Populating a playground with natural elements that feature sand, grass and water can help reduce signs of depression in children, according to research by the University of British Columbia.

In the six-month study conducted in 2014, 46 children, aged two to five-years-old, were filmed when they went outside to play at two daycare centres in East Vancouver.

Researchers noted that many of the children appeared to be at a loss filling their free time in the playgrounds, both of which had largely concrete play areas and lacked green features.

"I've never seen this amount of boredom or dazed looks," Susan Herrington, a landscape architecture professor with UBC, said in a video released by the university.

Herrington notes that many daycares may be unable to afford expensive renovations of their outdoor play areas, so the study focused on observing the effects of adding affordable alternatives.

Researchers installed water, bamboo, sand and ornamental grass features, then waited two weeks before returning to observe the children at play.

Based on the children's filmed reactions and interactions with peers, researchers compared the before and after behavior using two standardized questionnaires to assess their changes in mood.

"Depressive symptoms like looking sad or not smiling much went down after the modifications. The videos showed kids much more engaged in play and engaged in positive ways with each other," said co-researcher Mariana Brussoni, an associate professor in UBC’s school of population and public health and pediatrics, and a scientist at B.C. Children’s Hospital, in a release.

"After the redesign, they were much more energetic and creative, exploring their environment, touching things, inventing games and interacting with their peers a lot more," Herrington said.

In mid-March, Delta - a municipality in Metro Vancouver - voted to add more natural elements to future playgrounds to encourage children to take risks.

Their decision followed neighbours Richmond, B.C. where a million-dollar playground was built in 2014, incorporating more natural features that added risk into children's play. Richmond is now looking to renovate more of their parks, too.