A study led by ANU has challenged a common perception that homosexual and bisexual people are at risk of poor mental health and suicide.
Lead researcher Dr Richard Burns from ANU said homosexual or bisexual orientation was not a major risk for long-term mental health problems.
"Childhood sexual trauma, risky health behaviours, smoking, a lack of positive support and negative social interactions pose more of a risk for people's mental health than their sexual orientation," said Dr Burns from the ANU Centre for Research on Ageing, Health and Wellbeing.
He said homosexual and bisexual people were more likely to experience these mental health risk factors than heterosexual people.
The findings come as Australia's Parliament wrestles with whether same-sex marriage should be legalised.
The study followed about 5,000 adults over eight years as part of the Personality and Total Health Through Life Project.
"Initially, we found there was a long-term risk for depression and anxiety among individuals with a bisexual orientation, and there was long-term risk for anxiety amongst homosexual individuals. But when we adjusted for these other mental health risk factors, we found no major risk associated with sexual orientation itself," Dr Burns said.
"We concluded that all things being equal that there is no particular mental health risk for people with a homosexual or bisexual orientation.
"Our findings emphasise the importance of using longitudinal data to estimate long-term mental health risk associated with sexual orientation."
The study results are published in Epidemiology and Psychiatric Sciences.