Exercise as it relates to Disease/Physical activities impact on depression

/Physical Activities Impact on Depression/

This is a review of the article Relationship Between Physical Activity and Depression and Anxiety Symptoms; A population study conducted by De Mello MT, Lemos VdA, Antunes HKM, Bittencourt L, Santos-Silva R, Tufik S

What is the Background to this research
Depression is a highly prevalent disease with every 1 in 16 Australian experiencing symptoms every year. Symptoms of depression vary from person to person and is often associated with anxiety. Symptoms are commonly characterised by sadness and depressed feelings for 2 weeks or more along with lack of sleep, lack of motivation, changes in weight, elevated drinking and/or drug abuse etc. Mental health, in particular, depression and anxiety is among the most prevalent chronic diseases effecting our society. Benefits of physical activity (PA) for the human body and psychological well-being has been heavily researched and well documented. There has been increasing evidence from studies suggesting physical inactivity negatively impacts our moods. Many studies have been conducted to investigate the impact of regular PA on the mood and symptoms of depressive and anxiety disorders, concluding that performing regular moderate intensity aerobic exercise has improved both mood and symptoms. Moreover, research has shown that those suffering from depression and anxiety are commonly more physically inactive with those that do not have depression and anxiety. However, regardless of this evidence many people do not partake in regular PA and prefer to live a more sedentary lifestyle. Additionally, prior to this study, very few had explored the association between PA practice and mood within a particular population sample. This aspect that has been lacking in other studies has been thought to reduce adherence to and acceptance of exercise propositions.

Where is the Research From
This study was conducted in Sao Paulo, Brazil between July and December 2007 and published in the Journal of Affective Disorders in July 2013. The cohort included 1042 male and female volunteers aged 41.9±14.4. The present study determined the most common symptoms of depression and anxiety in a population and their association with regularity of PA.

What kind of research was this
A cross sectional study design was performed involving a large sample size of 1042 volunteers inclusive of males and females. There were 3 stages to acquire participants. First stage consisted of selecting 96 districts from 4 regions of 1500 districts. Participants were required to complete questionnaires administered by trained psychologists. Questionnaires included; Brazilian version of the beck depression inventory (BDI), assessing anxiety levels rated on a Likert scale from 0-63; Self-report regular PA requiring the participant to answer two questions on the performance and frequency of PA; Brazil’s Economic Classification Criterion (BECC) which evaluates economic status of the participant via the quality of durable consumer goods that the family owns, number of rooms and bathrooms, and number of domestic employees on a monthly wage in the house, groups were categorised into upper, middle and lower. The research method made it difficult to estimate PA level due to subjectivity from self-reported questionnaires and decreased ability to determine associations of cause and effect from results. However, detection of relationships between regular PA and symptoms of depression and anxiety.

What were the basic results
Results from the present study depict an inverse relationship between PA and depression or anxiety symptoms. This supports the general idea that not practicing regular PA increases likelihood of experiencing depression and anxiety in comparison to those that partake in regular PA. Within Sao Paulo alone 63.2% claimed to not practice regular PA. Main results are as follows; 24.4% of the sample participated in regular PA equal to or greater than three times a week and 12.4% declared to complete two or less sessions of PA during the week. PA has been found to positively impact mental health in adults and elderly. Improvements have been associated with social, behavioural, psychological and physiological aspects. Hypotheses include enhanced serotonin release due to distribution alterations to its precursor, Tryptophan, common in aerobic exercise, and reduced imbalances in hypothalamic-pituitary-adrenal axis, postulated due to its ability to reduce the stress response. Interestingly, brain-derived neurotrophic factor has been identified as a major influence due to its role in neuroplasticity, neural transmission, neural modulation, cell proliferation and neurogenesis.

Predominant predictors of anxiety were lower socioeconomic status, obesity, lack of physical activity, specific age groups and being deemed overweight. An inverse correlation was found between age and anxiety; 35-49 year old are 12.3 times, 50-64 are 3.2 times and 65 years or older are 2.2 times more likely to exhibit symptoms. Attributed to the reduced responsiveness and psychological maturity common in older adults. Furthermore, the probability of anxiety was 1.5 times higher in non-physically active than regularly active volunteers.

Additionally, lower and middle socioeconomic classes displayed a higher prevalence of volunteers not participating in PA, revealing 7.3 and 4.1 higher prevalence of depression. Of the upper class, 28.8% did not practice regular PA. Volunteers with nine years of education indicated a higher prevalence of PA, 60.5%, while less than nine years of education with non-regular activity was lower at 39.5%. Interestingly, non-physically active women, lower socioeconomic groups and less education displayed a higher prevalence of depressive symptoms. Analysis of results showed a 1.4 times higher likelihood of depression for those that do not practice PA when compared to volunteers that are active for three days or more a week.

What conclusions can we take from this research
Conclusions we can draw from this study are PA has a positive association with mood, anxiety, depression and holistic well-being and this has been a general belief for years. Exercise has been described to induce an anxiolytic and anti-depressive state in healthy populations. Furthermore, overweight and obese individuals exhibit a greater chance to experience symptoms of anxiety, considered to be the cause of their lower levels of PA in comparison to eutrophic people. Volunteers of 65 years or older were less PA but did not show more anxiety, hypothesised to be a result of reduced responses to emotional stressors and psychological immunisation common with older adults. Additionally, lower and middle socioeconomic classes displayed a heightened likelihood for depression and anxiety symptoms to escalate.

Practical Advice
PA is a practical and effective way to improve symptoms of anxiety or depression for all. General guidelines indicate participants in 150 to 300 minutes (2.5–5 hours) of moderate intensity PA per week will improve health and lifestyle. Additionally, based on results from this study and others, moderate intensity aerobic exercise three days or more a week would promote the greatest health improvements. To increase adherence, ensure the form of exercise you are undertaking is enjoyable for you. Furthermore, exercise should not be used as the sole treatment for anxiety or depression due to the complexity of mental health and the need for further research.

Further Information and Resources
Further studies supported the notion of PA improving depression and anxiety by concluding that habitual PA reduced subsequent risk of developing depressive and anxiety disorders.

Below are website resources to support those interested to learn more or experiencing anxiety and depression:


 * Beyond Blue Depression and Anxiety Checklist
 * Black Dog Institute - Depression
 * Black Dog Institute - Anxiety
 * Beyond Blue - Supporting someone with Depression or Anxiety
 * Beyond Blue - Depression Facts
 * WHO Depression Facts
 * Australian Government Physical Activity Guidelines