Mental health reforms being announced by Theresa May today will help tackle the "blackspot" of treatment for children who self-harm and suffer bullying on social media, the health secretary has said.
Jeremy Hunt said three children in every classroom in the country have a mental health condition but only a quarter of them receive help, stressing early intervention can give patients a much better chance of a full cure.
He said measures being announced by the prime minister will also help those with eating disorders or who are "behaving in a strange way" and sometimes have to wait six months for treatment.
Mr Hunt admitted the £1 billion already earmarked for mental health services in February was not yet fully filtering through the system.
But he stressed Mrs May's announcement, which includes extra training for schools, would improve the situation for children.
Under the plans, mental health training for teachers and staff will be rolled out to a third of secondary schools in England next year, with the remaining two-thirds of secondary schools offered the support in the following two years.
Mr Hunt told BBC Radio 4's Today programme: "We've had a slightly patchy start... but overall this year we are seeing the amount clinical commissioning groups spend on mental health is about £1 billion more than it was two years ago, so I think things are going in the right direction."
He went on: "But I think the sort of blackspot is what we do for children and young people.
"Because if we are going to have a society that works for everyone we need to be there.
"And what is more worrying for a parent than if you've got a child with an eating disorder, a child who's self-harming, a child who is behaving in a strange way and as sometimes happens now, people are having to wait for six months to get the help they need, or having to travel to another part of the country."
Mrs May is due to announce:
* Secondary schools will be offered mental health first aid training;
* New trials to strengthen links between schools and local NHS mental health staff;
* A major review of children and adolescent mental health services, led by the Care Quality Commission.
The prime minister will set out the plans as part of her vision of a "shared society", with an increased role for the state in addressing issues of social injustice.
Mrs May will say: "For too long mental illness has been something of a hidden injustice in our country, shrouded in a completely unacceptable stigma and dangerously disregarded as a secondary issue to physical health.
"Yet left unaddressed, it destroys lives, it separates people from each other and deepens the divisions within our society.
"Changing this goes right to the heart of our humanity; to the heart of the kind of country we are, the values we share, the attitudes we hold and our determination to come together and support each other."
The focus on schools is driven by figures showing over half of mental health problems start by the age of 14 and 75 per cent by 18.
Russell Hobby, general secretary of school leaders’ union NAHT, said: "Just as we are becoming more aware of children's mental health issues the resources are being taken away. School budgets are being cut by £3bn so it will become increasingly difficult to fund in-school care for children unless these cuts are reversed immediately.
“This problem is exacerbated when the school seeks to access help itself, because of the chaos in the health and social care system.”
Joint research between NAHT and mental health charity Place2Be has revealed that seven out of 10 school leaders found that funding was the main barrier to putting in place professional mental health support for pupils. Six out of 10 cited the lack of services or qualified professionals locally as a significant barrier.
Mr Hobby added: "Schools have always been on the front line with children's mental health because school is often where issues first become apparent and a school is often a parent's first port of call if they are looking for support.
Sir Ian Cheshire, chairman of the Heads Together campaign, an alliance of charities and businesses interested in mental health, said: "The prime minister’s announcements today are extremely important and very welcome, as they show both a willingness to tackle the broad challenge of mental health support and a practical grasp of how to start making a real difference.
But Liberal Democrat former health minister Norman Lamb said Mrs May was reannouncing policies agreed under the coalition government.
"This is a puny response to a burning injustice and an attempt to cover up for this government's failure to deliver on promised investment for children's mental health," he said.
"Measures to improve mental health care in schools were already agreed during coalition, and the current government has failed to ensure the investment needed to implement them has got through.
"Much of the additional £1.4 billion of funding secured for child mental health care is being diverted to prop up other services. This amounts to theft of money intended to improve the lives of vulnerable young people."
It comes as a survey by the Prince’s Trust charity, released today, found that almost half of all young people experience so many emotional problems at school that they are unable to focus on their studies.