health and well-being. The interventions target a range of key health behaviors, including e-cigarette and tobacco cigarette use, alcohol and other drug use, physical activity, diet, sleep, and recreational screen time.