A new study at the Alberta Children's Hospital is putting a piece of age-old advice to the test to see whether exercise can really boost mood — and change the brains of teens suffering from depression.

The program is a partnership between the Calgary YMCA and researchers at the hospital and will put 16- to 18-year-olds through a standard exercise regimen for 12 weeks. Then researchers will study MRI test results from the teens to see whether the exercise is sparking change in the hippocampus.

"We've seen problems in the structure and chemistry of the hippocampus in people with depression," said Frank MacMaster, chair in pediatric mental health at the Alberta Children's Hospital Research Institute for Child and Maternal Health.

"Exercise ... has been shown to actually have a positive effect on hippocampal brain plasticity. That means with exercise, we potentially have a way to try and rebuild that part of the brain."

Depression affects roughly one in seven Canadians — or around 12 per cent, according to the Public Health Agency of Canada.

MacMaster says that number is slightly higher in young people, hovering around 15 per cent.

In teens, depression tends to manifest itself in social withdrawal, academic struggles, loss of enjoyment in previously pleasurable activities and a prevailing feeling of depressed mood, guilt and sadness.

In extreme or untreated cases, it can lead to suicide.

Untreated, costs can be 'profound'

For young people, their teenage years are formative to who they will become and that's why MacMaster says it's crucial to recognize it early and ensure help is accessible.

"The costs are profound by not intervening," he said. "All the things that you really build on in adulthood to make your life happen really start during these years so if you're derailed by a depressive disorder during this time, you can think of the impact."

The study will focus on having teens do aerobic activity to hopefully regrow and return function to their hippocampi.

"Physical activity is important for life-long health and particularly, as we know, with brain plasticity," said Shannon Doram, vice president of health and wellness at the YMCA. "We wanted to convey to people that there is actually a very strong correlation between activities done in childhood and early adolescene and life-long health."

It's hoped aerobic activity will increase the ability of the body to process oxygen, which is what researchers think will spark the cascade of regrowth and reconnection within the hippocampus.

While past research has supported the idea of exercise boosting mood, this study will be the first time its effects on the hippocampus will be measured.

If it proves successful, MacMaster says the potential for helping young people with depression is enormous.

"You could be anywhere in the world and follow the protocol," he said. "This has the potential to spread quite wide."