CANBERRA - Mental disorders such as depression and schizophrenia are the leading cause of disability among young people around the world, Australian researchers said on Tuesday.

Researchers from the Melbourne-based Murdoch Childrens Research Institute worked with the World Health Organisation to analyse the "disease burden" carried by young people.

Using international data to calculate, scientists first of all ranked various health conditions. They then multiplied that figure by the number of years a person was likely to live with the disability. The researchers also considered years lost due to the disease in their study.

According to the study paper's co-author Professor George Patton, the figures, which considered millions of global participants, revealed 45 percent of the burden among 10 to 24-year-olds could be attributed to mental disorders.

In particular, depression, schizophrenia, self-harm, alcohol misuse and bipolar disorder ranked among the top 10 disability burdens.

In high-income countries, like Australia, mental illness accounted for two-thirds of the age group's disease burden.

"That's largely because we have been very successful in dealing with other causes of disease burden (like HIV and tuberculosis)," Prof Patton told Australia Associated Press on Tuesday.

"(Locally) the disease burden is driven by conditions causing disability rather than death."

Also contributing to the disease burden of 10 to 24-year-olds in Australia were unintentional injuries (12 percent) and infectious diseases (10 percent).

He noted that the burden of disease increased steadily with age.

Meanwhile, Professor Patton said the study, the first to analyse the global causes of disability in adolescence, could be used to identify risk factors for disease later in life.

"Although the lifestyles that young people adopt might not have an immediate effect on their health, they have substantial effects later in life," he said.

"Interventions to address health risk behaviours and unhealthy lifestyles are likely to be more effective in these years than in adulthood when patterns are established."