Exercise as it relates to Disease/The association between physical activity and depression in adolescents

The following Wiki page is a critical analysis of the research paper Physical activity and depression in adolescents: cross-sectional findings from the ALSPAC cohort.

What is the background to this research?
Depression is a serious, very common illness negatively impacting a person's feelings, thoughts, and actions. The onset of depression generally occurs throughout a person's adolescent years, with youth suicide the leading cause of death for people aged 15-24 years.

Many research studies have found that there is a general association between increased physical activity and reduced depressive symptoms among adolescents, but few have examined the intensity of PA rather than a focus on total PA.

This study was undertaken to determine if there were associations between depressive symptoms in adolescents (aged 14 years) and objective measures of physical activity (both total time of PA and time spent in moderate-vigorous activities).

Where is the research from?
The research was conducted with a large group of adolescents, aged 14 years, based in the United Kingdom. The authors of this research are each professors at the University of Bristol.

The study was financed by the UK Medical Research Council, the Wellcome Trust, and the University of Bristol. It is unlikely that this created bias within the research study as these groups were not involved in the writing of the report nor did they gain anything form it.

What kind of research was this?
The research was a cross-sectional study. A cross-sectional study obtains data from one specific point in time and are often carried out to investigate associations between risk factors and the outcome of interest [4] – more specifically for this research, the association between physical activity and depression/depressive symptoms in adolescents. These types of studies are beneficial as they are less expensive and easy to conduct for a large cohort, but on the other hand only provide data for a single moment in time, meaning results could differ if a study was completed in a different timeframe.

The research used a self-report questionnaire, requiring participants to have the ability to recall their mood and feelings each day for the previous two weeks, which can impact the study’s validity and reliability. [1]

What did the research involve?
2,951 adolescents who were participating in the Avon Longitudinal Study of Parents and Children (ALSPAC) were used. For the purpose of this study, a self-report Mood and Feelings Questionnaire (MFQ) was used to determine depressive symptoms and an accelerometer was worn by each participant to measure levels of physical activity.

A self-report questionnaire limits the ability to acquire accurate and reliable data, children can become overwhelmed trying to recall their mood over the past 14 days and forget to include key details.

This study may also be limited by the use of accelerometers. While they have proven their validity for movements such as walking and running, they do not accurately measure physical activity for movements on elliptical trainers or bicycles.

What were the basic results?

 * In terms of depressive symptoms, the median score on the MFQ was a 4. Girls scored higher than boys with a median score of 4 and 3 respectively.


 * On average, participants engaged in 21 minutes of moderate-vigorous physical activity each day. Male participants were active for an average of 25 minutes per day, which was higher than female participants who were only physically active for an average of 17 minutes per day.
 * Adolescents who had higher daily average levels of physical activity had reduced odds of depression.

What conclusions can we take from this research?
The conclusions drawn by the authors of the research was that there was an association between the total amount of physical activity and depressive symptoms among adolescents, but time spent in moderate-vigorous PA was not. They inferred boys were more physically active than girls, and that they showed fewer depressive symptoms.

I agree that there are signs of a relationship between higher levels of physical activity and fewer depressive symptoms. However, I don’t believe the design of the study is able to provide sufficient evidence to suggest boys are always more active than girls and therefore show fewer depressive symptoms.

Results for this study aligned with other similar research, both conducted before and after this study was published. There was a general consensus that increased amounts in physical activity would reduce the number of depressive symptoms experienced among adolescents.

Practical Advice
Becoming more physically active will help to improve your mental health and decrease the likelihood of developing depressive symptoms. Whilst there is no benchmark level of physical activity set to achieve this, adolescents should be aiming for at least 60 minutes of moderate to vigorous intensity exercise each day, as recommended by the World Health Organisation (WHO).

Unsure of what types of exercise you should be doing or lacking motivation? Talk to an exercise physiologist or other qualified exercise professional to help develop a program suitable to your needs. This will help build motivation and build your support network.

As a parent with concerns for your child's well-being, seek out professional advice by consulting with a general practicioner, psychologist, or other medically qualified professional.

Further Information/Resources
The following resources are for those interested in looking at other research related to physical activity and its relationship with depression:


 * https://www.webmd.com/depression/guide/exercise-depression
 * https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/depression-and-exercise

For those who are after more information or support, the following links can assist you or a loved one who may be suffering from depression:


 * https://kidshelpline.com.au
 * https://www.beyondblue.org.au
 * https://headspace.org.au
 * https://www.blackdoginstitute.org.au