Mike Doig, president of the Headteachers' Association of Scotland, said at the launch of new guidelines on counselling which are being sent to every Scottish school: "The vast majority of teachers are not well-equipped to meet the needs of pupils who experience emotional and social problems.
"Counselling in education is a professional specialism, and putting more funds into staffing and teaching resources, while helpful in many respects, does not place the necessary experience and expertise in front of pupils with the problems."
But Mr Doig, who was lending headteachers' support, warned that there was a growing dilemma for schools which were under increasing pressure to raise performance targets. This "inevitably diminishes their capacity to support and counsel pupils".
He also called for an overhaul of personal and social education in schools so that social and emotional problems can be dealt with, at a time when young people are under more pressure than ever before and when guidance provision may take some time to recover from the management restructuring of secondary schools.
Early intervention to stop children's problems spiralling out of control was a key factor, Mr Doig said. "If I were to add up the hours spent by an assistant head and a guidance teacher on just one of our regular customers who presents a behaviour problem, and cost their time, we would probably conclude that we simply could not afford the child."
Anne Houston, director of Childline Scotland, said it is clear from callers to its helpline and at the conferences it runs for young people that "the one thing they say they want is a counselling service in school. That is significant because it points to a demand for a service that is seen as independent."
Pupils attached considerable importance to "clarity about boundaries - of confidentiality, of time, of any action that may be taken. This gives them the information they need to be able to decide what they wish to share."
Ms Houston said the factors that stop young people seeking help include fears that the intervention of adults will do something that will make matters worse, not being able to talk privately and in confidence, a fear of losing the little control they have and not being believed or taken seriously.
She warned, however, that counselling was not a soft option. "It often takes enormous courage to seek help. Many calls to Child-line are silent and children tell us sometimes that they have phoned 10 or 12 times before they have plucked up the courage to speak. Boys in particular struggle to share problems."
Ms Houston said that specific skills were required in working with children.
The launch of the guidelines, produced by the British Association for Counselling and Psychotherapy, also heard calls for staff in schools to have support. Mr Doig pointed to an increasing number of calls taken by his association's helpline. "These pleas for help are all the more striking when you realise that they come from school leaders."
Mike Finlayson, chief executive of Teacher Support Scotland, said support for teachers and pupils should be part of "a virtuous circle". Teaching was inherently stressful and staff had to be equipped to cope.