UL research shows that even moderate exercise reduces the risk of depression

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New research from the University of Limerick has shown that even moderate daily physical activity can reduce the risk of depression.

A study by physical activity and mental health experts at the University of Limerick and Trinity College Dublin reveals that a dose of physical activity equivalent to just 20 minutes a day (five days a week) of moderate-intensity physical activity , like a brisk walk, was linked with a lower risk of depressive symptoms and likelihood of major depression.

The study, funded by the Irish Health Research Board, has just been published in the journal Jama Network Open.

Depression has significant risk factors for major chronic conditions, including cognitive decline, cardiovascular disease and chronic pain, and increased risk of death and suicide.

It also causes over 5-10% of all disease burden in Europe and the economic cost in the US is estimated at over $210.5 billion. Identifying potentially easy and low-cost health and lifestyle solutions that could reduce the risk of depression remains a top priority.

The lead author however states that there are limits to the conclusions…

Dr. Eamon Laird. a postdoctoral researcher in the Department of Physical Education and Sports Science at UL says, “There is no agreement on how protective physical activity is for depression in general, or how this might vary among adults with illness.

“For this work, we used 10 years of data from the Irish Longitudinal Study On Aging which included information on depression, MVPA (moderate to vigorous physical activity) and other key health-related variables such as disease, lifestyle factors and social -economic status.

«We sought to identify the lowest dose of MVPA associated with protection against major depression and depressive symptoms and the extent to which this varied based on the presence of chronic disease,» added Dr Laird.

The main findings of the study include:

• A dose of physical activity equivalent to 20 minutes a day of MVPA (brisk walking) five days a week was associated with a 16% lower rate of depressive symptoms and a 43% lower chance of major depression
• A dose-response effect was found, such that more MVPA was associated with greater protection for depression;

Notably, doses equivalent to ~30 minutes per day of MVPA were associated with a 7% lower risk of depressive symptoms and 44% lower odds of major depression;

– Doses equivalent to ~60 minutes per day of MVPA have been associated with: 16% lower risk of depressive symptoms and 41% lower odds of major depression;

– Doses equivalent to ~120 minutes per day of MVPA were associated with: 23% fewer at-risk depressive symptoms and 49% less likelihood of major depression

• These results remained significant even after controlling for relevant health-related factors such as biological sex, education, age, smoking and alcohol use, obesity, antidepressant use, and time.
• These results were also materially the same for older adults with and without a chronic disease.

According to Dr. Laird: “This study is highly relevant given the high prevalence of depression in our growing population of older adults. Physical activity in lower doses than the World Health Organization’s recommendations for general health may offer protection against depressive symptoms and major depression – at a minimum, aim to engage in 20 minutes a day of moderate-intensity activity at least five days a week, with greater benefits seen at higher doses.

“Try to fit it into a routine with hobbies or activities you enjoy, and try to do this with others as social interactions, particularly with activity, can also have mental health benefits. Remember that it is a component and that nutrition and a healthy lifestyle will also provide additional benefits beyond physical activity.

Dr. Matthew Herring, senior lecturer and researcher in the Physical Activity Research Center for Health at UL and principal investigator of this HRB-funded research, added: ‘The current findings have significant implications in showing that significant antidepressant benefits appear to be associated with physical activity doses lower than current World Health Organization recommendations for general health, although higher doses were associated with stronger protection.

«Clearly we are not advocating decreased physical activity among the elderly population, but the findings suggest that the greatest improvements in protection against depression among the elderly may be achieved by engaging inactive older adults in physical activity even at doses lower than those recommended for general health .»

I study, «Dose of physical activity and depression in an elderly cohort in the Irish Longitudinal Study of Aging» by Eamon Laird, Charlotte Lund Rasmussen, Rose Anne Kenny and Matthew Herring, has just been released by Jama Network Open and is available here.