Cuts in mental health services for children in England amount to a national crisis with tragic consequences, a charity has said.
More than half of councils have cut or frozen budgets for child and adolescent mental health, according to official figures obtained by Young Minds.
Experts believe early care is better for patients and value for money.
But budget reductions meant tough decisions were necessary, according to the Local Government Association.
Provision of mental health services for young people varies widely across England, with entry-level care largely funded by local authorities, which are trying to slash spending.
Research has found young people who do not receive help in the early stages of their illness can suffer serious consequences, often needing time in hospital or remaining ill during adulthood.
Young Minds submitted a Freedom of Information request about funding of child and adolescent mental health services for 2014-15 and the previous four financial years.
It had responses from 99 out of the 151 councils it contacted.
More than half had made cuts over the last five years, while nine councils had kept funding at the same level.
The biggest reduction was at Birmingham City Council, from just above £2.3m in 2010-11 to £125,000 in 2014-15, a drop of 94%.
A spokesman for the authority said government funding had ended in 2010 and after a public consultation, it was decided to stop paying for a service that was primarily an "NHS responsibility".
The council preferred to "prioritise those services for which it was responsible" at a time when significant savings were required.
"We are very much committed to ensuring that children and young people in Birmingham have access to the mental health services that they need," the spokesman added, adding other services were provided for vulnerable children by the council, the NHS and the voluntary sector.
However, some local authorities have increased spending, such as Worcestershire County Council, where the budget went from £678,523 in 2010/11 to £4.9m for 2014/15.
Overall the figures were "deeply distressing", said Sarah Brennan, chief executive of Young Minds.
"Children and young people's mental health services have been chronically underfunded for decades.
"The latest round of cuts will add to the devastation of local services and compound the struggles of young children and their families."
Ministers continue to stress their commitment make young people's mental healthcare as good as their physical healthcare.
"The government has legislated for it," said care minister Norman Lamb. "We now have to get every area of the country to do what is clearly the right thing.
"There is no justification for disadvantaging mental health as against physical health."
Mr Lamb said the government backed the introduction of waiting time for mental health services, to bring them into line with NHS physical health care.
David Simmonds, chairman of the Local Government Association's children and young people's board, said councils had "worked hard" to protect services to vulnerable children but this had become "increasingly challenging" in the current financial climate.
"Local authorities have serious concerns about mental health funding for children, and want a complete overhaul of the fragmented and complex system they currently face each day when trying to access services delivered by the NHS and other partners."
Councils were "committed to change" and were "already playing their part", he stressed.