As little as 15 minutes a day of brisk walking could help many women who struggle with postpartum depression, a study from a Canadian university says, though some severe cases may still require traditional medical care.

The study from Western University, published Wednesday by the Journal of Women's Health, analyzed data from five research projects involving 242 participants and found that walking resulted in clinically significant reductions in postpartum depression symptoms.

Researchers say the improvements remained even three months after mothers stopped their walking programs.

Led by undergraduate student Veronica Pentland and assistant professor Marc Mitchell from the faculty of health sciences, the study recommends women walk at a "moderate intensity" 90 to 120 minutes per week to reduce symptoms that can include severe mood swings, exhaustion, and a sense of hopelessness.

Mitchell said in an interview that walking offers "psychological distractions," as well as physiological benefits and positive effects on inflammatory markers.

"Aerobic exercises would have similar effects but what's unique about walking is that people perceive it as not exercise, or not good enough," he said. "And yet, it's like the superhero of exercises."

Walking is also fairly accessible for most new mothers, which Mitchell said could be helpful during the COVID-19 pandemic when access to health care has been more limited.

The study says about 23 per cent of new mothers in Canada experience some postpartum depression symptoms, adding that recent studies in Europe and Asia suggest postpartum depression has increased to nearly 30 per cent during the pandemic.

Mitchell said people with major depressive disorders -- which are physician-diagnosed using specific criteria -- might require "more involved medical intervention."

This report by The Canadian Press was first published Oct. 27, 2021.