Replacing sedentary behaviour with a certain amount of physical activity each day can reduce your depression risk by 26%.
As you roll out of bed, wipe the 6am sleep out your eyes and pop in your earbuds, you’re probably not thinking about the mental health benefits of listening to gangsta rap while jogging slowly on a treadmill. However, a new study published in JAMA Psychiatry has just provided the “strongest evidence” yet that exercise prevents depression.
Better yet: revealed in the study is the exact amount of exercise that could help you reduce the likelihood of developing depression.
Harnessing the genetic data of 300,000 patients, researchers at the Massachusetts General Hospital found that people who did more exercise had a lower chance of experiencing a major depressive disorder. While this has been studied for years, it’s never been established whether ‘not exercising’ is a symptom or cause of depression.
However, lead researcher, Karmel Choi, says the significance of this new study is that it shows exercise has a causal effect on one’s mental well being: “We found evidence that higher levels of physical activity may causally reduce risk for depression.”
Specifically, the research demonstrates that replacing sedentary behaviour with 15 minutes of “moderate to vigorous” activity each day can reduce your depression risk by approximately 26%.
“On average, doing more physical activity appears to protect against developing depression … and any activity appears to be better than none.”
Promisingly, and as pointed out by the ABC, “While the study showed physical activity could prevent depression, it found no evidence that being diagnosed with depression affected a person’s ability to exercise.”
That said, depressed individuals are still at an increased risk of reduced physical activity, Joseph Firth (a senior research fellow at Western Sydney University, who was not involved in the study), told the ABC.
“It’s still the case that people with depression are less active than the general population, but [the study] is saying it’s not necessarily the depression itself that’s driving that relationship,” Dr Firth said.
“It could be social factors, rather than the actual genetics of depression… So, it’s still worth thinking about physical activity interventions for people with depression.”
Dr Firth added that this latest study has provided “the strongest evidence” yet for using exercise to prevent depression, telling the ABC, “These findings could ultimately inform new public health schemes, which use physical activity and exercise to not only reduce the risk of physical health problems, but also to combat the mental health epidemic.”
However, if you don’t want to wait for a public scheme to get your butt moving, you are always welcome to try replacing 15 minutes of your daily sedentary behaviour with “moderate to vigorous” activity, which the study found could reduce your depression risk by about 26%.
On that note: as always when scientists come up with a new finding (or suggestion) made ever more suggestive by media hype, one should assess it with a level head. In this study, for instance, although 15 minutes was found to be an effective “mood booster” for 300,000 research volunteers, one must remember that it was a random number, chosen by scientists, that happened to work for the bulk of the group.
But when it comes to applying this scientific development to your own life, you need to consider if you are already doing more (or less) exercise than the average citizen, as well as any other personal circumstances you may have. For that reason, when it comes to improving your mood, or—for that matter—anything related to your mental health, you should always consult a doctor (and perhaps also in this case, a PT) before making any changes (or attempting to ‘treat’ or diagnose yourself).
As Dr Choi points out: “More work needs to be done to figure out how best to tailor recommendations to different kinds of people with different risk profiles.” To that end she and her team are looking at, “Whether and how much physical activity can benefit different at-risk groups, such as people who are genetically vulnerable to depression or those going through stressful situations.”
“(We) hope to develop a better understanding of physical activity to promote resilience to depression.”
In other words: don’t go pulling out the Nobel Prize just yet. But good news is good news, so watch this space…