20 Oct Podcast # 98 – How Exercise Can Help Beat The Symptoms Of Depression
The symptoms of depression can vary from person to person, however strong evidence is mounting that exercise may just be the answer to treating this common mental illness. Not only that, several studies are also finding that our physical activity may even outperform medication designed to treat the symptoms of depression. For years we have all known that diet and exercise can help prevent chronic physical illnesses such as heart disease, obesity and diabetes, but now the focus is on the effects exercise has on our mental health and the results are optimistic.
Depression is a serious problem worldwide
One in six New Zealanders and Australians will experience serious depression at some point in their lives. One in four British adults experience at least one diagnosable mental health problem in any one year and in the U.S one in eight adults have being diagnosed with clinical depression.
Over 121 million people worldwide currently suffer from the symptoms of depression with the war-torn country, Afghanistan reporting the highest prevalence. Overall, women have high rates of depression than men often the risk increasing in the weeks after having a baby.
But it’s not just adults being overcome by the mental illness. Worldwide, it is estimated 1.3 million adolescents died in 2012 with the top three causes of death being road traffic injuries, HIV/AIDS and suicide. For adolescent girls alone, the second-biggest killer after suicide was complications during childbirth.
The statistics on depression are scary and they are not getting any better. Globally, it is responsible for more ‘years lost’ to disability than any other condition including chronic lung disease, diabetes and alcohol related disorders. Switzerland is a country which offers some of the best support in mental health with more than 40 psychiatrists per 100,000 people, however it has a higher rate of depression than the U.S.
A report prepared by the UN agency has suggested that over half the people who develop mental disorders have their first symptoms of depression by the age of 14. It appears better mental health care and knowledge of mental illness seems to not be reducing these stats. In fact, the World Health Organisation estimates that by the year 2020, depression will be the second most common cause of ill health and premature death worldwide.
Could exercise be the best drug in treating the symptoms of depression?
I’m sure you know that going for a run or taking a yoga class can be a great way to alleviate stress after a tough day. We all hear that the rush of endorphins released when we exercise is responsible for lifting our mood and making us feel more positive about life.
But researchers at the Karolinska Institute in Sweden have found that exercise actually detoxes harmful chemicals from our body and in turn can alleviate the symptoms of depression. During exercise, the muscles start to act similarly to the kidneys or liver and produce an enzyme which is essential to purging a molecule linked to causing the brain harm and depression.
Dr Jorge Ruas, principal investigator at the Department of Physiology and Pharmacology stated their “initial research hypothesis was that trained muscle would produce a substance with beneficial effects on the brain”.
What they found during their study was the opposite. “Well-trained muscle produces an enzyme that purges the body of harmful substances. So the muscle’s function is reminiscent of that of the kidney or the liver” says Ruas.
Their results even pointed to the type of exercise which could have the biggest impact on reducing the symptoms of depression, lifting mood and reducing stress. Ruas says cardiovascular exercise was seen to have the strongest effect although “it is possible that other kinds of exercise will also have an effect, like resistance training such as weight lifting. But our results support the use of aerobic exercise like biking and running.”
In the same study, the researchers looked at why those who do not regularly exercise end up feeling sluggish, show signs of depression and are more prone to chronic diseases. “Skeletal muscle appears to have a detoxification effect that, when activated, can protect the brain from mental illness” Ruas says.
It was previously known that the protein called PGC-1α1 increases within the skeletal muscle as the individual exercises, but the reason why was unclear. By observing mice, researchers found that after five weeks of being exposed to a stressful environment of flashing lights and loud noises one group of mice were displaying strong symptoms of depression.
The other group of mice with high levels of the protein appeared to be protected from experiencing mental illness. This is thought to be due to the protein producing an enzyme called KAT, which is responsible for converting the harmful kynurenine molecule into kynurenic acid. This is a harmless substance that can be easily passed out of the body.
Exercise vs medication in beating depression
Exercise has been long recommended as a therapy for treating mild symptoms of depression or as an adjunct therapy for those on anti-depressive medication. But could it be just as effective as prescribed medication?
