Former prime minister Gordon Brown has claimed there is now "a full-blown mental health emergency" in Scotland.
It comes after the Cottage Family Centre in Kirkcaldy announced it is to hire its own mental health workers.
The Fife charity provides support to vulnerable families and is launching a £100,000 fundraising campaign to help meet demand for counselling staff and a new family therapeutic worker.
The Scottish government said mental health was a "priority".
The Cottage Family Centre is one of Scotland's biggest children's charities.
Mr Brown, who is due to be named as honorary patron of the centre, said the NHS was "facing one of its worst-ever crises".
He said: "NHS crises should have been a thing of the past.
"Of course the Scottish government is free to spend as it sees fit but its decisions mean that far less is being invested in the NHS than the Barnett formula ever intended.
"In effect, it has left the NHS in Scotland hundreds of millions of pounds short of what it should have.
"The crisis in Fife mirrors what is happening across the entire country. There is now a full-blown mental health emergency."
Pauline Buchan, service manager at The Cottage, said: "The new project will provide training and mentoring for an identified group of adolescents whose emotional well-being is causing concern, and who are experiencing difficulty attending and engaging with school and other social situations.
"It is important to recognise the impact mental health can have on the family unit."
NHS Fife is one of five health boards in the country which did not meet the Scottish government's 18-week waiting time standard for child and adolescent mental health treatment in figures published on Tuesday.
The Scottish government said the NHS budget had increased by £3bn in the last ten years and it was committed to a further increase of £2bn by the end of this Parliament.
Minister for Mental Health Maureen Watt added: "Mental health is a priority for this government which is why we are putting in place a ten year strategy. This sets out how we can improve early intervention, have better access to services and better responses in primary care settings.
"We have doubled the number of child and adolescent mental health service psychology posts and are investing an extra £150m in mental health over five years.
"We will also be commissioning a review into rejected child and adolescent mental health service referrals as a foundation for making further improvements."