Ed Miliband’s speech on mental health today is a significant – and good – moment in the campaign to improve understanding and treatment of mental illness in Britain.

It is perhaps particulalry significant that this is his first major policy speech since he launched the theme of One Nation Labour at the party conference a few weeks ago. Because if one of the messages of One Nation is that nobody should be left behind, then clearly there’s a lot of work still to be done to ensure those with mental health problems still get to play a full and fulfilling role in society. Let’s be honest about this – amid the austerity programme, and the cuts, Britain is going backwards on this.

That is why equally significant is the economic focus of Ed’s speech, and the observation that the question is less ‘what is this going to cost?’ than ‘how much are we losing as a country by failing to tackle this?’ So the issue for campaigns like Time to Change, of which I am an ambassador, is not just breaking down the stigma and the taboo and the discrimination, important though that is. It is also about persuading government and business that economically we pay a price in not doing so.

Ed tells the story of a constituent who, at a vulnerable moment in his life, as a relative died and his marriage collapsed, was lured into heroin addiction. The cost to the State since is infinitely larger than the few hours of grief counselling and therapy that might just have kept him from falling into that horrible addiction, and ruining his life for years. Yet still therapy tends to be seen as a luxury add on, not the genuine need it may be. When commentators like Janet Street-Porter describe depression as ‘the latest must have accessory’ you realise how far we still have to go in the fight for decency and proper understanding. Would she say the same about AIDS, or cancer, or a broken neck, or would she say these are ‘proper illnesses’ whereas mental illness is not?

Campaigns like Time to Change, and charities like MIND and Rethink Mental Illness, can help to change attitudes. But even in an era of greater cynicism about politics, do not underestimate the impact of the leader of the Opposition stating so clearly his Party’s commitment to a new approach to mental health. Likewise, Nick Clegg has made clear his strong support for Time to Change and for better services and understanding for mental ill health. The media has a role to play too and some play it well, and were rightly praised in today’s speech. But mental illness is not deemed to be a ‘sexy’ subject and therefore it tends to get relegated down the news agenda. The media today has a responsibility to give proper coverage to the speech Ed Miliband is making, and to launch a proper debate around it.

Change comes when people fight for change to happen. In recent weeks, Sue Baker of Time to Change and I have visited several of our top banks, and have been impressed by their desire to do something about changing attitudes of bosses and staff alike. Ed pointed out how a different approach by British Telecom led to them saving rather than losing money, by investing in proper mental health care for their staff, and by actively fighting discrimination.

If we can adopt that approach not just as individuals or as companies, but as a nation, we will all be better off. Done properly, it will save money, boost productivity, strengthen the UK socially and economically.

When I spoke at the ‘Hear Us’ group of Mental Health users in Croydon last week, I said that I thought we were a decade or two behind the tipping point moments which led to huge attitudinal change in the campaigns for racial equality, women’s equality, gay rights. Hopefully Ed’s speech has accelerated that process. I now look forward to hearing from Jeremy Hunt and David Cameron on the subject.