Deputy Prime Minister Nick Clegg is pledging to improve the standards of mental health treatment and "bring mental health out of the shadows".
In a speech launching the Government's new Mental Health Action Plan, which sets out 25 areas where immediate action is called for to improve care, support and treatment, Mr Clegg will say: "All too often, attitudes to mental health are outdated; stuck in the dark ages; full of stigma and stereotypes.
"It's time for us to bring mental health out of the shadows and to give people with mental health conditions the support they need and deserve."
Things need to change so that sufferers are no longer confronted with outdated attitudes, full of stigma and stereotypes and treatment that is unhelpful and damaging, Mr Clegg will say.
Mr Clegg argues that waiting times for common mental health services are still too long, particularly in certain areas of the country. There have been stories of people of all ages being transferred, sometimes hundreds of miles, to access a bed, he says.
He will tell a conference of mental health experts, charities and users of mental health services that some children with severe mental health problems are still being cared for in adult wards, and that face-down restraint is still being used - despite clear evidence of how damaging it can be.
He will speak as a Time to Talk campaign was launched nationwide to help people talk openly about mental health and get support. February 6 has also been picked as the first-ever Time to Talk Day.
The campaign is led by the Time to Change programme, run by charities Mind and Rethink Mental Illness, with the aim of ending the stigma and discrimination faced by people with mental health problems.
People working in the media and entertainment industry are asked to help put an end to sensationalist stories, inaccurate reporting and negative stereotypes which promote stigma. They should give people with mental health problems the chance to tell their stories, while employers will be urged to work to build on the good practice. It is hoped they will understand that the mental well-being of their staff is central to their success as a company, according to Mr Clegg.
One in three (34%) of sufferers said they come up against stigma and discrimination on a monthly or weekly basis, according to Time to Change figures from a survey of almost 5,000 people with mental health problems. Having to deal with stigma and discrimination from friends and in their social life had been a problem for 61% of people.
Mr Clegg notes that mental illness costs the economy £105 billion every year. He adds that life expectancy for a man with severe mental illness is reduced by 20 years compared to the rest of the population and 15 years for a woman.
Mr Clegg says: "We're working hard to ensure that the needs of those with mental health problems are considered not just in the NHS, but also across our public sector: with better support in education, employment, the justice sector, housing and elsewhere.
"Ultimately, it's going to take all of us working together to achieve the change in attitudes to mental health that we need."
People with mental health conditions will have the same legal right as those with physical conditions to choose where they go for care, including being able to choose the person and provider from April.
Mr Clegg is to tell the conference that the choice will not be limited to an NHS organisation, and that patients will also be able to choose from a voluntary or independent provider offering services on the NHS when they go to see their GP to seek help.
New standards on access and waiting times for mental health services are also to be introduced next year, so that patients will know what kind of treatment to expect and when.
The Government is also rolling out the Friends and Family Test to mental health services for the first time, used in all mental healthcare settings by the end of this year.
Stephen Dalton, chief executive of the NHS Confederation's Mental Health Network, said: "For far too long there has been plenty of talk about putting mental health on a par with physical health, but so far this talk hasn't turned into reality. As an example, just last month plans were announced which would see mental health services subject to disproportionate reduction compared with our acute counterparts - I'm afraid this demonstrates the system's institutional bias and lack of true commitment to parity.
"Today's plan has real potential, but it won't live up to this potential if as a society, we don't put our money where our mouths are and make sure we make progress in mental health much further and much faster."
Geraldine Strathdee, NHS England's national clinical director for mental health, said: "It is really good news that the deputy prime minister is helping to put the spotlight on mental health. It doesn't always get the attention it deserves in all sorts of ways, including in the media.
"This is why NHS England is implementing a wide ranging programme to achieve parity of esteem for people with mental ill health. Our priority areas for improvement include access to psychological therapies, support for people with dementia, and access to care in a crisis.
"The programme aims to prevent and detect long-term physical and mental health conditions much earlier. And we will have a particular focus on those with the most serious mental health conditions such as psychosis."