Neuroscientist at Duke University, James Blumenthal, specialises in depression and published a very interesting study in the Journal of Biobehavioral Medicine. In this study Blumenthal split a group 156 adults who had mild or moderate cases of depression into three.
One group was prescribed the antidepressant drug, sertraline. The second group was prescribed sertraline and given an exercise regime three times a week for 45 minutes. This regime consisted of a 10 minute warm up, 30 minutes of jogging or walking at a pace that would keep their heart rate at 80 to 90 percent of their maximum and then a 5 minute cool down to finish.
Group three were only given the exercise regime above as treatment for their symptoms of depression.
The results were surprising. Over the 16 week period, the participants were supervised by the researchers and professional staff. They found that all three treatments delivered equal results. Treating the participants with exercise alone was just as effective as treating those with sertraline, yet the risks weren’t as high. Sertraline has been linked to a wide range of concerning side effects, including major depressive disorder, obsessive–compulsive disorder, and social and panic anxiety.
The long-term impact was where the results were really profound. After 16 weeks of treatment 83 percent of the participants were considered to be in remission and free from any symptoms of depression. When the study had concluded, participants were able to continue with the treatment received or try something new. Researchers followed up with the patients six months later and found…
38 percent of the participants on prescribed medication relapsed into depression.
31 percent of the participants who exercised and took medication relapsed into depression.
Just 8 percent of the participants who only exercised relapsed into depression.
Blumenthal described the differences between exercise and medication in this statement. “One of the positive psychological benefits of systematic exercise is the development of a sense of personal mastery and positive self–regard, which we believe is likely to play some role in the depression–reducing effects of exercise.”
Regular exercise should be the focus rather than intensity or duration in treating depression
A review published in the Journal of Clinical Psychiatry looked into the benefits of exercise for the clinically depressed. Researchers of the Division of Psychiatry at Boston University School of Medicine found positive association with exercise in alleviating the symptoms of depression.
It was suggested that it is likely a “combination of biological, psychological, and sociological factors influence the relationship between exercise and depression”. This is consistent with the view on current treatments for depression involving pharmacotherapy and psychotherapy.
While we regularly focus on the intensity when we train, the research interestingly suggests this focus can be overwhelming to someone who is depressed. Current recommendations for most countries is that adults exercise at least 30 minutes a day at moderate-vigorous intensity. Based on the findings from this review, those who are experiencing depression are better of exercising for 20 minutes a day, three times a week at a moderate intensity. According to the researchers, this is significant enough to reduce the symptoms of depression.
What I also found interesting was that while depression may be an additional risk factor for exercise noncompliance, it was reported drop-out rates among depressed patients were not too different from those in the general population who were not suffering a mental illness.
Unhealthy lifestyle driving an increase in chronic diseases and mental illness globally
The evidence is there in front of us that an unhealthy lifestyle is driving an increase in the burden of chronic diseases and mental illnesses like depression worldwide. Research suggests that by just including an hour of walking per week into your life can reduce your risk of developing depression by 50 percent.
Promoting physical health within the communities vulnerable to developing depression is a valuable mental health care strategy. But let’s be honest. Statistics suggest we are all vulnerable of experiencing the symptoms of depression at some point in our lives. While there is growing acceptance that the mind-body connection is very real, I think we tend to forget how powerful maintaining good physical health can be at reducing our risk of suffering from a mental illness.
While some studies suggest aerobic exercise is the best therapy for those depressed, there is plenty of evidence to suggest any form of exercise that gets your heart rate up and blood pumping is beneficial. The best advice is to find an exercise routine you enjoy and can partake in consistently. Practice yoga, meditation or go for a swim if high intensity exercise is not for you. Run, box or cycle if you like to sweat it out a bit more.
Whatever it is, a healthy lifestyle is one of the simplest ways to treat the symptoms of mild to seasonal depression and maintain good mental health. If you think you are suffering from depression, it’s time to speak to someone. Follow the advice of your physician, but it might be worth your while to ask about trying natural lifestyle changes before or instead of anti-depressant medication.