Marriage equality advocate Russell Nankervis poses with the rainbow flag during a 'Sea of Hearts' event in support of marriage equality on the front lawn of Parliament House. Credit:Alex Ellinghausen Rather than ask for more funding - which the government would be highly unlikely to provide given it would be an admission that its policy is damaging vulnerable children - the groups have thrown their weight behind the "yes" campaign. The groups, which represent both the frontline and clinical side of mental health, say a "yes" result will "undoubtedly" change thousands of young lives for the better and avert as many as 3000 secondary school suicide attempts each year. This claim draws on peer-reviewed research by some of America's top adolescent mental health experts, published in JAMA Paediatrics, that showed a strong correlation between same-sex marriage policies and high school suicide. The introduction of state same-sex marriage was associated with a 7 per cent relative reduction in suicide attempts. The groups have combined these findings with statistics from the Australian government's own Report on the Second Australian Child and Adolescent Survey of Mental Health and Wellbeing to arrive at the number of 3000. It found one in 40 of all 12 to 17-year-olds reported having attempted suicide in the previous 12 months - about 41,000 people.

Professor Patrick McGorry will be part of the unprecedented mental health group campaign for same-sex marriage. Credit:Rob Gunstone "As Australia's leading youth mental health organisations, we see, hear and feel the real and devastating link between LGBTIQ discrimination and youth suicide rates and mental illness every day," said campaign spokesman Jono Nicholas. "This has only been heightened by the decision to proceed with this postal survey, despite our warnings." Mr Nicholas, CEO of ReachOut, said the campaign was not about politics, ideology or shaming people who vote "no". Rather, it was about highlighting the poor mental health and higher risk of suicide among LGBTIQ Australians. Professor Ian Hickie for the Brain and Mind Centre will also be part of the campaign. Credit:Gary Schafer "We therefore feel collectively compelled to intervene in this debate to ensure Australians have access to real clinical evidence and research, not alternate facts and fiction," he said.

The campaign will focus its attention on voters undecided on whether they will participate in the survey, or vote "yes" or "no". The results of the postal survey will be announced on November 15. Credit:AAP Some of the country's top mental health experts, including former Australian of the Year Professor Patrick McGorry, who heads Orygen, and Professor of Psychiatry Ian Hickie, who leads the Brain and Mind Centre, will participate in the campaign. Many same-sex marriage advocates did not want a public vote – whether by plebiscite or postal survey – partly because of fears about damage to mental health. Some opponents of same-sex marriage have argued against the kinds of mental health concerns raised by the campaign, including Nationals senator Matthew Canavan, who last week said people should stop being "delicate little flowers" and urged them to "grow a spine and grow up".

When Labor raised mental health fears associated with a public vote in October last year, Prime Minister Malcolm Turnbull dismissed them as "completely ridiculous". "Are we going to say that we may not have a public debate on a topic when it is alleged that there will be a minority, some small groups, that will act intemperately?" he said. Few other "no" campaigners have addressed the mental health toll on gay and lesbian Australians. ReachOut says it has never seen as much discussion on a single issue on its online forums. Posters report feeling angry, upset and frustrated by the postal survey, with many asking the question: "Why do you get to vote on my rights?" "I've been seeing so much blatant homophobia and hate, even in places that are usually my safe spaces like specific corners of the internet. I think this is because it's an issue with two sides, and both sides are therefore given voices and opportunities to give their opinions, and so now people think homophobia is okay?" said one young poster.

Loading "It just hurts. It hurts for me, and I'm like the luckiest person with the awesomest support network, so I can't imagine what it must be like for people without that." If you are troubled by this report or experiencing a personal crisis, you can contact Lifeline 13 11 14 or lifeline.org.au, Suicide Call Back Service 1300 659 467, BeyondBlue 1300 224 636, beyondblue.org.au or youthbeyondblue, KidsHelpline 1800 551 800, Q Life 1800 184 527 or qlife.org.au, eheadspace 1800 650 890 or eheadspace.org.au, au.reachout.com