Two brothers have embarked on an ambitious trip around the world to raise funds for research into the devastating illness which claimed the life of their sister.

Heidi Reid lost her battle with depression aged 27, inspiring her brothers to raise funds for research into better diagnosis and treatment of the condition.

Dylan and Lawson Reid will take on a transcontinental motorbike ride from Australia, through Southeast Asia, the Middle East, Europe, down through Africa and across to South America before heading north through the United States into Canada and then across to Japan.

It will be a bitter-sweet journey for the pair, who are still coming to grips with their sister’s death.

Despite the prevalence of depression, the current diagnostic tools are very limited.

Funds raised from the boy’s trip will be donated to the QIMR Berghofer Medical Research Institute where researchers are developing more comprehensive methods for treating people with depression.