Does Physical Activity Reduce Major Depression?

This report focuses on physical exercise and nutrition as important lifestyle interventions in reducing the symptoms of depression among adult Australians aged 20 to 65 years. The report includes a systematic literature review, data interpretation, and key findings.

Running head: DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
Does physical activity reduces major depression
Name of the Student
Name of the University
Author note

1DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
Table of Contents
Abstract............................................................................................................................................2
Introduction and rationale................................................................................................................2
Methodology....................................................................................................................................3
Current knowledge deduced from literature review........................................................................5
Data interpretation...........................................................................................................................8
Key findings...................................................................................................................................11
Conclusion.....................................................................................................................................12
References......................................................................................................................................13

2DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
Abstract
Depression is one of the major depressive disorders that are affecting millions of people
worldwide. In Australia, about 300 million people are affected annually and hence contributing
to the burden of disease. Due to sedentary lifestyle (SB) and unhealthy living, people are
gradually being exposed to increased risk of depression that is affecting their functional ability to
perform activities of daily living. Until recently, it has been found that lifestyle modifications are
beneficial in improving mood and preventing future depression. Therefore, the following report
focuses on physical exercise and nutrition as important lifestyle interventions in reducing the
symptoms of depression among adult Australians aged 20 to 65 years.
Introduction and rationale
Depression is a clinical mental health condition that greatly affects the functional ability
of a person. Globally, around 300 million people suffer from depression being the leading cause
of worldwide disability and major contributor to the burden of disease across the globe (Jorm &
Reavley, 2012). Several types of depression prevail ranging from mild to severe as outlined by
World Health Organization (WHO). It can be estimated that about 6% of adult Australians suffer
from major depressive illness (Reavley et al., 2011). Major depression greatly affects adult
Australians that are characterized by loss of pleasure, unhappy mood and feelings of
dissatisfaction and tiredness causing physical and emotional problems. Effective approaches to
prevention of depression are required in reducing major depressive symptoms and in improving
health outcomes. According to Harvey et al., (2017) physical activity strategies can be helpful in
reducing major depression symptoms in depression prevalent countries like Australia and
therefore, I have chosen the research topic of how physical activity programs can be helpful in
reducing the major depressive symptoms among the adults Australians aged 20 to 65 years.

3DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
Methodology
For aligning the research question with the outcomes of the proposed research, it is
important to conduct a systematic literature review on the research topic. Relevant evidence need
to be deduced from the vast pool of available research that needs to be analysed comprehensively
while carrying out systematic review. Systematic literature reviews is aimed at identification,
evaluation and summarization of major study findings that can be applied into practice (Khan et
al., 2011). Moreover, summarization of main findings is helpful in identifying the literature gaps,
as it is the main aim of these literature reviews. Therefore, in the present research, literature
review helped in understanding the relationship between physical exercise activities and major
depression reduction among the adult Australians aged 20 to 65 years.
The electronic databases like PsycINFO, Pub Med, Science Direct, Public Health, Ovid
Medline Elsevier BV and Cochrane Library was used to get access to wide range of scientific
literature relevant to the research topic. These databases provide full-text journal articles that are
reliable, authentic and peer-reviewed. Journal articles relevant to the research topic were include
for the systematic literature review after the conduction of detailed database search.
One of the vital elements of a systematic literature review is appropriate use of keywords
or search terms like most commonly terms or short phrases that can be helpful in retrieving
journal articles by entering in the databases. The key search terms used for the present review are
major depression, depression, depression interventions, burden of depression and physical
activity interventions that reduces depression in Australia. Boolean operators are also important
elements in a literature review as these are logical terms that need to be added with the search
terms for an authentic and appropriate search. These operations help to provide productive
results by using the terms AND and OR and applied for the databases.

4DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
Selection process depends on the meticulous selection of journal articles that need to be
included in the study. Inclusion and exclusion studies are guided by selection criteria set before
the research. Those papers that comprises of longitudinal, cross-sectional and randomized
control trails studies were included in the study published from 2008 to 2018 published only in
English. Moreover, the target population that comprises of participants of age 18 to 90 years was
also included. The abstract of journal articles were reviewed to make sure that the studies
selected were relevant to the research question or topic of interest.
The studies that were published before 2008 and apart from English were excluded from
the study along with papers that were not peer-reviewed. Moreover, the search key terms that did
not match with the research topic were also excluded from the study.
A critical thematic analysis was carried out for the studies for drawing the important
information from the journal articles. The papers were studied considering the aim,
methodology, results, limitations and literature gaps along with implications for future research.
Finally, the data was analyzed by going through the content of the articles and assessing the
quality, research efforts, inflicting thoughts presented in the papers as literature reviews should
focus on the debates that literature ahs undertaken. This helps to provide an insight into the
available literature and its relevance to the research question.
Current knowledge deduced from literature review
In the current literature review, the studies were analysed by dividing them into themes
like use of physical activity interventions in treating major depression for managing this
condition in Australia as well as globally.
Recent research has shown that physical exercise has both physical and psychological
benefits and helps in improving the mood and reducing anxiety. Regular exercise helps to ease

5DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
the depressive symptoms and as a result, provide coping mechanism in dealing negative thoughts
in a healthy way (Carek, Laibstain & Carek, 2011). Initially, treatment for depression included
anti-depressant medication and counselling as outlined by psychologists, therapists and
psychotherapists. However, from the literature review, it is highlighted that individuals who
perform regular physical exercise and workouts tend to show fewer signs of depression as
compared to those who do not perform physical activity. According to a study conducted by
(Josefsson, Lindwall & Archer, (2014) physical exercise for minimum 30 minutes can be
beneficial in reducing the symptoms of major depression and have reduced risk of developing
this mental disorder condition. Happiness inducing workouts like yoga, running, dancing, hiking
and strength training helps in relieving depression and anxiety. Exercise increases the blood flow
to brain by releasing endorphins that are natural antidepressant that significantly relieve
symptoms of major depression in the individuals. Exercise greatly relieves stress, promotes
sleep, improves memory, boosts mood and as a result, improves the overall functioning of an
individual in performing daily activities (Asmundson et al., 2013).
The above fact is illustrated in the first theme: physical activity interventions for
depression where this intervention can be beneficial in preventing and treating major depression.
Consistent physical activity has shown successful results as antidepressant medication in
managing symptoms of depression among elderly population (Mammen & Faulkner, 2013).
Moreover, it enhances social interaction among the depressive individuals and as a result, there
are reduced feelings of isolation and loneliness. Physical exercise has shown to prevent
depression irrespective of gender, age and exercise intensity. Exercise is considered one of the
behavioural approaches that complement pharmacotherapy by relieving depressive symptoms
and enhancing the overall well-being of an individual. Aerobic exercises like brisk walking or

6DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
jogging, anaerobic exercise comprising of relaxation, strength and flexibility training helps to
prevent the symptoms of depression in majority of individuals (Déry et al., 2013). Therefore,
from the first theme, it is evident that although antidepressant effect of physical exercise remains
debatable, efficacy of exercise in reducing depressive symptoms is well established.
The second theme is the nutrition and physical exercise intervention for depression
management in Australia. Along with physical exercise, healthy nutrition is also needed for
improving mood and alleviating signs of depression. Healthy diet alone cannot reduce the
symptoms of depression and require fitness regimen to prevent future depression. The important
food items like selenium, vitamin D, omega-3 fatty acids, antioxidants, vitamin B, zinc and
protein containing foods greatly help in reducing the symptoms of depression (Kuczmarski et al.,
2010). Selenium levels in the body are directly linked to mood as low levels contribute to poor
mood. Similarly, vitamin D deficiency is also witnessed in mood disorders and therefore, this
vitamin is helpful in fighting depression. According to Bloch & Hannestad, (2012) populations
that do not consume omega-3 fatty acids are tend to have high depressive disorders. These fatty
acids increases the availability of healthy fats to the brain, protect nerve cells and myelin sheath
preservation and as a result, there is proper brain functioning reducing the risk of depression and
mood disorders. Antioxidants help in preventing cell damage by making a destructive effect
against the free radicals and as a result, protect the brain (Maes et al., 2012).
Apart from nutrition, physical exercise also contribute to alleviation of mood disorders
like depression as it imparts psychological, physical and social wellness irrespective of gender
and age. Australian adults who undertook physical exercise and healthy nutrition programs for
depression showed significant results in reducing its symptoms and in preventing adverse
depressive episodes (Jacka et al., 2010). In other words, it can be stated that physical exercise

7DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
improves mental health of Australians adults experiencing major depression. The literature
review suggests that healthy diet needs to be included in the fitness regimen so that mental
disorders like depression can be prevented. Diet imparts emotional well-being mentioned in
nutritional psychiatry where a dietary pattern that comprises of high intake of vegetables, fruits,
whole grain, olive, fish and antioxidants can be helpful in decreasing risk of mood disorders like
depression. This fact can be supported by the study conducted by Jacka et al., (2010) where
physical activity programs and nutrition included in treatment regimen were found to be
powerful against alleviating depressive symptoms.
The third theme suggested that sedentary lifestyle increases the risk of mood disorders
like depression and physical exercise helps to curb this risk and future depression. A study
conducted by Hidaka, (2012) stated that adults who are physically active experience less
depressive thoughts than individuals who do not perform physical exercise. Sedentary
behaviours include too much sitting that is detrimentally linked to various disease progressions
like diabetes, cardiovascular disease and premature mortality (Pasco et al., 2011). Depression is
associated with sedentary behaviour and moderate-to-vigorous exercise helps to reduce the
depression symptoms encouraging individuals to perform physical exercise (Helgadóttir, Forsell
& Ekblom, 2015). A study conducted by Hallgren et al., (2016) showed that exercise-related
mechanisms help to alter NE, 5-HT and BDNF, reduce pro-inflammatory cytokine levels and
increase proliferation of hippocampus cells. These pro-inflammatory processes indirectly or
directly affect depression development influencing 5-HT system and adiposity interactions. High
levels of adiposity functions both consequence and as precursor of depression that reflects
bidirectional relationship driven by inflammation (Lackland & Voeks, 2014). This fact supports
the third theme suggesting that sedentary behaviour greatly contribute to depressive thoughts.

8DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
KYN/TRP ratio depicts changes in both brain and peripheral blood that was found to be high
among obese or overweight adults as compared to people who are not indulged in active living
(Herring, O’connor & Dishman, 2010). Sedentary lifestyle is associated with depression as
inflammatory markers contribute to increased adiposity via interactions with 5-HT system
(Helgadóttir, Forsell & Ekblom, 2015). The third theme highlights the fact that adiposity and
inflammatory markers contribute to depression witnessed in sedentary behaviour and therefore,
physical exercise has antidepressant effects that can be helpful in alleviating symptoms of
depression.
Data interpretation
From the above current knowledge gained from literature review, it is clear that
physically active individuals tend to experience less depressive thoughts as compared to
physically inactive counterparts.
Sedentary behaviour
One of the key issues that arise from the literature review is sedentary behaviour
contribution to depression prevalence. According to a study conducted by Schuch et al., (2017)
sedentary behaviour (SB) and physical inactiveness is seen in individuals with major depressive
disorders. SB increases the risk for cardiovascular diseases, obesity and diabetes that imparts
depressive thoughts in the individuals due to lifestyle restrictions leading to social exclusion and
loneliness. According to Australian Institute of Health and Welfare, 2010 14% of adult
Australians suffer from mental illness with 15% of children of the age 16-24 years as compared
to 27 million people affected globally (World Health Organization, 2015). Adults who are
engaged in SB tend to show depressive behaviour and therefore, physical activity interventions
can be helpful in alleviating major depressive symptoms and chances of future depression.

9DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
Another study conducted by (Teychenne, Ball & Salmon, 2010) showed that physical activity,
SB and depression are linked as SB increases of depression. Individuals who are engaged in
leisure-time exercises are less likely to experience depressive thoughts as compared to
individuals who spend hours sitting (Schuch et al., 2017). Individuals engaged in SB are at high
risk of depression and therefore, physical activity promotion can be helpful in imparting better
mental health among individuals with SB.
Physical exercise
Physical exercise interventions are one the best ways to alleviate depression symptoms
and prevent future depression. Exercise is considered beneficial for mood disorders like
depression as these interventions make individuals happy by uplifting their mood. Although,
exercise frequency relation with depression is still unknown, light, moderate and vigorous
exercise influence physical activity behaviour and SB patterns in the individuals. A study
conducted by Aspin et al., (2010), in Australia showed that physical inactivity is a risk factor for
debilitating illnesses where about 70% of Australians suffer from one chronic disease increasing
the burden of disease that in turn impacting the whole healthcare system. When individuals are
engaged in exercise intervention, there is an increase in physical activity and motivation and
gradual decrease in sedentary duration that prevented mood disorders like depressive thoughts in
them (Cooney, Dwan & Mead, 2014). With regular exercise, there is improvement in overall
well-being of an individual that is effective in preventing depressive feelings and treatment of
mild depression, although to a lesser extent. Physical exercise including yoga, meditation and
brisk walking are considered beneficial in terms of cognitive behavioural treatment in reducing
its symptoms in addition to pharmacotherapy (Rimer et al., 2012).

10DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
According to the evidence provided by the literature, it can be deduced that exercise
attainment depends on amount of exercise undertaken. Evidence showed that walking or running
(aerobic exercise), three times for at least 30 minutes and eight weeks is helpful in preventing
depressive thoughts, although more research is required in the future. However, the current
recommendation is exercise for at least 30 minutes of moderate intensity is most effective
preferable for all days of the week (Josefsson, Lindwall & Archer, 2014).
Healthy Diet
According to a research conducted by Deakin University in Australia suggests that there
is powerful influence of food on mood as published in the journal BMC medicine (Jacka et al.,
2015). This groundbreaking finding demonstrates that people suffering from mild to severe
depression should eat healthy diet in order to improve their mood and prevent disorder
complications. Poor diet is considered to a leading risk factor for depression as unhealthy diet
makes one depressed and feels sicker. Unfortunately, only 5% men and 10% women in Australia
eat healthy diet as per Australian Dietary Guidelines suggesting that majority of Australians eat
unhealthy food that is affecting mental health and predisposing factors for chronic illnesses
(Jacka et al., 2010). Healthy diet is viewed as medicine in depression as physical exercise alone
cannot relieve depressive symptoms The research also suggests that cytokines (inflammatory
molecules) produced by body fat may spark inflammation that increases the risk of depression
and causes harm to blood vessels lining (Jacka et al., 2015). On contrary, healthy fats like
omega-3 fatty acids increases the production of neurotrophin proteins that act as manure for the
brain promoting new brain cells growth in the hippocampus suggesting strong correlation
between diet and hippocampus size (O’Neil et al., 2013). Therefore, healthy diet and physical

11DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
exercise interventions implementation among adult Australians can be helpful in reducing
depressive feelings and preventing future depression.
Key findings
Depression is a major public health issue and one of the leading causes of disability
globally including Australia. It has negative health outcomes and decline in functional ability of
individuals affected with major depression in Australia. In extreme cases, it can inflict suicidal
thoughts and ideation in individuals experiencing mood disorders like anxiety and depression.
Various studies showed that SB and unhealthy diet can affect mood and increases the risk of
mood disorders like depression. Therefore, physical exercise and healthy diet can help to
improve mood and prevent depressive thoughts. Physical exercise interventions along with
healthy eating can improve the mental health of the adult Australians experiencing major
depression.
However, many studies in the review showed no relation between physical exercise and
major depression symptom reduction. Studies conducted by Kritz-Silverstein, 2008 and
Birkeland, Torsheim, & Wold, 2009 showed an indirect correlation between leisure-time and
major depression among adults. These studies suggested that anti-depressive effects of physical
exercise remains unclear having implications for future research. Moreover, these findings do not
provide any information regarding intensity and frequency of exercise having protective effect
against depression. These studies do not align with the research question as physical activity
showed no effect on preventing individuals against depression. There were gaps seen in the
literature review, as there was no correlation shown between exercise intensity on treatment and
reduction of major depressive symptoms. Moreover, depression being the second cause of
disability in Australia contribute to burden to disease and has policy implications. The policy

12DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
should emphasize on encouraging physical exercise and healthy eating among adults in Australia
in colleges and workplaces. However, the policy fails in educating and developing understanding
of importance of healthy living to curb major depression. Therefore, the policy is expected to
promote healthy living and encourage individuals to inculcate physical exercise in their daily life
through dissemination of important information.
Conclusion
According to the Australian health statistics, about 45% of people experiences mental
health problems like anxiety and depression once in their lifetime. In a year, about 1 million
adults in Australia suffer from depression and about 2 million experience anxiety disorders.
Depression has become of the leading causes of disability among adult Australians as well as
globally affecting daily functioning of affected individuals. In the past people considered
depression can be treated by pharmacotherapy, however physical exercise and nutrition diet can
be helpful in improving mood conditions and preventing future depression. Recently, in
Australia, people are focusing on lifestyle interventions like physical activity and nutrition for
addressing this issue. However, future studies are required to curb depression by studying
intensity and frequency of physical exercise required along with protective factors that can help
in preventing future depression.

13DOES PHYSICAL ACTIVITY REDUCES MAJOR DEPRESSION
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