Exercise as it relates to Disease/Childhood Activity for lifelong mental health

The following is a critical analysis of the journal article “Lower levels of physical activity in childhood associated with adult depression” by F.N. Jacka et al (2011) as published in the Journal of Science and Medicine in Sport.

What is the background to this research?

The health benefits of partaking in even modest amounts of physical activity have been widely known for many years. Through an improved energy balance an enhanced body composition is achieved as well as changes in glucose levels, lipid profiles, blood pressure and inflammation among many others. From these improvements comes a reduced risk of developing cardiovascular disease, diabetes, respiratory diseases and several forms of cancer. The links between physical activity and improved health have been shown in both adults and children and as such many governments now produce guidelines surrounding physical activity goals such as that produced by the Department of Health’

As well as having short term health benefits children who are physically active have been shown to be more active later in life further increasing the health benefits.

In addition to physical health, physical activity has also been shown to have great benefits to mental health. In studies involving both adults and children evidence has suggested that increased physical activity may lead to reduced depressive symptoms in the short term. As such this may have prevent the onset of depression as well as provide relief for those experiencing symptoms.

However despite this research little is know of the long term protective effects of physical activity on depression. This study looks to fill this gap of knowledge and potentially reduce the growing burden of mental health on society.

Where is the research from?

‘Dr Felice Jacka’ led her team of highly experienced,Victoria based researchers in this study. The authors specialise in a range of fields including. mental health, public health and epidemiology.Although several authors had received funding for research the providers had no role in designing, conducting or analysing this study. The ethics for this study were approved by Barwon Health.

As this study used data from the larger Geelong Osteoporosis Study (GOS) participants were male and female between 20–96 and located within the Barwon Statistical Division.

What kind of research was this?

As a part of larger epidemiology research this cross sectional study looked specifically at the link between childhood physical and adult depression.

As this was a cross sectional study information was able to be assessed across a wide range of society with little cost to researcher or disruption to participants. However as this is simply an insight into the correlations at a particular point in time causation and other influencing factors are not assessable and therefore further research is needed to fully understand the mechanism of the relationship.

Additionally as the surveys in most cross sectional studies (including this research) are self reported by participants some elements of social desirability bias may be present. Also as the data collected is often historical in nature societal viewpoint and education may shift altering the potential data collected.

What did the research involve?

The research conducted in this study was collected as a part of the larger GOS involving initially women and extending to men of all adult ages in the Barwon District of Victoria. Among other surveys in the study participants completed questionnaires on physical activity(PA) and depression according to the following schedule.

Questionnaires completed in this research

Questionnaire	Women	Men
Physical Activity	1994-1997	2003-2006
Depression	2000-2001	2003-2006

As no new or original data was collected for this study this could be seen as an entry level approach to this field of research. When seen as such the methodology was well approached as it was cheap, non invasive and provided information on a wide range of Australian society. However as the questionnaires used retrospective self reporting many results may be inaccurate due to memory faults and social desirability bias. Additionally, reporting on depression was conducted using DSM-IV self reporting rather than clinical diagnosis, which would have given a more accurate result.

What were the basic results?

Through careful analysis of reported childhood physical activity levels and self reported incidences of depression the authors found some common patterns. Both men and women in this study who reported low levels of physical activity in childhood were 35% more likely to report depression in adulthood. This finding supports the theory that childhood physical activity has impacts on lifelong mental health as well as physical.

Although the findings of this study show some support to their hypothesis the authors point that due to the study type requiring retrospective self reporting the study is clearly limited. Additionally they note that while physical activity may have some effect on mental health later in life there are many other factors not accounted for in this study which may be of influence including genetic predisposition and personality types. The authors suggest further research in this area using more alternate, more controlled research methods.

What conclusions can we take from this research?

Despite the previously noted limitations of this study involving self reporting and childhood recall a moderate link can be seen between childhood activity and adult mental health, in particular depression. As noted by the authors a more detailed study is required to fully understand this effect. Little research has been published in this area due to the long time period required for full results.

The 2014 study by McKercher and colleagues goes some way to assess the links between the maintenance of childhood activity into adulthood and depressive symptoms, finding a that reduced activity increased prevalence of depression in men. This study reduced recall bias by using a previous data set and following up with this population group later in life.

Practical advice

Although not entirely conclusive in its links between childhood physical activity and adult depression this study was not suggesting children need to participant in extraordinary levels of activity for future protection. It is currently advised that children aged 5-17 aim for at least 60 minutes of moderate to vigorous activity daily. This is known to benefit the child’s physical health, current mental health, cognitive abilities as well as aid them socially.

Habits made in childhood, especially surrounding activity have life long effects and this study show yet another reason why meeting these guidelines is so important.

Further information/resources

If you or someone you know is struggling with depression or other aspects of mental health the following offer information and services dedicated to helping those in need;

‘Beyond Blue’

‘Black Dog Institute’

‘Lifeline’

For ideas to get yourself and those around you active see the ‘Find Your 30’ by SportAus